20.500.12556/RUL-138223 Upper Campanian bentonite layers in the Scaglia-type limestone of the northern Dinarides (SE Slovenia) The research area is located in south-eastern Slovenia and belongs to the eastern extensions of the Slovenian Basin adjacent to the Adriatic Carbonate Platform. The studied section is 25 m thick and consists of grey, brownish and reddish pelagic limestones and calciturbidites, and two bentonite layers 110 and 10 cm thick. Both volcanoclastic horizons consist of greenish, fine-grained muddy material. To date, no other bentonites of similar age are known in the wider Southern Alpine and Dinaridic region. The late Campanian to Campanian/Maastrichtian age of the succession was determined from planktonic foraminifera and calcareous nanoplankton assemblages. XRD analysis revealed the presence of calcite, quartz, muscovite/illite and smectite, which prevails in the clay fraction and is indicative of bentonite clays. We interpret these bentonite horizons as resulting from direct deposition of volcanic ash in a marine environment with a concomitant admixture of detrital material (quartz, muscovite) and later diagenetic carbonatization. The geochemical composition suggests a felsic volcanic origin. The most likely source is the Late Cretaceouse–Paleogene bimodal rhyolitic/basaltic volcanism documented along the Sava Suture Zone in present-day Croatia, Bosnia and Herzegovina, Serbia, and North Macedonia. In the Central Apennines three locations with bentonites have been documented. Further spatial and temporal analysis of similar volcanogenic horizons could yield important data on the paleogeographic and tectonic evolution of the Adria/Apulia continental margin. Campanian bentonite biostratigraphy arc volcanism Adria margin Slovenian Basin true false true Angleški jezik Ni določen Članek v reviji 2022-07-13 03:47:46 2022-07-13 12:12:56 2022-09-15 04:16:25 0000-00-00 00:00:00 2022 0 0 20 str. art. 105158 Vol. 134 2022 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 55 0195-6671 10.1016/j.cretres.2022.105158 97302531 1-s2.0-S0195667122000222-main.pdf 1-s2.0-S0195667122000222-main.pdf 1 4E2F4743A0B023D3D59DA9AF85FA8B4D 8743b36c680c0e41ee04d66eb6d27ed7ed54989eae70f488eb196e8127d8d47f 797c3f63-2ab9-11ed-92af-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=160046 https://www.sciencedirect.com/science/article/pii/S0195667122000222 0 4304d685-2ab9-11ed-92af-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=160045 Naravoslovnotehniška fakulteta 0 0 0