Sediment infill of the Middle Triassic half-graben below Mt. Vernar in the Julian Alps, Slovenia

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Luka Gale
Katarina Kadivec
Marko Vrabec
Bogomir Celarc†


A sediment infill of a small, late Anisian–earliest Ladinian half-graben, sealed by massive limestone of the Schlern Formation is exposed on the northeastern slopes of Mt. Vernar in the eastern Julian Alps, Slovenia. The pre-rift base of the succession is formed by a chaotic mixture of massive limestone and limestone breccia of the Anisian platform. Sedimentation in the half-graben started with a 20 m thick thinly bedded pink nodular limestone which is informally named here as the Vernar member. It consists of microbial carbonate and was probably deposited within the photic zone. The Vernar member is overlain by poorly sorted polymict breccias of the Uggowitz Breccia Formation which reaches a thickness of at least 150 m, but pinches out rapidly towards the SE graben margin, reflecting the highly asymmetric basin geometry. Individual beds of breccia represent successive debris flow deposits. The Uggowitz Breccia Formation is followed by a few metres of sandstone and sandy limestone of the Buchenstein Formation. The limestone contains abundant grains of shallow marine  origin and terrestrial plant fragments. The overlying post-rift Schlern Formation consists of crudely bedded and massive limestone, covering the graben. The consistent NE-SW strike of the graben-bounding faults and of the smallscale conjugate normal faults observed in the Uggowitz Breccia Formation suggests that the half-graben originated from NW-SE directed extension.


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BALINI, M, JURKOVŠEK, B. & KOLAR-JURKOVŠEK, T. (2006): New Ladinian ammonoids from Mt. Svilaja (External Dinarides, Croatia).– Riv. Ital. Palaeont. Stat., 112, 383–395. doi: 10.13130/2039-4942/6348

BERRA, F. & CARMINATI, E. (2010): Subsidence history from a backstripping analysis of the Permo-Mesozoic succession of the Central Suthern Alps (northern Italy).− Basin Res., 22, 952–975. doi: 10.1111/j.1365-2117.2009.00453.x

BOSELLINI, A., GIANOLLA, P. & STEFANI, M. (2003): Geology of the Dolomites.− Episodes, 26, 181–185. doi: 10.18814/epiiugs/2003/v26i3/005

BUDAI, T. & VÖRÖS, A. (2006): Middle Triassic platform and basin evolution of the Southern Bakony Mountains (Transdanubian Range, Hungary).− Riv. It. Palaeont. Strat., 112, 359–371. doi: 10.13130/2039-4942/6346

BUSER, S. (1989): Development of the Dinaric and the Julian carbonate platforms and of the intermediate Slovenian Basin (NW Yugoslavia).− Boll. Soc. Geol. Ital., 40, 313–320.

BUSER, S., KOLAR-JURKOVŠEK, T. & JURKOVŠEK, B. (2008): The Slovenian Basin during the Triassic in the light of conodont data.− Boll. Soc. Geol. Ital., 127, 257–263.

CAPUTO, R., POLI, M.E. & ZANFERRARI, A. (2010): Neogene–Quaternary tectonic stratigraphy of the eastern Southern Alps, NE Italy.− J. Struct. Geol., 32, 1009– 1027. doi: 10.1016/j.jsg.2010.06.004

CASTELLARIN, A. & CANTELLI, L. (2000): Neo-Alpine evolution of the Southern Eastern Alps.− J. Geodyn., 30, 251–274. doi: 10.1016/S0264-3707(99)00036-8

CELARC, B., GORIČAN, Š. & KOLAR-JURKOVŠEK, T. (2013): Middle Triassic carbonate-platform break-up and formation of small-scale half-grabens (Julian and Kamnik-Savinja Alps, Slovenia).− Facies, 59, 583–610. doi: 10.1007/s10347-012-0326-0

DUNHAM, R.J. (1962): Classification of carbonate rocks according to depositional texture.– In: HAN, W.E. (ed.): Classification of carbonate rocks, A symposium. Amer. Ass. Petrol. Geol Mem., 108–121. doi: 10.1306/M1357

EMBRY, A.F. & KLOVAN, J.E. (1971): A late Devonian reef tract on northeastern Banks Island.− NWT Bull. Can. Petrol. Geol., 19, 730–781.

FARABEGOLI, E. & LEVANTI, D. (1982): Triassic stratigraphy and microfacies of the Monte Pleros (Western Carnia, Italy).– Facies, 6, 37–58.

FARABEGOLI, E., JADOUL, F. & MARTINES, M. (1985): Stratigrafia e Palaeogeografia anisiche delle Alpi Giulie occidentali (Alpi Meridionali – Italia).− Riv. It. Palaeont. Strat., 91, 147–196.

GAWLICK, H.-J., GORIČAN, Š., MISSONI, S. & LEIN, R. (2012): Late Anisian platform drowning and radiolarite deposition as a consequence of the opening of the Neotethys ocean (High Karst nappe, Montenegro).− Bull. Soc. géol. France, 183, 349–358. doi: 10.2113/gssgfbull.183.4.349

GIANOLLA, P., DE ZANCHE, V. & MIETTO, P. (1998): Triassic sequence stratigraphy in the Southern Alps (Northern Italy): definition of sequences and basin evolution.− In: DE GRACIANSKY, P.C., HARDENBOL, J., JACQUIN, T. & VAIL, P.R. (eds.): Mesozoic and Cenozoc Sequence Stratigraphy of European Basins.− SEPM Spec. Publ., 60, 719–746. doi: 10.2110/pec.98.02.0719

GORIČAN, Š., KOŠIR, A., ROŽIČ, B., ŠMUC, A., GALE, L., KUKOČ, D., CELARC, B., ČRNE, A.E., KOLAR-JURKOVŠEK, T., PLACER, L. & SKABERNE, D. (2012): Mesozoic deep-water basins of the eastern Southern Alps (NW Slovenia).−
J. Alpine Geol., 55, 1–43.

GORIČAN, Š., ŽIBRET, L., KOŠIR, A., KUKOČ, D. & HORVAT, A. (2018): Stratigraphic correlation and structural position of Lower Cretaceous flysch-type deposits in the eastern Southern Alps (NW Slovenia).− Int. J. Earth Sci., 107, 2933–2953. doi: 10.1007/s00531-018-1636-4

GORIČAN, Š., HORVAT, A., KUKOČ, D. & VERBIČ, T. (2022): Stratigraphy and structure of the Julian Alps in NW Slovenia.– Folia Biolog. Geolog., 63, 61–83. doi: 10.3986/fbg0098

HAAS, J. & BUDAI, T. (1999): Triassic sequence stratigraphy of the Transdanubian Range (Hungary).− Geol. Carpathica, 50, 459–475.

HAAS, J., KOVÁCS, S., KRYSTYN, L. & LEIN, R. (1995): Significance of Late Permian-Triassic facies zones in terrane reconstructions in the Alpine-North Pannonian domain.− Tectonophysics, 242, 19–40. doi: 10.1016/0040-1951(94)00157-5v

JURKOVŠEK, B. (1986): Osnovna geološka karta SFRJ 1:100000, list Beljak in Ponteba L33−52, L33−51 [Basic Geological Map of SFRY 1:100000, Beljak and Ponteba sheet – in Slovenian].– Geološki zavod Ljubljana, Ljubljana, Zvezni geološki zavod, Beograd.

JURKOVŠEK, B. (1987): Osnovna geološka karta SFRJ 1:100000. Tolmač za list Beljak in Ponteba, L33−52, L33−51 [Basic Geological Map of SFRY 1:100000, Geology of the Beljak and Ponteba sheet – in Slovenian].– Geološki zavod Ljubljana, Ljubljana, Zvezni geološki zavod, Beograd, 58 p.

KOLAR-JURKOVŠEK, T. (1983): Srednjetriasni konodonti Slovenije.− Rudarskometalurški zbornik: revija za geologijo, rudarstvo in metalurgijo, 30, 323–364.

KOVÁCS, S., SUDAR, M., GRĂDINARU, E., GAWLICK, H.-J., KARAMATA, S., HAAS, J., PÉRO, C., GAETANI, M., MELLO, J., POLÁK, J., ALJINOVIĆ, D., OGORELEC, B., KOLAR-JURKOVŠEK, T., JURKOVŠEK, B. & BUSER, S. (2011): Triassic evolution of the tectonostratigraphic units of the Circum-Pannonian Region.− Jb. Geol. B.-A., 151, 199–280.

KOZUR, H.W., KRAINER, K. & MOSTLER, H. (1994): Middle Triassic conodonts from the Southern Karawanken Mountains (Southern Alps) and their stratigraphic importance.− Geol. Paläont. Mitt. Innsbruck, 19, 165–199.

KRAINER, K. & LUTZ, D. (1995): Middle Triassic basin evolution and stratigraphy in the Carnic Alps (Austria).− Facies, 33, 167–184. doi: 10.1007/BF02537450

LEEDER, M.R. & GAWTHORPE, R.L. (1987): Sedimentary models for extensional tilt-block/half-graben basins.– In: COWARD, M.P., DEWEY, J.F. & HANCOCK, P.L. (eds): Continental extensional tectonics.− Geol. Soc. Spec. Publ., 28, 139–152. doi: 10.1144/GSL.SP.1987.028.01.11

MIETTO, P., AVANZINI, M., BELVEDERE, M., BERNARDI, M., DALL VECCHIA, F.M., O’ORAZI PORCHETTI, S., GIANOLLA, P. & PETTI, F.M. (2020): Triassic tetrapod ichnofossils from Italy: the state of the art.− J. Mediterr. Earth Sci., 12, 83–134.

MOHRIG, D., WHIPPLE, K.X., HONDZO, M., ELLIS, C. & PARKER, G. (1998): Hydroplaning of subaqueous debris flows.− GSA Bull., 110, 187–394. doi: 10.1130/0016-7606(1998)110<0387:HOSDF>2.3.CO;2

NEMEC, W. & STEEL, R.J. (1984): Alluvial and coastal conglomerates: their significant features and some comments on gravelly mass-flow deposits.– In: KOSTER, E.H. & STEEL, R.J. (eds): Sedimentology of gravels and conglomerates. Can. Soc. Petrol. Geol. Mem., 10, 1–31.

PETEK, T. (1998): Scythian and Anisian beds in the quarry near Hrastenice and important finds of Upper Anisian fossils.− Geologija, 40, 119–151. doi: 10.5474/geologija.1997.006

PLACER, L. (2008): Principles of the tectonic subdivision of Slovenia.− Geologija, 51, 205–217. doi: 10.5474/geologija.2008.021

POLI, M.E. & ZANFERRARI, A. (1995): Dinaric thrust tectonics in the Southern Julian Prealps (Eastern Southern Alps, NE Italy).– In: VLAHOVIĆ, I. & VELIĆ, I. (eds): Proceedings of the first Croatian Geological Congress. Institute of Geology, Croatian Geological Society, Zagreb, 2, 465–468.

PROTHERO, D.R. & SCHWAB, F. (2013): Sedimentary geology: an introduction to sedimentary rocks and stratigraphy.– WH Freeman and Company, New York, 575 p.

RAMOVŠ, A. (2000): Über die Zlatnaplatte sensu Kossmat, 1913, Slatna-Decke sensu Buser, 1986, Slatna-Überschiebung sensu Jurkovšek, 1987 und Triglav-Decke sensu Ramovš, 1985.− Geologija, 43, 109–113. doi: 10.5474/geologija.2000.010

RETTORI, R. (1995): Foraminiferi del Trias inferiore e medio della Tetide: revisione tassonomica, stratigrafia ed interpretazione filogenetica.− Uni. Geneve, Publ. Départ. Géol. Paléont., 18, 1–107.

RIDING, R. (2000): Microbial carbonates: the geological record of calcified bacterial-algal mats and biofilms.− Sedimentology, 47, 179–214. doi: 10.1046/j.1365-3091.2000.00003.x

SALAJ, J., BIELY, A. & BYSTRICKÝ, J. (1967): Trias-foraminiferen in den Westkarpaten.− Geol. Práce, 42, 119–136.

SMIRČIĆ, D., ALJINOVIĆ, D., BARUDŽIJA, U. & KOLAR-JURKOVŠEK, T. (2020): Middle Triassic syntectonic sedimentation and volcanic influence in the central part of the External Dinarides, Croatia (Velebit Mts.).− Geol. Quarterly, 64, 220–239. doi: 10.7306/gq.1528

SOHN, Y.K. (2000): Coarse-grained debris-flow deposits in the Miocene fan deltas, SE Korea: a scaling analysis.− Sediment. Geol., 130, 45–64. doi: 10.1016/S0037-0738(99)00099-8

STEFANI, M., FURIN, S. & GIANOLLA, P. (2010): The changing climate framework and depositional dynamics of Triassic carbonate platforms from the Dolomites.− Palaeogeogr. Palaeoclimatol. Palaeoecol., 290, 43–57. doi: 10.1016/j.palaeo.2010.02.018

VELLEDITS, F., PÉRÓ, C., BLAU, J., SENOWBARI-DARYAN, B., KOVÁCS, S., PIROS, O., POCSAI, T., SZÜGYI-SIMON, H., DUMITRICĂ, P. & PÁLFY, J. (2011): The oldest Triassic platform margin reef from the Alpine-Carpathian region
(Aggtelek, NE Hungary): platform evolution, reefal biota and biostratigraphic framework.− Riv. It. Palaeont. Strat., 117, 221–268. doi: 10.13130/2039-4942/5973

VENTURINI, C. (1990): Geologia delle Alpi Carniche Centro Orientali.– Comune di Udine, Museo Friulano di Storia Naturale, Udine.

VENTURINI, C. (2006): Evoluzione geologica delle Alpi Carniche.− Ed. mus. Friulano stor. Nat., 48, 1–208.

WRIGHT, V.P. (1992): A revised classification of limestones.− Sed. Geology, 76, 177–185. doi: 10.1016/0037-0738(92)90082-3

ZANINETTI, L., RETTORI, R. & MARTINI, R. (1994): Aulotortus ? eotriasicus, n.sp., un nuovo foraminifero del Trias medio (Anisico) delle Dinaridi ed Ellenidi.− Boll. Soc. Palaeont. Ital., 33, 43–49.