I GEOL. CROAT. I 50/2 12S[ - 260 [0 Figs. ZAG REB [997 Tectonic Structures Along the Periadriatic Lineament in Slovenia Pero MIOC Key words: Pcriadriatic lineament , Karavankc, Tecto­ nic st ruc tu re, Zone of Periadriatic lineament, ol1h­ ern Karavankc thrust, Velunja thnlst, Olsev3-Kosuta thrust, Southern Karavanke thrust. Abstract The Pcriadriatic lineament extends from the Sesia zone in Italy across southern Austria into Slovenia, in (he area of the Kara vanke mounlains. II co ntinues eastwards into the Pannonian basin in Hun ­ gary as [he l3alalon linc. The Karavanke mountain range run s from Slovenia in the cast wcslw,Lrds into the Carnian Alps of Austria. Fur­ ther cast Ihey ex tend beneath [he Tert iary sediments of the Pannonian basin in lO Ilungary. The Karavan kc mountains represent a boundary zone between the Eastern Alps to the north and the Jul ian and Savi­ nja-Kamnik Alps or Southern Alps to the south. The Periadriatic line­ ament interseCTs The eaSTern pan of the Kar--~ \ ~ -. .~ '. / ( o • • UOINE I Fig. 2 The geographic position of the Karavankc Mountains. Mioe: Tectonic StrUCl\Jres Along thc Pcriadriatic Lincament in Slovenia .l.. / ) -.Ii ~ -« A ( J50 U s __ J50 --­ '- 253 \ '- '-/ / --­ '- \ o l- O UUBUANA .......... I ,. -, .... I I -. --- '- / '- '- ZAGREB o Fig. 3 A generalised tectonic map of the Karavanke Mts. with [he bound.ary tectonic un its of the Eastern Alps, Julian-Savi nja Alps and Panon­ nian basin . Legend: JSO) Julian-Savinja units; SKO) South Karavanke overthrust: O K) OlSeva-KosUla overthrust; PL) Peri adriatic linea­ men t; ZPL) Zone of Periadriatic lineamenl ; NKO) North Karavanke overthru st; MA) Middle Austroalpine; UA) Upper Austroalpine; T ) Tonalite of Pohotje; B) Neogene basins; PO ) Pannonian basin; 1) Lavantal fault; 2) Sava fault; 3) LjulOmer fault ; 4) Ruba fault. ied by MIOe (1978,1983) and MIOC & ZNJDARCIC ( 1983) for the Sloyenj Gradee and Rayne sheets. The most eas te rn extension of the Karavanke moumains, reaching into the Haloze area, was studied by ANICIC & JURISA ( 1985) for the Rogatee shcet. These authors prepared geological maps and reviews of the geological structure of the studied areas. The Peri adriatic lineament runs along the Kara­ vanke mountains and divides them into the Northern and Southern Karav'lI1ke. Near the system of faults , running along the lineament, there is an uplifted part of the metamorphic basement with granite and tonalite. Rece ntly these rocks represent a zone dividing the Karavankc mountains into three parts . From north - south , these are: the Northern Karavanke, the Periadri­ at ie lineament (ANGENHEISTER & BOGEL, 1972) or zone of the Periadriat ic seam (MIOC, 1983, 1984, 1986) and the Southern Karavanke. In the western part of the Slovcnian Karavanke mountains, between Jese­ nice to the west and OlSeva to the east, only the South­ ern Karavanke Mts. occur reaching into Slovenia. From Olseya to the south to Peea to the north all the parts of the Karavanke mountains extcnd into Slovenia (Figs. 2 & 3). 2. STRATIGRAPHY Subdivi sion of the Karavanke mountains into three parts was made according to lithological and stra tigra­ phic charac teri stics as well as the tectonic structure of the single units. To facilitate correlation of the geologi­ cal development with the neighbouring areas of the Karavanke mountains, we represent accretionary dia- grams for the complete Eastern and Southern Alps (Fig. 4). The Northern Karavanke are formed from Si luro­ Devonian, Permo-Triassic and Jurassic rocks. The Si l­ uro-Devonian beds are composed of phylliloidic slates with single plates of diabase in between. These bcds are known as the Magdalensberg Series (RIEHL·HER· WIRSCH, 1970). The Permo-Triass ic clastic sedimentary rocks unconfonnably overlie the Lower Palaeozoic slates and phyllites of the consol idated pre·Alpine basement. The· se sediments are represented by redd ish sandstones and conglome rates of the "Yeruccano"-type, which orig i­ nated from weathering of the surrounding metamorphic rocks, and to a lesser extent acid volcanic rocks . They are conformably overlain by the Lower Triass ic clastic carbonate rocks. In the Triassic (Scithian) Series there are sandstonc, shale and bedded limestone. Dolom ite as well as thin bedded limestone of the Anisian follow. The Ladini an is represented by clayey marl beds in the lower part (Pannas beds) with crystalline limestone and dolomite known as the Wetterstein beds on top of them. Marl s and limestones occur in the Carnian sequence and are followed by the Norian·Rhaetian beds - Main Dolomite (Hauptdolomit) and Dachstein limestone. Bedded lime· stones with cherts and clayey marl sediments belong to the Jurass ic, although these Mesozoic rocks extend from the Lias to the Lower Cretaceous. The Jurassic sediments in the lower parts of litho­ logically heterogeneous sequences are formed from limestone breccias, which are overlain by reddish to greenish platy micritic limestones, which contain cla­ yey mixtures and grade into calci te shales (RAMOYS MAJOR SLOVEN IAN PART OF THE EASTERN AND rT::E~~~RA~N:.:E:,:Si~[SBO~U~T~HERN ALPS SUPERTERRANE ":0 ZZ(I) QO ..... !:: ..... z 00::J <2~ >- TERTIARY CRETACEOUS JURASSIC TRIASSIC CARBONI­ FEROUS DEVONIAN ORDO­ VICIAN ZOIC Legend: 1. ( 4 R B ~ 12 I> ~>I 16 ~ 1 1b 2 3 ...;...- 0 D . . 5 6 7 El D .' 0"'-' 0 o • 9 10 11 ~ ' . -. w 0 13 14 15 1+ + ++1 - ~ Fig. 4 Accretionary cliagnuns of (he Eastern and Southern Alps in Slovenia. Legend: I a) facies change; I b) ullcorronn ity; 2) tillites; 3) continental clastics; 4) rcd beds . Marine cnviroments: 5) pcl ites: 6) arenites; 7) conglomerates: 8) pelagic carbonates; 9) shallow waler carbonates. Volcanic rocks: 10) fe lsic: 11) mafic; 12) inlennediatc: 13) plutonic rocks: 14) ophiol it ic sequence: 15) ages: K = K-Ar: R = Rb-Sr: 16) post-accretionary thrust. & REBEK, 1970), These sed iments are interlayered with radiolarian cherts . This basinal sequence was deposited during the Lias, Dogger, Maim and Berri­ asian-Valanginian as indicated by characterist ic fossils (MIOC & SRIBAR, 1975), The limestone radiolarite sequence was also thrusted from the south over the lithological units of the Northern Karavanke. Based on lithological correlation , it can be assumed that thi s sequence was deposited in the northern, distal parts of Tethys, The Zone of Periadriatic lineamelll runs along the nOrlhern contact of the Periadriatic lineame nt and extends from Austria int o Slovenia near Crna east­ wards, and wedges out along the faults, north-cast from Velcnje, continuing as a fault into the Pannonian basin. The mentioned zone is up to 43 km in length in Slove­ nia and up 10 3,5 km wide (STRUCL, 1970). The zone consists of a gran ite belt jn the north , a metamorphic belt in the central part and a tonalite belt in the south. The gran ite belt on the northern s ide is in tectonic contact with rocks of th e Magdalcnsberg Series, and on the southern side in primalY contact with the metamorphic belt. Along thi s primary con tact, the neighbouring rocks were incorporated into a graniti c magma thus forming intrusive magmatites, (agmatites and ve nites), in the boundary part of the granite and cordierite schists (slates) and appear near the contact in the metamorphic belt (Fig. 5). However, many varieties of granite exis t in the granite belt , ranging [rom fine grained, medium grained to porphyritic granite. In some pans, e.g. Cofati hill , the granite grades into g ranitoid , and in some places to diorite. The beginning of the Alpine Orogeny was charac­ terized by intense rifting, which resulted in strong mag­ matic act ivity. In the initial phase there was a granite intrusion. Relics of granite . formed at that t ime, arc today found along the Periadriatic lineament. Numerous authors have published papers on the granite. including EXNER (1973,1976), FANINGER & STRUCL ( 1970), MIOC (1983, 1984) and others, Isotope analysis or Ihe granite gave Ihe following resulls: K-A r ~ 245-210 Ma, U-Pb ~ 230 Ma and Rb-Sr ~ 224-216 Ma (CLIFF el aI. , 1974; SCHARBERT, 1975), accordi ng wh ich Ihe gran­ ite and the gran ite intrusion, respectively, are or Upper Permian - Triassic age. In the metamorphic belt there arc phyllites (Ordovi­ cian-Si luri an), amphiboli tes and gneisses, whi ch are considerably o lder. In the Upper Oligocenc the tonalite mass if originated (K-A r and Rb-Sr 30-28 Ma, SCHAR­ BERT, 1975), Tile Southern Kara vGflke consists of the Devonian , Carboniferous, Permian, Triass ic, Jurassic and Tertiary sediments. In the Lower Devonian there is bedded Iimc­ stone, overlain in part by reddi sh breccia. The Middle Devonian reef limestone with corals and hydrozoa fol ­ lows and in the Upper Devonian there are beddcd lime­ stones and shales. The Lower Carboniferou s developed as a n ysch sequence. This includes shales, graywacke, olistostro­ me brcccia, quartz conglomerates and single beds of dark limestone. Appearances of quartz porphyry and tuff are also characteristic. The molassc sedimentation began in the Upper Carboniferous, and is represented Mioc: Tectonic Strucltlrc.~ Along the Pcri:ldri:uic LinealllCtll in Slovenia I , ,w ---> eOFATIJEV MOUNT (1314 m.J c . 2,5 • 3 km , I Fig. 5 Schemalic cross·scct ion of the Ka ra vanke·granite zone by e rna. Legcnd: I) gran ite; 2) porphyroid·gran ite; 3) enclaves of Ihe gneiss, amphi bolite and diabase; 4) gneiss and phyllites; 5) Magdalensbcrg series (greenish states intruded by diabase sitt s); 6) kornites; 7) tonalite. by quartz sand stones and conglomerates as well as shales with si ngle beds of limestone containing mi cro and macro faunal remains. In the Lower Permi an there are Trogkofel organo­ gen ic limestones, shales, sandstones and co ng lomer­ ates. Trbiz breccia and Groden clastic layers lie above these beds. The Neoschwagcrina limestone is a strati­ graphic equi valent of the mentioned Groden layers. In the Upper Permian there are grey limestones with fossil fauna and dolomite. The age of the Palaeozoic, Carboniferous and Per­ mian sediments has been proven with numerous fossils studied by Ramovs and partly Kochansky-Devide. The foss il fauna has been cited by BUSER (1980) and MI- 0C': (1978, 1983, 1984). The Triassic begins with yellowish dolomite lying on the Uppcr Permian beds. It is fo llowed by shales, shaly marls, sandstones and single horizons of bedded limestones. In the Middle Triassic (Anisian) there is bedded dolomite, single horizons of bedded limestones which continue into the Ladinian. Beds of marl and vol­ cani c rocks (keratophyres and tuff) appear in the Ladi­ nian , as well as bedded limestones and dolomites. The Upper Triassic - Carnian is represented by limestones, do lom ites and marls, while for the Norian-Rhaetian Main Dolom ite and Dachstein limestone are most char­ acteris tic. The Jurassic is represe nted by bedded limestones with cherts and redd ish marl. The lithological develop­ ment of these beds is similar to that in the Northern Karavanke. and it is assumed that they originate from the same marine basin. The Eocene limestones are the oldest Tertiary sedi­ ments of the Karavanke mountains. They appear as ero­ sional remnants on the Upper Triass ic deposits. Some of the clastites (marls), which overlie these limestones and are inc luded into the Oli gocene, are in fact of Eocene age. In the Upper Oligocene there are breccias, sand­ stones and marl s and characteristic andesite tuff. The 255 tuff is most abundant in the eastern part of the Southern Karavanke. Beside the tuff there are also volcanic brec­ cias and " outflows" or s in gle beds of andes it e. The mentioned vulcanites are also known as the Smrekovec Series (MIOC': , 1983) . These sediment s continue towards the east into the area of Hrva tsko Zagorje (S IM UNIC & PAMIC, 1993) and further into the Pan­ nonian basi n. The Neogene sediments surround the Northern Kar­ avanke and the eastern part s of the Southern Kara­ vanke. Thcy are represented by clastic sediments which strati graphically range from the Ounangian to Pli ocene. The Quarternary sediment s inEIl river valleys and cover the slopes of the Alps. The most in tercsti ng arc the glac ial sediments, especially moraines being pre­ served at three different altitudes. 3. TECTONICS The geotectonic posit ion and correspond ing geolo­ gical and tectonic composition of the Karavanke moun­ ta ins have intrigued many researchers. Numerous au th­ ors (WINKLER, 1924; KAHLER, 1953), have discus­ sed the tectonics of the Karavanke Mountain s, incl u­ ding RAKOVEC (195 6) who assumed that the Kosuta thrust was shifted northwards. The same thru st was mentioned by BUSER (1980) who interpre ts it to be shifted southwards . ANDERLE ( 1970) di scovered, while researching the Austrian part of the Western Karavanke, that the tectonic units in thi s part were thrust towards the north. STRUC L ( 1970) wrote about the tec tonics of the No nhern Karavanke in Slove ni a and also mentioned the thrust of the Northern Kara­ yanke. SIKOSEK (1971) defined the Karavanke mountains geoteetonically as the Alpine-Dinaride boundary zonc. HERAK ( 1986) included the Karavanke mountains together with the Julian and Savinja Alps into the Supradinaricum. According to the resul ts of the latest geo log ical investigations, the Northern and Southern Karavanke were cach divided into two tectonic units, between which lies the Periadriatic zone and Periad riatic linea­ ment , respectively. In the Northern Karavankc these are the Northern Karavan ke th rust and the Velunja thrust (MIOC':, 1978, 1983, 1984). T hey are foll owed by the Peri adriatic lineament and after that the OlSeva-Kosuta thrust and the Southern Karavanke thrust. The Northern Karavallke thrust (Fig. 6) consists of the Middle and Upper Triassic deposits with the Juras­ sic layers caught between them. This unit is thrusted northwards over the Tertiary sediments of the Mezica­ Vitanje tectonic ditch. A single tectonic kl ippen of thi s thrust has been preserved on metamorphic rocks in the area of Strojna, and on Ostri vrh (Sveti Duh) of Koban­ sko. The tcctonic klippen shows the former size of thi s thru st which lat er di sintegrated and was to a large extent eroded. NE ~ ZONE OF VELUNJA S. A'LPS *,.J>E'RlAOR'AT .. L* THR. ¥- ZONE OF THE NORTH KARAVANKE SCALES EASTEREN ALPS Rayne (400 m) )1 Fig.6 Schematic cross-section of the Northern Kuruvanke. from the Pcriadrialic zone of the south to the Eastern Alps of the north. Legend: I) gneiss; 2) phyllites: 3) Miocene deposits: 4) Upper Triassic dolomite: 5) Jurassic deposits; 6) Middle Triassic-Wetterslein limestones ~lfld dolomites: 7) Karnian layers; 8) Lower Triass ic deposits: 9) Magdalensberg series: 10) granites (G), metamorphic rocks (M), tonalites (T). Single parts of the thrust were stackcd over each other along reverse faults during later tectonic activity. These slacks represent an entire thrust or Triassic beds and Jurassic pclagic sediments which were all thrusted over the metamorphic basement of the Eastern Alps. Five s ingle stacks were estimated within the frame of the Northern Karavanke thrust. Thrusting over the CIYS­ talline rocks north of the present Karavanke mountain area had already taken place in the Upper Cretaceous. Later thrusting over the Neogene sediments occurred somewhere at the end of the Neogene at the timc when the Alps were uplifting, indicating a gravitat ional com­ ponent to this thrusting. The Veltmja thrust (named after the river Velunja) was thrusted northwards on to the Triassic deposits of the Northern Karavanke thrust. From the southern side, the granite of the Periadriatic zone has been thrusted over the Velunja thrust along a revcrse fault. The com­ position of this tectonic unit includes old Palaeozoic s lates of the Magdalensberg Series whieh dip so uth­ wards under the granite. The Periadrialic lineament extends from Austria into Slovenia as the Periadriatic zone. The zone is bounded by two reverse faults and it plunges south­ wards. The reverse faults are the Cofatia faulL on thc north and the Periadriatic lineament , loca lly named Smrekovee fault, on the south (Figs. 5-7). The zone extends eastwards to Paski Kozjak where it wedges out and runs as a lineament towards the south-eastern PohOIje. The eastcrn extension of the Periadriatie linea­ ment is cut by the Labat faull, which runs in a NW-SE direction along the so uth -wes tern Pohorje, where the extension of the Lineamen t is shifted towards south­ east. The eastern and north-eastern extension continues along the Dravinja river, then along the Drava valley, south from Ormoz, and further towards Cakovec, exte­ nds into the Panonnian Basin and runs towards Balaton in Hungary. The geological composition of the Periadriatic zone includes a granite belt , metamorphic and tonalite belts. This zone represents a part of the continental c ru st, which was cut along a fault and after horizontal-vertical movement reached the surface. Structural clements, including foliation and lineation in the metam orph ic belt, are parallel to the Lineament, and the foliation dips steeply (70 - 90°) towards the sout h. The parallel lin­ eation dips towards the west and south-west (60 - 80°), which proves horizontal-vertical movements along thc Lineament. Generally, the Periadriatic lineament represents the tectonic boundary between the Eastern Alps in the nor­ th and the Southern Alps (Julian Alps and Karavanke mountains in Slovenia). Single parts of the lineament have loca l names, c.g. the Canavese line, Insubrie line, Guidicaric line, Pususte ria line, Gail line, Smrekovcc line, and in Hungary the Balaton line (Fig. 1). Tile Ol§eva-KosUIG overthru st extends rrom the Austrian border in the west, via Kosuta, OlScva, Boc and Haloze, respectively, towards the east into the base­ ment or the Pannonian basin. It consists most ly of the Upper Triassic deposits and to a lesser extent, of the Jurassic deep marine sediments. In the eastern part, in the area of OlSeva, this unit bounds to the north to the Peri adriatic lineament and dips towards the south (reverse fault), under the SOllthern Karavankc thru st. The contacts of these two units are clearly visible espe­ cially on the southern slopes of Olseva (Fig. 7), where the Upper Carboniferous beds of the Southern Kara- Mine: Tectonic Structures Along thc Periadri~ltic Lineament ill Slovelli;1 257 ---------------------------------------------- Fig. 7 The lec(Qnic contact of the Olseva-Kosuw unit with (he Southern Karavanke unit Oil the southern slopes ot Olseva. Legend: CP) Upper Carboniferous - Permian beds (of the Southern Karavanke thrust); T) the Upper Triassic dolomites (milonitised) of the Olseva-Kosuta unit. vanke thrust overthrust the Upper Triassic sediments (Main Dolomite) of the Olscva-Kosuta unit. The Juras­ sic sediments arc usually trapped between the Triassic sediments. The Southern Karavanke overthrust (Fig. 8) consists of the Devonian, Carboniferous, Permian and Triassic beds. The structural elements have, in general, southern vergence. In isolated places, the beds are folded and single parts of the unit disintegrated into numerous smaller parts. The general position of this tectonic unit as a whole also verges towards the south. In the western part or the Southern Karavanke it dips under the Julian Alps and in the eastern part of the Southern Karavankc under the Savinja Alps. 4. DISCUSSION The state of the single tectonic units, in the area directly adjacent to the Peri adriatic lineament, is con­ siderably different from the structural state of the tec­ tonic units regionally, e.g. in the Sloven ian part of the Eastern Alps and in the Julian and Savinje Alps. Tec­ tonic klippen of the Northern Karavanke, thrust on the N -----7 __ * _ - - ~ ZONE OF 0(---- SOUTH KARAVANKE THRUST oJ!< OLSEVA - KOSUTA THR.------,.,..-- PERIADRIATIC L. SAVINJA (660 m.) ~ II c. 6 km , I Fig. 8 Schematic cross­ section of the South­ ern Karavankc Mts. from the Peri adriatic lineament to the Savi­ nja river. Legend: I) Permo-Carbon iferous layers: 2) Triassic sed­ iments: 3) Upper Tri­ assic dolomites (Main Dolomite) and Dach­ stein limestones: 4) to­ nalite; 5) Quaternary rock -fall breccia: PL) Peri adriatic lineament. l..JCOlogm CrOallCn ':JUfl. ~sw NE~ ~ SOUTHERN ALPS -+ EASTERN ALPS Fig. 9 Schematic cross­ section between Ko­ zjak and tbe Savi ­ nja Alps. Lege nd: I<- SAVINJA ALPS * KARAVANKE -* fSOUTH+ NORTH 1 POHORJE ~ KOZJAK SA) Savinja Alps (overthrust): S KO) Southern Karavan ­ ke thrust; OK) Ols­ eva-Kos uta thrust; PL) Zone of th e Peri adriati c linea­ ment; YO) Yclunja thrust: NKO) Nor­ th Karavankc thru­ st; Te) Tertiary de­ posits: MA) Mid ­ dle A ust roa lpine: o 10 20 30 km VA) Uppcr Aus­ troalpine; Tn) ton ­ alitc. 'L-~ __ ~' __ ~ ___ 'L-~ __ -"' metamorphic comp lex has a subh orizontal position, while tectonic un its ncar the Peri adriatic lineament are subvert ical (Fig. 9). The force producing these thrusts, as far as we know, was provided by the movement and collision of two "microplates" - the Adriatic (Apulian) and the Eas­ tern Alps (Austroalpini c) microplate in the Uppcr Cre­ taceous and the Tertiary. Due to the movement o f the Adriat ic plate towards north, the thrust of the Southern Alps appeared in the same dirccti on (FRISCH, 1978), and their thrust over the Eastern Alps (Ostalpi num) in the Upper Cretaceous. At that time, single Ihrusts con­ sisting of the Lower Palaeozoic slates, (e.g. the Strojna and Remsnik thrust) were sh ifted in the Sioveni an part of the Eastern Alps, as well as the Northern Karavanke th rust (of the Triass ic-Ju rass ic sed iments) whi ch was thrusted over the Lower Palaeozoic rocks. Collision of the microplates also caused disintegra­ tion of the southern margi n of the Eastern Alps plate. Classical thrusting stopped, but the continental crust was dislocated and the horizontal-vertical (transcurrent) movements of th e sin gle blocks appeared along the mentioned fault s. Si ngle blocks from the basement dis~ integ rated the above laying sediment complexes and some parts, like the Pcriadriatic zone, came to the sur­ face (Fig. 10). The horizonta l movements are especially dist inctive along the Periadriatic lineament, where large facies dif­ ferences of the same strat igraphi c units, recently lying north and south of th e Periadriatic lineament can be seen. For example, the Permo-Triassic was deposited in the area of the Easte rn Alps in a form of con tinental clastic formati ons, whereas South of the Periadriatic lineament the Permian and Triassic fo rm a marine development. In Lombard ia sim ilar Permo-Triassic sed­ iments lie south of the Peri adriatic lineament and have the same mineralogical composition as those in Austria and Slovenia. On the basis of this, we can conclude that these sediments formed a cohesive regiona l sedimenta­ ry unit. The Triassic and Jurassic sediments on Kosuta, included into Kosuta-OlSeva tectonic unit , were once the same tectonic unit with the corresponding layers of the Northern Karavanke thrust. It can be concluded that the Periadriatic lineament was ac ti ve after overthrusting of the Northern Kara­ vanke thrust. The Pcriadriatic zone reached the surface during or after the Miocene, as shown by the inclusions of tonalite fro m the Karavanke mountains in the gran­ ites of the Ottnangian - Karpathian sediments (M 10C, 1978). With continuing approach of the Adriat ic and Aus­ lroalpinic micro-plales, subduClioll of the Eastern Alps mi cro-plate and anatexa of il s active southern margin occurred. A granitoidic magma was produced as a con­ sequence of these processes. It seems that mafic magma was partially contaminated by continental crust in the southern part of the subduct ion and ana texic zones, respectively. The result o f this mixing was thc Kara­ vanke tonalite enriched with hornb lende. The same magma gave rise to the intense andes itic volcan ism. In the Upper Oligocene, a sialic island ridge wit h a system of volcanoes, which can be traced through the whole of Sloveni a from Jesenice to Rogaska Slatina, whe re it crosses to Croatia, was formed along the northern mar­ g in of the Southern Karavanke. South of this ridge, a bas in was formed in which sed imentary-volcanogeni c material was deposited (MIOC et aI. , 1986). Deposition proceeded from the northern margin area into the basin by mudflows, as reflected in the sedimentary tex tures developed. In the northern part of the basin th ere are coarse to fine grained sediments (from breccia to pelite) with graded bedding, while in the southern part there are mostly laminated layers of turbiditic character. This complex of volcanogenic sediments is called the Smre­ kovec Series and reaches a th ickness of approx imately 1,000 m (MIOC, 1983). Northwards, in the area of Pohorje, granitoidic mag­ ma havi ng textural characteri stics of tonalite con tains mostly biotite instead of hornblende as a characteristic mineral. Dacite appears as its effu sive equ ivalent. It Mioe: TeClOnic StrucllIres Along the Periadriatic Lincamcnt in Slovenia 259 ---------------------------------- SA? Fig. 10 Schematic block-diagrams of the Karav