Palaeoenvironmental and Archaeological Implications of a Sediment Core from Polje Čepić, Istria, Croatia Andrea L. BALBO1, Maja ANDRIČ2, Josip RUBINIĆ3, Andrea MOSCARIELLO4 and Preston T. MIRACLE1 1. PALAEOEnvIROnMEnt And ARChAEOLOgy: OvERvIEw On thE PROjECt AIMS This paper further develops the study of the prehistoric population of Istria launched a decade ago (MIRACLE & FORENBAHER, 2006). The initial study focused on the exploration and excavation of archaeological cave sites. In the last two years, we have undertaken a new geoarchaeological study of open environments situated around Polje Čepić, not far from some of the richest caves excavated in Istria (Fig. 1). Our overall aim is to provide palaeoenvironmental and archaeological infor- mation for land and water management in karstic areas of the Mediterranean realm. The Slavic word polje literally translates into field or plane. In karstic geomorphology polje indicates a tectono-karstic depression typically found in Dalma- tia and often occupied by a karstic lake (JENNINGS, 1971, 1985; O’SULLIVAN, 2004). The Holocene envi- ronments and landscapes of Istria are not well known, mainly due to the lack of suitable palaeoecological sites. In addition, the neighbouring locations studied so far are close to the Adriatic coast and reflect changes over wide areas for the mid and late Holocene (BEUG, 1967, 1977; CULIBERG, 1995, 1997). At the few inland sites that have been investigated, for example Zajezeri– Vodenjak (CULIBERG, 1995) and Prapoče (ANDRIČ, 2001, 2006), pollen and organic remains are only sel- dom preserved in Holocene sequences. Polje Čepić con- stitutes an optimal site for the development of a com- prehensive palaeoenvironmental/palaeoclimatic study in the east-Adriatic region because its position and size are likely to reflect both local and regional changes, and organic and pollen preservation is excellent. Our research aims to: (1) determine for how long a lake had existed in Polje Čepić before 1932; (2) deter- mine whether people had been living around the polje in prehistoric times, and how they could have contrib- uted to the progressive siltation of the basin; (3) explore the relationships between the population of open-air landscapes and the environmental changes that took place during the Holocene. In 2004 we undertook a sys- tematic survey to identify open-air archaeological sites and reconstruct past environmental conditions around Geologia Croatica 59/2 109–124 7 Figs. 1 Tab. ZAGREB 2006 Key words: Holocene, Lake sediments, Geoarchaeo- logy, Palynology, Mediterranean karst. 1 Department of Archaeology, University of Cambridge, Cambridge CB2 3DZ, United Kingdom; e-mail: alb55@cam.ac.uk, ptm21@cam.ac.uk 2 Institute of Archaeology, ZRC SAZU, Novi trg 2, SLO-1000 Ljubljana, Slovenia; e-mail: maja.andric@zrc-sazu.si 3 Faculty of Civil Engineering, University of Rijeka, Viktora Cara Emina 5, HR-51000 Rijeka, Croatia; e-mail: jrubinic@gradri.hr 4 Department of Geography, University of Cambridge, Downing Place, Cambridge CB2 3EN, United Kingdom; e-mail: a.moscariello@shell.com Abstract Palaeoenvironmental and archaeological records provide an invalu- able framework for land and water management in karstic areas of the Mediterranean realm. We present the results from analyses carried out on three segments of a sediment core extracted in 2004 from a portion of Polje Čepić (Istria, Croatia), a tectono-karstic depression covered in water until artificial drainage took place in 1932. We used bulk sediment analyses, pollen analysis and radiocarbon dating to assess the possible contribution of people to the progressive siltation of the lake, and compared our results with recent archaeological discover- ies made on the polje margins. The dating of the sequence points to the presence of a predominantly wet landscape at the coring location since at least 7000 years cal BP. The coincidence of cereal type pollen grains with several open-air archaeological sites indicates that small- scale agricultural practices possibly developed around the polje in Neolithic times, ca 6500 years cal BP. Concentrations of charcoal in the sediment core at this time suggest the use of fire clearance as part of the agricultural practice. During the Bronze and Iron Ages, the possible intensification of forest clearance and agricultural practices is indicated by: (1) an increase in the number and type of archaeological sites found around the polje; (2) a more open plant landscape in the upper part of the ana- lysed sequence; and (3) a three-fold increase in the sedimentation rate, possibly starting as early as 4000 years cal BP. Wetter climate condi- tions and higher erosion of the surrounding slopes probably led to the progressive siltation of the lake. Finally, in 1932 the lake was artifi- cially drained and Istria lost its largest natural basin of fresh water. 110 Geologia Croatica 59/2 Polje Čepić (BALBO et al., 2004). We discovered four- teen previously unknown prehistoric areas, and test- excavated four of them (BALBO, 2006; BALBO et al., in press). In addition, we extracted an exploratory core from the polje, the analysis of which is presented in this paper. 1.1 the study area Polje Čepić is situated in the eastern–central part of the Istrian peninsula, at the northernmost tip of the Adriatic Sea (Fig. 1). Most historical maps of Istria, dating back to the 16th century show that Polje Čepić was occupied by a shallow lake, until its complete drainage in 1932 (PARENZAN, 1928; LAGO & ROSSIT, 1981; BAL- BO, 2005). The Boljunšćica River constituted its main natural inlet. Most of the lake water used to outflow through underground sinkholes, mainly situated on the southern margin of the polje. When high water levels occurred, the lake drained into the Raša River (Fig. 1). The polje formed following Miocene tectonic move- ments and is situated on an elongated depression devel- oped on the western side of a structurally complex anti- cline (MIHLJEVIĆ, 1998; ROGLIĆ, 1950). The polje is surrounded and underlain by terrigenous Eocene bed- rock, flysch (ŠIKIĆ & POLŠAK, 1973). These flysch deposits form a low relief landscape on the eastern and northern parts of the polje, characterised by a network Fig. 1 Location of Polje Čepić within Istria and Croatia (a). A three-dimensional model of the study area shows (b): the approximate extent of the lake occupying the polje before 1932 (1), the location of the core (2), the course of the Boljunčica River (3), the main artificial channel (4) connecting the Boljunčica River to the Rakita channel (5) and the Raša River (6), the artificial tunnel through which the lake was drained (7), Plomin Bay (8), and Mount Učka (9). 111Balbo et al.: Palaeoenvironmental and archaeological implications of a sediment core... of shallow river incisions. To the east the polje is con- tained by the western flank of a N–S trending anticline, characterised by thrust structure of Cretaceous carbon- ates (HERAK, 1991). This flank forms the steep slopes of the Učka Mountains incised with a series of deep gul- lies. Most soils within the polje catchments developed both on terrigenous rocks of the Flysch zone and on the carbonates of the Učka/Ćićarija and Central Istria zones (DURN, 2003; ŠKORIĆ et al., 1987). 2. CORIng tEChnIquE The exploratory core presented here was extracted from Polje Čepić in August 2004, at the geographical position N 45°.18759, E 14°.15909, at an altitude of 27 m asl. The drilling equipment used was a rotation/percussion wire line drill, normally used for commercial geological research. The core was recovered in 12 drives, reaching a maximum depth of 17.43 m. Due to the nature of the coring equipment, portions of the core were deformed during its extrusion (Fig. 3a). The top portion of each drive had deformations caused by the rotation of the coring piston and the water-pressure extrusion technique (LEROY & COLMAN, 2001). All segments of the core were extruded into half-cut pipes and sealed with cling film and aluminium foil to preserve moisture and avoid penetration of light. Each segment was labelled and stored in a cold room at the Archaeological Museum of Istria (Pula), before being transported to Cambridge for sampling and analysis. The disturbed segments of the core were not analysed, and archive core segments were kept for future reference. Although the three undis- turbed core segments from the lowermost three drives are discontinuous, they provide useful information about the history of the basin. Analyses of the core were carried out at the Department of Geography, Quaternary Research (QR), University of Cambridge, at the Insti- tute of Archaeology, Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, and at the Institutes of Botany and Geology, University of Bergen. Accelerator mass spectrometry (AMS) radiocarbon dat- ing was carried out at the Poznan Radiocarbon Labora- tories (PRL). 3. MEthOdS 3.1. Radiocarbon dating Seven samples for AMS radiocarbon dating were pre- pared following the protocols established at the Norwe- gian Past Environments & Climate Centre (NORPEC) and at QR. Based on sediment analyses and on the obtained dating we decided to restrict our analyses to the three undisturbed segments presented in this paper. The equipment was washed before each operation and all samples were taken in 1 cm slices. The materials to be dated were separated from the core with steel spatu- las, sieved through a 100 µm mesh, and picked up with steel forceps under the stereomicroscope. Non-carbon- ised terrestrial plant remains and carbonised remains were sampled for dating. Aquatic plant remains were excluded in order to avoid distortion due to the reser- voir effect (BJÖRCK & WOHLFARTH, 2001; GEYH et al., 1998). Sediment residue was removed from the plant materials under the stereomicroscope using soft steel forceps and a synthetic pencil. Plant remains were identified as precisely as possible before being dried in the oven at 60°C, weighed, and sent to PRL. 3.2. Sediment analysis Non-destructive methods were initially applied to deter- mine the best-preserved parts of the core and the loca- tion of irregularities, clasts, and laminations. The low- ermost 10 m of the core were X-rayed using a SMR Ltd NOVA HF 30 set at 68 kV and 20 mA, to obtain good luminosity and contrast. Rapid film with no grid was used, maintaining a constant focus of 100 cm. Whole- core magnetic susceptibility (MS) measurements were taken using a Bartington magnetic susceptibility meter connected to a PC and a loop sensor (NOWACZYK, 2001). Following these first analyses the core segments were split and described. The first description of the split core segments involved the semi-quantitative col- our determination of the sediments using a Munsell soil colour chart. A fully quantitative digital colour (DC) determination was carried out with a Stellarnet Spec- trometer. Sediment samples were taken at regular inter- vals of 2 cm, with a 1 cm3 brass volumetric sampler. Samples for particle size determination (PSD) were put in 50 ml test tubes, a 4.5% sodium pyrophosphate (Na4P2O7) solution was added and test tubes were left in a water bath at 90°C (194°F) for 5 hours to disperse clay particles. Each sample was then centrifuged and run through a Malvern Mastersizer 2000, to meas- ure particles sizes between 0.02 and 2000 μm (LAST, 2001). Further subsamples were run through the Mas- tersizer two more times: first after eliminating the OM in a 30% hydrogen peroxide solution (H2O2), and sec- ond after treatment in a 7% hydrochloric acid solution (HCl) to eliminate carbonates. Particle size categories are as defined in LAST (2001). The relative moisture, OM, charcoal, and carbon- ate (CaCO3) contents in the sediments were measured through loss-on-ignition (LOI), using a 1000oC muffle furnace. All samples were weighed, kept at room tem- perature (20°C) for 3 hours, and reweighed to deter- mine percentage moisture content. Samples under- went three more overnight (12 hours) heating cycles at 400°C (752°F), 480°C (896°F) and 950°C (1742°F). At the end of each heating cycle, samples were cooled at 105°C and weighed. The mass loss between 105°C and 400°C was used as a proxy for OM content, while the mass loss between 105°C and 480°C was assumed to represent the content in charcoal. Finally, the mass loss between 105°C and 950°C was taken as an indicator of the carbonate content (NELSON & SOMMERS, 1996). 112 Geologia Croatica 59/2 Fig. 2 Comparison of age–depth models from the Adriatic Sea and circum-Adriatic lakes. All age–depth models, excluding that for Polje Čepić, have been drawn based on published pri- mary data. All dates were cali- brated using Calib Rev 5.0.1®. Ages on the horizontal axis are in years cal BP, depths below the sediment surface are in metres. A polynomial trend-line of order 2 has been fitted to each age–depth model. Polje Čepić (A). Malo Jezero (B) Croatian lake on the Island of Mljet, Dalmatia; two age–depth models are proposed: black line (JAHNS, 2002), and grey line (WUNSAM et al., 1999). Lake Monticchio (C) Italian volcanic lake (ALLEN et al., 1999; WULF et al., 2004). Lake Ioannina (D) Greek polje lake in Epirus (LAWSON et al., 2004). RF93–30 (E) Adriatic core (OLDFIELD et al., 2003). AD91–17 (F) Adriatic core (SANGIORGI et al., 2003). A B C d E F 113Balbo et al.: Palaeoenvironmental and archaeological implications of a sediment core... Photographs were taken with a scanning electron microscope (SEM) from core segment S2, to determine the origins and nature of the carbonates present in the sediments. Samples were coated with 30% gold and 70% palladium using a Polaron Equipment Limited Self Coating Unit E5100, before observation on a Philips XL30FEG SEM. 3.3. Pollen analysis Samples for pollen analysis were collected using a 1 cm3 brass volumetric sampler. Standard laboratory procedures were used for sample preparation (7% HCl, 10% NaOH, 40% HF, acetolysis, staining with safra- nine, silicone oil, method B in BERGLUND & RAL- SKA-JASIEWICZOWA, 1986; BENNET & WILLIS, 2002). Two tablets with a known number of clubmoss spores (Lycopodium) were added to each sample dur- ing the first stages of laboratory preparation, in order to determine pollen concentration (STOCKMARR, 1971). A Nikon Eclipse E400 light microscope at 400x mag- nification was used. Pollen types were identified by comparison against pollen keys (MOORE et al., 1991; REILLE, 1992, 1995) and the pollen reference collec- tion held at the Institute of Archaeology in Ljubljana. Microscopic charcoal from each sample was also count- ed, considering two size classes: <40 µm and >40 µm. 4. RESuLtS FROM thE Study OF POLjE ČePIĆ SeDImeNtS 4.1. Preliminary age–depth model Seven radiocarbon dates were obtained from the sedi- ment core extracted from Polje Čepić, three of which gave reverse ages. Each of the three lowermost core drives considered in this thesis measured ca 2-m in length. Two of these core drives had a diagnostic V- shaped ‘wavy’ feature at ca 50 cm from their base (Fig. 3a). Such features can sometimes result from sudden alluviation, with consequent mixing of sediments, ulti- mately leading to reverse ages. In alternative, mixed sediments and reverse ages can result from distortion of the core during extrusion. In this case study, the 2 V- shaped features occur at the same point (50 cm from the base) in two different core drives, in axis with the verti- cal coring direction. Based on the recurrence of these factors, the three reverse dates were attributed to defor- mation of the core drives during extrusion. As a result, the three reverse dates (1532 cm, 1665 cm and 1678 cm depth) were dismissed. The portions of each core drive situated above these V-shaped features were therefore excluded from further analysis. The final age–depth model is based on the remaining 4 dates. Dates were calibrated using Calib Rev 5.0.1® based on the IntCal 04 calibration dataset (Table 1) (STUIVER & REIMER, 1993; STUIVER et al., 2005). Median ages were used to create a preliminary age–depth model (Fig. 2a). 4.1.1. Comparison with age–depth models from neighbouring regions Attempts to compare heterogeneous records (e.g. from ice, sea, and lakes), covering different spatial and tem- poral scales, have allowed correlating climatic and environmental events at local, regional, and global lev- els (BARTLEIN, 2007). The age–depth model obtained for Polje Čepić has been compared with five continen- tal and marine sediment sequences recovered around the Adriatic (Fig. 2): (a) Three age–depth models were obtained from continental sequences extracted from Lake Ioannina (also Pamvotis, Greece – LAWSON et al., 2004), Malo Jezero (Island of Mljet, Croatia – JAHNS & VAN DEN BOGAARD, 1998; WUNSAM et al., 1999; JAHNS, 2002), and Lake Monticchio (Cen- tral Italy – ALLEN et al., 1999; WULF et al., 2004); (b) Two age–depth models were based on marine sediment sequences from Adriatic cores RF93–30, and AD91–17 (OLDFIELD et al., 2003; SANGIORGI et al., 2003). The discontinuity of the record recovered from Polje Čepić did not allow a multi-proxy correlation. The pre- liminary comparison proposed here is solely based on radiocarbon dating and has been restricted to the past 10000 years. Laboratory Midpoint Material weight Conventional Age years cal Age years cal Median years code (gr) age 14C BP BP (1σ) BP (2σ) cal BP Poz-10877 1351 (S3) bark, stem, 1 Scirpus seed 0.0051 3620±35 3887–3978 3839–4074 3931 Poz-10878 1532 bark 0.0281 3490±35 dismissed Poz-10880 1568 (S2) 9 Scirpus seeds 0.0104 5370±35 6119–6273 6007–6279 6185 Poz-10881 1582 (S2) bark 0.0159 5720±40 6446–6560 6412–6633 6514 Poz-10882 1665 bark, stem, 1 Scirpus seed, charcoal 0.0122 5290±40 dismissed Poz-10883 1678 bark, charcoal 0.0105 4740±35 dismissed Poz-10884 1686 (S1) charcoal (Juniperus) 0.0152 6040±40 6802–6945 6759–6997 6889 Poz-12231 1678 bark, charcoal 0.0105 4765±35 replica Poz-12232 1686 charcoal (Juniperus) 0.0152 6080±35 replica Table 1 Results from the AMS dating. Following the occurrence of reverse dating, PRL repeated two samples at 1678 cm and 1686 cm depth obtaining similar results to those from the original analyses. 114 Geologia Croatica 59/2 Fig. 3 Core log and sediment description. (a) Example of a V-shaped core deformation. In contrast with Polje Čepić, Malo Jezero (a coastal Dalmatian lagoon) features a decreasing sedimentation trend throughout the Holocene. A linear sedimentation trend is noticed at Monticchio Lake, a volcanic lake, pointing to constant sediment accumulation through- out the Holocene. Among the continental sequences, Lake Ioannina (a shallow polje lake) shows a sedimen- tation trend similar to Polje Čepić (BROUSOULIS et _ .. ,,.. 'M •• •• •• •• ••• ... .... •• -. •• •• •• ~. •• •• •• .~ .~ ... ,,,. .~ .~ .m . ~ ... --­~ 130151380 _ "!I' OY." '' '_I , !Y"",," (0l' ___ 1 .... S,,"'r-.. _IIP) ,= ,-, ... - 5'1'2 SI' (1,1) = '_'lI' "" 5'1'2.51'11" ) , ,3U,.,:M_ .,., .... , I") = ,""","", an 5Y2S1H") ~i~"a. ,CS2 ~ ,""'.,5el",,, .. "''''''1'') =. ,5&1_,57, "'" 5YUrq .. ) ~"S ''''('''''''''''''''''''' = ,.,,., ... "" ... "',"', (III ~ .. S ,:w,>7"" .. ...,..tJP ~" '~H"_ 1Vl.5I1 'Y2,~ (100) ..... S, ... ~_"" " 111),1111·,1.03 "" 1Y7I1,"'1 2''fMI(_1 _ _ ........... S ""-_ ... ~ "--• ""'_<10>""''' 80%), followed by clay (8–10%), and sand (5–10%). The distribution of particles through core sediment S2 shows a generalised increase of clay size particles (5 to 15%) compared to silt and sand particle sizes after treatment with H2O2. The grain size distribution pattern remains similar after treatment with HCl. Sand size par- ticle peaks occur at 1578 cm (30%), and 1568 cm and 1558 cm depth (40%). In core section S3 the particle distribution shows lit- tle change after treatment with H2O2 and HCl. There is a generalised gain of about 20% on the clay particle size compared to sand size after treatment with H2O2, while changes are minimal after treatment with HCl. Two contrasting trends can be observed. A first one towards decreasing particle sizes up to 1366 cm depth, and a second one towards sand sized particles towards the top of this core segment. Core segment S3 is the most poor- ly sorted before treatment with H2O2 and HCl, while S2 is the most poorly sorted after OM and carbonates are eliminated. 4.2.3. Magnetic susceptibility MS values remain constant throughout core segment S1, where they reach the highest readings. MS values decrease gradually through core segment S2, reaching minimal values just over 1.0 SI units. As for core seg- ment S3, MS values increase steadily, stabilising around 4.5 SI units above 1365 cm depth. 4.2.4. Loss-on-ignition In core segment S1 unit MCS1 shows a very stable pat- tern throughout LOI analysis, with a net prevalence of silicate residue (90%) and low OM (5–7%), carbon (less than 2%), and CaCO3 (5%) content. Inclusive mean is stable around 6.5 φ, pointing to medium and coarse silts as the predominant particle sizes. In core segment S2 inclusive mean values are generally lower than those registered for core segment S1. A general trend is observed, with increasing particle sizes towards the top, where particle sizes from the silt–sand boundary are the most represented. A peak in carbonate content is record- ed at 1580 cm depth, followed by a rapid increase in the amount of carbon (4 to 6%) and OM (10 to 35%). The highest peak in carbon content is recorded at 1568 cm depth. Clay-size detritus is the main component of the carbonates from this core segment. Some sponge nee- dles and diatom fragments are present (Fig. 5), as well as infrequent shells and ostracods. Core segment S3 is generally dominated by silicate residue, stable around 116 Geologia Croatica 59/2 80%. This core segment is characterised by a progres- sive decrease in OM, in coincidence with a progressive increase in carbonates. 4.3. Pollen record Polje Čepić is located in a relatively large tectonic depression. Historically, the polje has been occupied by a lake extending over an area up to 6 km2 (PAREN- ZAN, 1928). Therefore, the pollen record from this basin is likely to represent past plant composition at local, extra-local and regional scales. While the effects of the early introduction of local small-scale forest clearance and agriculture are detectable through pollen analysis in small basins (with <30 m diameter) they are overwhelmed by the regional pollen record deposited Fig. 4 Results from MS, PSD, and LOI. MS is measured in SI units; LOI results are presented in %; inclusive mean is measured in φ; clay, silt and sand proportions are presented in % and in a cumulative way following the results from PSD analyses after treatment with Na4P2O7 (dark grey), H2O2 (grey) and HCl (light grey). 117Balbo et al.: Palaeoenvironmental and archaeological implications of a sediment core... in larger basins (JACOBSON & BRADSHAW, 1981), such as Polje Čepić. Nevertheless, the accurate observa- tion of seemingly minimal changes in the pollen record recovered from larger basins can be used to detect the possible effects of agro-pastoral practices on changes in plant and forest composition (Fig. 6). Preliminary examination of the three core segments showed that pollen was only preserved in the upper two segments. Pollen is not preserved throughout the low- est core segment S1. No pollen is preserved in the low- est levels of core segment S3, at 1384 cm and 1390 cm depth. The best pollen preservation is recorded for the middle core segment S2, with pollen concentrations reaching 7000–14000 grains/cm3. A major peak in the input of coarse microcharcoal (>40µm) is registered at 1568 cm depth. Only one sample was analysed from core segment S3 at 1360 cm depth, where pollen con- centration is lower than that observed for core segment S2, with less than 2000 grains/cm3. Throughout most of the time span covered by core segments S2 and S3 the environment around the coring location was wet enough to allow pollen preservation. The pollen record suggests that beech (Fagus) was an important tree taxon before 6500 years cal BP, which is consistent with charcoal and phytolith analyses from the archaeological site of Pupićina Cave where beech abounds in the mid-Holocene layers (FLETCHER, 2002; FLETCHER & MADELLA, 2006). This is prob- ably because the Ćićarija and Učka Mountains pro- vide an orographic barrier to the north and east (up to 1394 m asl) of the study area, retaining the clouds com- ing from the Adriatic Sea, and increasing precipitation. Pollen diagrams from Škocjanski Zatok near Koper suggest that the mid-Holocene vegetation of northern Istria was dominated by broadleaved taxa, with a high percentage of beech (CULIBERG, 1995, 1997). Con- versely, pollen analyses from Vrana lake, on the island of Cres, 50 km eastwards, suggest that oak (Quercus) was there the most important tree taxon throughout the Holocene, although an increase of beech and fir (Abies) occurred after ca 9600 cal BP (SCHMIDT et al., 2000). 5. IntERPREtAtIOn OF CORE EvIdEnCE 5.1. S1 (1743–1685 cm, previous to ca 6830 years cal BP) The lowest part of core section S1 (Fig. 3, unit D) has not yet been dated, but is significantly different from the others studied here. Unit D is the result of a mas- sive colluvial discharge and therefore a sedimentation gap could exist between units D and MCS1. If so, unit D could have been deposited during a period of rapidly changing climate at the lateglacial–early Holocene tran- sition. Alternatively, the predominant siliceous compo- nent, with its steady trend towards more laminated and finer particle sizes and the almost complete absence of OM and pollen could be due to slope failure associated with a major tectonic event, such as the one recorded on Mljet Island by WUNSAM et al. (1999). High MS values in this part of the core point to a significant, and perhaps rapid, input of mineral sediments. The laminat- ed clays and silts of unit MCS1 and its stable and well- sorted particle size pattern seem to reflect the establish- ment of a lake fed by intermittent streams. Fig. 5 Six photographs of the sediments taken with SEM. The top three photos were taken from 1568 cm depth, the bottom ones from 1580 cm depth. Photos 1, 5 and 6, show clay particles and structures (5) potentially indicating the formation of shallow hydromorphic soils during low water stands; photos 2 and 3 a sponge spicule, and photo 4 part of a diatom. 1 2 3 4 5 6 118 Geologia Croatica 59/2 Fig. 6 Pollen diagrams (selected taxa). Radiocarbon dates are reported in years cal BP. The quantity of individual pollen taxa is presented in percentages (calculated from the sum of all terrestrial-taxa and spore pollen). For summary diagram the percentage of trees and shrubs (AP) and herbs, spores and aquatics (NAP) was calculated from the sum of all taxa. The sum of terrestrial taxa and spores is in absolute numbers. Pollen and charcoal concentration are given in number per cm3. All pollen data is presented (a) as well as a detail of the results obtained for S2 alone (b). In (a) data are presented as simple bars in reason of the large gap between S2 and S3. The only exception was made for the AP/NAP ratio, where bars are linked by dashed lines to show the changing AP/NAP trend between samples 1560 and 1360 cm depth. Abbreviations to be read as follows: Quercus i. (ilex type), Carpinus o. (orientalis type), Fraxinus e. (excelsior), Fraxinus o. (ornus type), Cereal (type), Plantago l. (lanceolata type), Compositae lig. (liguliflorae type), Typha l. (latifolia type) and Sum terr. (ter- restrial) taxa and spores. Ind – indeterminable. Italic is used for taxa if pollen is determined to genus level, while normal letters are used for taxa if pollen is determined to family level. f f f' F F F -----' f F F J F .1 It f f F F f f f 119Balbo et al.: Palaeoenvironmental and archaeological implications of a sediment core... 5.2. S2 (1598–1550 cm, ca 6600–6000 years cal BP) Core segment S2 probably represents a progressive low- ering of the water level in the polje. The lower portion of this core segment, represented by units LCS1 and CSS, contains microlaminations and occasional fine sand laminae. The intermittent input of coarser materi- als represented by the sand peaks at 1578, 1568, 1554 and 1558 cm depth could be due to sudden wet and ero- sive episodes, but generally this core segment seems to suggest the onset of progressively drier conditions. The clay particles and structures characterising the sediments from unit CSS (Fig. 5) potentially indicate the formation of shallow hydromorphic soils during low water stands. The peak in carbonates at 1580 cm depth could be a consequence of a higher concentration of microorgan- isms and aquatic plants fixing CaCO3 in the lake, due to lower water levels (MACKERETH, 1966; KELTS & TALBOT, 1990). This carbonate peak is followed by a significant increase in OM and charcoal within the lake sediments. The content in OM increases toward the top of core segment S2, in units OCS1, LCS2 and OCS2, also indicating the establishment of low water levels. Furthermore, the relatively low MS readings from this part of the core point to lower terrigenous input with sil- iceous sediments only episodically reaching the basin. Tree pollen is dominant throughout core segment S2, constituting ca 90% of the total pollen sum: the record suggests that ca 6600 years cal BP (1590 cm depth) the landscape around Polje Čepić was covered by a thick forest of shade-tolerant beech (40%), and oak (26%), fir (11.8%), and hazel (Corylus 5.8%). Herb-type pollen remains stable around 2% throughout core segment S2, but after 6500 years cal BP forest composition changed appreciably towards a more open type of forest, char- acterised by the decline of beech (27.3%) at 1568 cm depth (ca 6150 years cal BP), and an increase of oak (29.8%) and hazel (11.7%). 5.3. S3 (1398–1345 cm, ca 4420–3870 years cal BP) The absence of pollen grains at 1384 and 1390 cm depth, as well as the presence of lignite (unit L) and the abundance of only partially humified OM within unit OCS3 suggest a low water level stand at the coring site. The 3 units L, OCS3, and LCS2 probably represent a transitional phase from dry conditions with peat forma- tion, to a wetter environment with deepening water, also indicated by laminated and massive clayey and clay-rich silt (units LCS2 and MCS2) towards the top of core seg- ment S3. The top unit MCS2 contains abundant amounts of shells, indicative of established limnic conditions at the top of this core segment. At ca 3900 years cal BP (1360 cm depth) Polje Čepić was surrounded by relatively open, mixed wood- land. When compared to core segment S2, S3 denotes a relative decline of oak and other tree pollen taxa, with trees and shrubs representing only 70% of the total pol- len sum. This decline and the simultaneous increase of non-arboreal taxa, with herbs reaching 7.3% of the total pollen sum, indicate a more open landscape. 6. dISCuSSIOn This study covers three time periods between ca 7000 years cal BP and 3800 years cal BP providing new evi- dence on palaeoenvironmental and vegetation change in Polje Čepić and its surroundings. Using a combina- tion of archaeological and palaeolimnological evidence, we suggest the following account of Polje Čepić and the people living on its margins during those periods (Fig. 7). 6.1. Archaeological evidence A recent archaeological survey carried out on the mar- gins of Polje Čepić, provides strong evidence for the presence of people during the last 25,000 years (BAL- BO, 2006; BALBO et al., 2006). The periods covered by the core segments are well represented in the archaeo- logical record. Human occupation for the period covered by S2 is characterised by five open-air lithic scatters on the margins of the polje. Organic material was not pre- served at these locations, owing to exposure to weather- ing and modern agricultural practices. In the absence of absolute radiocarbon datable materials, the age of these archaeological assemblages was inferred by association with radiocarbon-dated cave sites studied in the wider region. In particular, the lithic assemblages from the open-air sites discovered at Frankoli and Ivšišće present artefacts that could be associated with those found at Pupićina Cave, located less than five kilometres north- wards (MIRACLE & FORENBAHER, 2005; BALBO et al., 2006). Within the lithic assemblages discovered at Frankoli and Ivšišće three obsidian fragments of probable Lipar- ian origin were found (BALBO, 2006; BALBO et al., in press). Fragments of the same raw material were found in the Late Neolithic horizon G at Pupićina Cave, dat- ed between 6219 and 6477 years cal BP at 1σ (MIRA- CLE & FORENBAHER, 2005). The most recent peri- ods, covered by core segment S3, are associated with the presence of large communities living around Polje Čepić. Such communities have been well document- ed (PETRIĆ, 1979). Kožljak and Kršan are two major examples of late medieval settlements erected upon protohistoric hillforts (castellieri) dating back to the 2nd millennium BC. In a recent archaeological survey a probable Bronze Age settlement was (re)discovered on the northern tip of the polje (BALBO et al., 2006), on a hilltop locally known as Gradina (MARCHESETTI, 1903). Six previously unknown lithic scatters and buried agricultural soil horizons possibly of the same age, were also discovered on the margins of the polje (BALBO et al., 2006). 120 Geologia Croatica 59/2 6.2. Palaeolimnological evidence The neotectonic depression represented by Polje Čepić has been occupied by a wet, mainly lacustrine land- scape, for most of the time span covered by the present study. Our analyses suggest that the water body and surrounding vegetation underwent significant changes during these periods of time. The archaeological, sedi- mentological, and palynological records, notably the increase in non-arboreal pollen (NAP) in S3, support the hypothesis that forest clearance by people living on the margins of the polje contributed to such chang- Fig. 7 Diagram summarising the main results issued from the present study. , If ~ i::.. ,p ~¢o::-'? • , .0 , ~ .~.p i ' .§>o~ "l'~ ~& 18> p:'b.[J ~'" ,lect,,';I' i 6' • b' &~'/ 350 Vrana - $ potsherds " , 1355 0 0 ~ I , "" I 1365 • ., , ! 0 1370 I i • h 1375 , • • , ' -1380 0 , ': ~ LCS2 , , j] 1385 0 " OCS3 • • [~ "90 • L 1395 '. - '''0 OCS2 • 0 1555 0 • .- • " "'" ~ 0 ---LCS2 OCS1 0 • , cvItiv~ '565 • '''' I • sm ... seale fo40 µm) points to its input in the basin from relatively short distances within its catch- ments (WHITLOCK & LARSEN, 2001). After ca 6150 years cal BP (1568 cm) and within about a 100 years, a significant forest composition change seems to have taken place around Polje Čepić. Beech declined in favour of oak, indicating the establishment of a more open forest, dominated by photophilic (light-demand- ing) oak. At the same time cereal-type pollen grains made their first appearance in the region, just after 6150 years cal BP at 1562 cm depth. Five of the sites recently found on the margins of the polje have been associated through typochronological comparison with the Late Neolithic horizon G dug in the nearby Pupićina Cave, dated between 6219 and 6477 years cal BP. The simul- taneous appearance of cereal-type pollen grains and the unusual concentration of microcharcoal (also revealed by LOI analysis) indicate a possible link between the decreased tree cover and the introduction of small-scale forest clearance and burning by Neolithic settlers just before 6000 years ago. Our preliminary age–depth model, with its increased sedimentation rate after 4000 cal BP, is consistent with the model proposed by OLDFIELD et al. (2003). The lowermost 3 m of sediments accumulated at the core location over 3000 years, between 7000 and 4000 years ago, at an average rate of 1 mm/yr. In contrast, the aver- age sedimentation rate in the top 14 m of the core tri- pled in the last 4000 years to 3.5 mm/yr. Sedimentolog- ical analyses of the sediments for the period represented by S3 point to higher water level in the shallow lake occupying the polje. At the same time, a steady increase in magnetic susceptibility throughout S3 indicates an increase in the input of sediments within the polje. Such peaks in MS are often linked to periods of deforestation, and consequent erosion of mineral soils (SANDGREN & SNOWBALL, 2001). In addition, the comparison between the pollen record from core segment S2 and the sample from core segment S3 shows a trend toward an ever more open forest environment. In core segment S2 beech decreases (40 to 26%) to the slight advantage of oak (26 to 30%). In core segment S3 beech and oak decrease even further, respectively reaching 16% and 20%. This trend in vegetation change is also reflected by the decreasing ratio of arboreal versus non-arbore- al plants (AP/NAP), indicating a shift towards a more open landscape. We propose that the concurrence of wetter conditions, and perhaps the cumulative intensi- fication of forest clearance and agro-pastoral practices, may have resulted in a sharp acceleration of the silta- tion of the lake occupying Polje Čepić. In the wider region, the study carried out by OLD- FIELD et al. (2003) on core RF93–30, extracted from the Adriatic, revealed a sedimentary pattern similar to that obtained for Polje Čepić. This was interpreted as being the result of increased soil erosion in the Po plain due to the intensification of agro-pastoral practices dur- ing the Bronze Age. Similarly, the studies carried out at the nearby Vrana Lake suggest that Bronze Age com- munities played an important role in the shaping of the local landscape (SCHMIDT et al., 2000; MIKO & MESIĆ, 2004; MIKO et al., 2005). Potsherds embedded within colluviums were found on the margins of Vra- na Lake (Island of Cres), and dated between 3853 and 3926 years cal BP at 1σ range (median of 3883 years cal BP from the original date of 3580±40 years uncal BP in MIKO et al., 2005). This age range has been correlated with a greater input of sediments in the lake, and seems to coincide with the beginning of oak forest clearance through burning between 3693 and 3895 years cal BP at 1 σ range (median of 3796 years cal BP from the origi- nal linear extrapolated date of 3518±80 years uncal BP in SCHMIDT et al., 2000). 7. AvAILABLE PROxIES FOR FuRthER StudIES Microscopic observations carried out on the core sedi- ments have revealed the presence of several other prox- ies available for use in palaeoclimatic research. Among them were shells, diatoms, midges (Chironomidae and related diptera), and ostracods. Some of them have been sampled and kept for future observations. Reference samples have also been collected from several ponds and rivers within the catchments of Polje Čepić for the isotopic study of ostracods and water. Seeds and other plant macroremains also abound. Moreover, the location and characteristics of Polje Čepić makes it an optimal site for furthering palaeoenvironmental and palaeocli- matic research in connection with other continental and marine sequences available in the Mediterranean realm. 8. COnCLuSIOnS In this paper we have demonstrated the potential of Polje Čepić for enhancing our knowledge of the past in the Istrian peninsula and beyond. We propose that lacus- trine/wet landscapes have characterised Polje Čepić and its surroundings before historical times. Polje Čepić, and other poljes, are ideal sites to study the introduc- tion of agro-pastoral practices and their effects on the transformation of the Mediterranean realm during the Neolithic and later times. Using sedimentological and palynological analyses we have detected hydrologi- 122 Geologia Croatica 59/2 cal and palaeoclimatological variations affecting Polje Čepić and its surroundings. We have shown that people played a significant role in shaping this typical Mediter- ranean karstic wet landscape. Palaeoenvironmental and archaeological data sug- gest that the introduction of agro-pastoral practices con- tributed to the transformation of the area of study. Spe- cifically, we propose that: (1) around 6500 years ago, people may have introduced forest clearance by fire in tandem with small-scale agricultural practices on the margins of the lowered karstic lake, triggering a slight change in forest composition near Polje Čepić; (2) around 4000 years ago wetter climatic conditions and perhaps the intensification of agro-pastoral practices, coincide with appreciably more open vegetation; (3) these factors probably resulted in increased erosion and sedimentation, leading to the siltation of the lake until its artificial drainage in 1932. Acknowledgements The authors wish to thank Steve BOREHAM, Chris ROLF, and Phil GIBBARD (Department of Geog- raphy, University of Cambridge), Tony BURGESS (Department of Anatomy, University of Cambridge), Gilly THORP (Veterinary School, University of Cam- bridge), Milan MIHOVILOVIĆ and GEO5 (Rovinj), Hillary and John BIRKS, Richard TELFORD and Hel- len SCHJÖLBERG (Institute of Botany, University of Bergen), Michael TALBOT and Stig MONSEN (Insti- tute of Geology, University of Bergen) Nada KRSTIĆ (Beograd), Elsa GLIOZZI (Dipartimento di Scienze Geologiche, Universitá degli Studi Roma 3), Maria Letizia FILIPPI (Museo di Storia Naturale, Trento) and Marco MADELLA (ICREA Barcelona). We are indebt- ed to the Marie Curie Association, the Institute of Bota- ny, University of Bergen, the AHRC, and to the Depart- ment of Archaeology and the McDonald Institute, Uni- versity of Cambridge, for providing most of the funding necessary to the completion of this study. Special thanks go to Steve ROBERTS for his most constructive com- ments. We are also grateful to Goran DURN and three anonymous reviewers for their detailed remarks towards the improvement of this paper. 9. REFEREnCES ALLEN, J.R.M., BRANDT, U., BRAUER, A., HUBBERTEN, H.W., HUNTLEY, B., KELLER, J., KRAML, M., MAC- KENSEN, A., MINGRAM, J., NEGENDANK, J. F.W., NOWACZYK, N.R., OBERHANSLI, H., WATTS, W.A. & WULF, S. (1999): Rapid environmental changes in southern Europe during the last glacial period.– Nature, 400, 740–743. ANDRIČ, M. (2001): Transition to Farming and Human Impact on the Slovenian Landscape.– Unpubl. PhD The- sis, Universitiy of Oxford, 152 p. ANDRIČ, M. (2006): Prapoče pollen core and Holocene vegetation change in northern Istria.– In: MIRACLE, P.T. & FORENBAHER, Š. (eds.): Prehistoric Herders in Istria (Croatia): the Archaeology of Pupićina Cave. Archaeolo- gical Museum of Istria, 31–62, Pula. BALBO, A.L. (2005): The last days of a Mediterranean wet landscape. Human impact on and draining of shallow lake Arsa, Polje Čepić, Istria, Croatia.– 10th UNESCO Uni- versities Heritage Forum, Newcastle, 9 p.; http://www.ncl. ac.uk/unescolandscapes/files/BALBOAndrea%20Luca. pdf. BALBO, A.L. (2006): People and wetlands in the open karst of Istria, Croatia.– Newsletter of the Prehistoric Society, 52, 2–3. BALBO, A.L., KOMŠO, D. & MIRACLE, P.T. (2004) Geoar- chaeological survey of Polje Čepić and part of its hydrolo- gical basin (Istria Peninsula, Croatia): Report on the first field season.– Histria Archaeologica, 33, 265–276. BALBO, A.L., KOMŠO, D. & MIRACLE, P.T. (2006): Prehistory of the open karst, further discoveries from the geoarchaeological survey of Polje Čepić, Croatia.– Histria Archaeologica, 35, 33–42. BALBO, A.L., KOMŠO, D. & MIRACLE, P.T. (in press): Open-air Mesolithic settlements in a mutable karstic Mediterranean biotope. Polje Čepić (Istria, Croatia).– In: McCARTAN, S., WOODMAN, P., SCHULTING, R. & WARREN, G. (eds.): Mesolithic Horizons: Papers presen- ted at the Seventh International Conference on the Meso- lithic in Europe, Belfast 2005. Oxbow Books, Oxford. BARTLEIN, P.J. (2007): Time scales of climate change.– In: ELIAS, S. (ed.): Encyclopedia of Quaternary Science. Elsevier, Amsterdam, 1873–1883. BENNET, K.D. & WILLIS, K.J. (2002): Pollen.– In: SMOL, J.P., BIRKS, H.J. & LAST, W.M. (eds.): Tracking Envi- ronmental Changes Using Lake Sediments. Dodrecht, Kluwer Academic, 5–32. BERGLUND, B.E. & RALSKA-JASIEWICZOWA, M. (1986): Pollen analysis and pollen diagrams.– In: BERG- LUND, B.E. (ed.): Handbook of Holocene Paleoecology and Paleohydrology. New York, Chichester, John Wiley and Sons, 455–484. BEUG, H.-J. (1967): On the forest history of the Dalmatian coast.– Review of Palaeobotany and Palynology, 2, 271– 279. BEUG, H.-J. (1977): Vegetationsgeschichtlichte Untersu- chungen in Küstenbereiche von Istrien (Jugoslawien) (Research of vegetation development in coastal areas of Istria (Yugoslavia).– Flora, 166, 357–381. BJÖRCK, S. & WOHLFARTH, B. (2001): 14C Chronostrati- graphic techniques in paleolimnology.– In: LAST, W.M. & SMOL, J.P. (eds.): Tracking Environmental Change Using Lake Sediments. Dordrecht, Kluwer Academic Publishers, 205–245. BROUSOULIS, F., IOAKIM, C., KOLOVOS, G. & PAPANI- KOS, D. (1999): The Ioannina basin: geological and pala- eoenvironmental evolution in Quaternary and historical times.– In: BAILEY, G.N., ADAM, E., PANAGOPOU- LOU, E., PERLèS, C. & ZACHOS, K. (eds.): The Palae- olithic Archaeology of Greece and Adjacent Areas. British School at Athens, Athens, 87–96. 123Balbo et al.: Palaeoenvironmental and archaeological implications of a sediment core... CULIBERG, M. (1995): Dezertifikacija in reforestacija Slo- venskega krasa (Desertification and reforestation of the karst in Slovenia).– Poročilo o raziskovanju paleolitika, neolitika in eneolitika v Sloveniji, 22, 201–217. CULIBERG, M. (1997): Sermin: prazgodovinska in zgod- njerimska naselbina v severozahodni Istri (Sermin: a prehistoric and early Roman settlement in northwestern Istria).– In: HORVAT, J. (ed.): Paleovegetacijske razmere v Koprskem primorju. Opera Instituti archaeologici slove- niae ZRC SAZU, 3, 135–139, Ljubljana. DURN, G. (2003): Terra rossa in the Mediterranean region: parent materials, composition and origins.– Geologia Cro- atica, 56, 83–100. FLETCHER, W.J. (2002): Late-glacial and Holocene vegetati- on and prehistoric wood-use in the Istrian Karst, Croatia.– In: THIÉBAULT, S. (ed.): Charcoal Analysis. Methodo- logical Approaches, Palaeoecological Results and Wood Uses. 1st ed. Paris, BAR, 87–94. FLETCHER, W.J. & MADELLA, M. (2006): Characterising the Post-Mesolithic landscape at Pupićina peć: results of charcoal and phytolith analyses.– In: MIRACLE, P.T. & FORENBAHER, S. (eds.): Prehistoric Herders in Istria (Croatia): the Archaeology of Pupićina Cave. Archaeolo- gical Museum of Istria, Pula, 429–446. GEYH, M.A., SCHOTTERER, U. & GROSJEAN, M. (1998): Temporal changes of the 14C reservoir effect in lakes.– Radiocarbon, 40, Proceedings of the 16th International Radiocarbon Conference, 921–931. HERAK, M. (1991): Dinarides – mobilistic view of the gene- sis and structure.– Acta Geologica, 21, 35–117. JACOBSON, G.L.J. & BRADSHAW, R.H.W. (1981): The selection of sites for palaeovegetational studies.– Quater- nary Research, 16, 80–96. JAHNS, S. (2002): An improved time scale for the Holocene history of vegetation and environment on the South Dal- matian Island of Mljet.– Vegetation History and Archaeo- botany, 11, 315–316. JAHNS, S. & VAN DEN BOGAARD, C. (1998): New paly- nological and tephrostratigraphical investigations of two salt lagoons on the island of Mljet, South Dalmatia, Croa- tia.– Vegetation History and Archaeobotany, 7, 219–234. JENNINGS, J.N. (1971): Karst.– M.I.T. Press, Cambridge, Massachussets and London, England, 252 p. JENNINGS, J.N. (1985): Karst Geomorphology.– Blackwell Ltd, Oxford, Basil, 293 p. KELTS, K. & TALBOT, M.R. (1990): Lacustrine carbonates as geochemical archives of environmental change and biotic/abiotic interactions.– In: TILZER, M.M. & SER- RUYA, C. (eds.): Large Lakes. Ecological structure and functions. Springer-Verlag, London, 288–315. LAGO, L. & ROSSIT, C. (1981): Descriptio Histrie. La peni- sola istriana in alcuni momenti significativi della sua tra- dizione cartografica sino a tutto il secolo XVIII. Per una corologia storica (Descriptio Histrie. The Istrian peninsula in its cartographic tradition until the 18th century).– Trie- ste, Universita Popolare di Trieste. Edizioni Lint, 349 p. LAST, W.M. (2001): Textural analysis of lake sediments.– In: LAST, W.M. & SMOL, J.P. (eds.): Tracking Environmen- tal Change Using Lake Sediments. Kluwer Academic Publishers, Dordrecht, 41–81. LAWSON, I., FROGLEY, M., BRYANT, C., PREECE, R. & TZEDAKIS, P. (2004): The Lateglacial and Holocene environmental history of the Ioannina basin, North-west Greece.– Quaternary Science Reviews, 23, 1599–1625. LEROY, S.A.G. & COLMAN, S.M. (2001): Coring and dril- ling equipment and procedures for recovery of long lacu- strine sequences.– In: LAST, W.M. & SMOL, J.P. (eds.): Tracking Environmental Change Using Lake Sediments. Kluwer Academic Publishers, Dordrecht, 107–135. MACKERETH, F.J.H. (1966): Chemical investigation of lake sediments and their interpretation.– Proceedings of the Royal Society. Series B, Biological Sciences, 161. A dis- cussion on the Development of Habitats in the Post-Gla- cial, 295–309. MARCHESETTI, C. (1903): I castellieri preistorici di Trieste e della regione Giulia (Prehistoric hillforts of Trieste and the Giulia region).– Il Museo Civico di Storia Naturale, Trieste, 206 p. MIHLJEVIĆ, D. (1998): Relief of structural origin and the structural–geomorphological regions of the Istria and Kvarner.– Proc. Natural History Researches of the Rijeka Region, 23, 277–302. MIKO, S. & MESIĆ, S. (2004): Geochemical record of Holo- cene land use change and anthopogenic Pb deposition in a Northern Adriatic karst lake (Lake Vrana, Cres Island). – 32nd International Geological Congress, Abstracts, Flo- rence, 35. MIKO, S., MESIĆ, S., FORENBAHER, S. & BELAK, M. (2005): Archeometric analysis of Bronze Age potsherds from Vrana Lake (Cres Island): a study of provenance and dating of slope processes.– Abstracts Book of 3rd Cro- atian Geological Congress, Opatija, 99–100. MIRACLE, P.T. & FORENBAHER, S. (2005): Neolithic and Bronze Age herders of Pupićina Cave, Croatia.– Journal of Field Archaeology, 30, 255–281. MIRACLE, P.T. & FORENBAHER, S. (eds.) (2006): Pre- historic herders in Istria (Croatia): the Archaeology of Pupićina Cave, Pula. Archaeological Museum of Istria, Pula, 542 p. MOORE, P.D., WEBB, J.A. & COLLINSON, M.E. (1991): Pollen Analysis.– Blackwell Science, Oxford, 216 p. NELSON, D.W. & SOMMERS, L.E. (1996): Total carbon, organic carbon, and organic matter.– In: BIGHAM, J.M. (ed.): Methods of Soil Analysis: Part 3 Chemical Methods. Madison, Soil Science Society of America, 961–1010. NOWACZYK, N.R. (2001): Logging of magnetic suscepti- bility.– In: LAST, W.M. & SMOL, J.P. (eds.): Tracking Environmental Change Using Lake Sediments. Kluwer Academic Publishers, Dordrecht, 155–170. OLDFIELD, F., ASIOLI, A., ACCORSI, C.A., MERCURI, A.M., JUGGINS, S., LANGONE, L., ROLPH, T., TRIN- CARDI, F., WOLFF, G., GIBBS, Z., VIGLIOTTI, L., FRIGNANI, M., VAN DER POST, K. & BRANCH, N. (2003): A high resolution late Holocene palaeoenviron- mental record from the central Adriatic sea.– Quaternary Science Reviews, 22, 319–342. 124 Geologia Croatica 59/2 O’SULLIVAN, P.E. (2004): Palaeolimnology.– In: O’SULLI- VAN, P.E. & REYNOLDS, C.S. (eds.): The Lakes Hand- book: Limnology and Limnetic Ecology. Blackwell Publi- shing, Malden, Oxford, Carlton, 609–666. PARENZAN, P. (1928): Il Lago d’Arsa (The Arsa Lake).– Histria Nobilissima, 1, 47–51. PETRIĆ, N. (1979): Introduzione alla preistoria dell’Istria (Introduction to the Prehistory of Istria).– Atti, 9, 185– 248. REILLE, M. (1992): Pollen et spores d’Europe et d’Afrique du nord (European and north African pollen and spores).– Laboratoire de Botanique Historique et Palynologie URA CNRS, Marseille, 520 p. REILLE, M. (1995) Pollen et spores d’Europe et d’Afrique du nord (Supplement) (European and north African pol- len and spores).– Laboratoire de Botanique Historique et Palynologie. URA CNRS, Marseille, 327 p. ROGLIĆ, J. (1950): Čepićko Polje (Polje Čepić).– Geografski glasnik, 11–12, 147–148. SANDGREN, P. & SNOWBALL, I. (2001): Application of mineral magnetic techniques to palaeolimnology.– In: LAST, W.M. & SMOL, J.P. (eds.): Tracking Environ- mental Change Using Lake Sediments. Kluwer Academic Publishers, Dordrecht, 217–237. SANGIORGI, F., CAPOTONDI, L., COMBOURIEU NEBO- UT, N., VIGLIOTTI, L., BRINKHUIS, H., GIUNTA, S., LOTTER, A.F., MORIGI, C., NEGRI, A. & REICHART, G.-J. (2003): Holocene seasonal sea-surface temperature variations in the southern Adriatic Sea inferred from a multiproxy approach.– Journal of Quaternary Science, 18, 723–732. SCHMIDT, R., MULLER, J., DRESHER-SCHNEIDER, R., KRISAI, R., SZEROCZYNSKA, K. & BARIĆ, A. (2000): Changes in lake level and trophy at Lake Vrana, a large karstic lake on the Island of Cres (Croatia), with respect to palaeoclimate and anthropogenic impacts duri- ng the last approx. 16,000 years.– Journal of Limnology, 59, 113–130. ŠIKIĆ, D. & POLŠAK, A. (1973): Osnovna geološka kar- ta (OGK) SFRJ 1:100000, Tumač za list LABIN (Basic Geological Map of SFRY 1:100000, Geology of the Labin Sheet).– Institut za geološka istraživanja Zagreb (1963), Savezni geološki zavod, Beograd, 55 p. ŠKORIĆ, A., MAYER, B., VRANKOVIĆ, A. & BAŠIĆ, F. (1987): Pedološka karta Istre (Soil Map of Istria).– Insti- tute for Pedology at the Faculty of Agriculture, University of Zagreb, 1st ed. Zagreb. STOCKMARR, J. (1971): Tablets with spores used in absolu- te pollen analysis.– Pollen et Spores, 13, 615–621. STUIVER, M. & REIMER, P. (1993): Extended 14C databa- se and revised CALIB radiocarbon calibration program.– Radiocarbon, 35, 215–230. STUIVER, M., REIMER, P.J. & REIMER, R.W. (2005): CALIB 5.0.– http://calib.qub.ac.uk WHITLOCK, C. & LARSEN, C. (2001): Charcoal as a fire proxy.– In: SMOL, J.P., BIRKS, H.J.B. & LAST, W.M. (eds.): Tracking Environmental Change Using Lake Sedi- ments. Kluwer Academic Publishers, Dordrecht, 75–97. WULF, S., KRAML, M., BRAUER, A., KELLER, J. & NEG- ENDANK, J.F.W. (2004): Tephrochronology of the 100 ka lacustrine sediment record of Lago Grande di Monticchio (southern Italy).– Quaternary International, 122, 7–30. WUNSAM, S., SCHMIDT, R. & MULLER, J. (1999): Holo- cene lake development of two Dalmatian lagoons (Malo and Veliko Jezero, Isle of Mljet) in respect to changes in Adriatic sea level and climate.– Palaeogeography, Palaeo- climatology, Palaeoecology, 146, 251–281. Manuscript received March 17, 2006. Revised manuscript accepted November 24, 2006.