Middle Miocene drowned ramp in the vicinity of Marija Bistrica (Northern Croatia)

  • Jasenka Sremac University of Zagreb, Faculty of Science http://orcid.org/0000-0002-4736-7497
  • Kristina Tripalo University of Zagreb, Faculty of Science
  • Marko Repac University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering
  • Marija Bošnjak Croatian Natural History Museum
  • Davor Vrsaljko Croatian Natural History Museum
  • Tihomir Marjanac University of Zagreb, Faculty of Science
  • Alan Moro University of Zagreb, Faculty of Science
  • Borna Lužar-Oberiter University of Zagreb, Faculty of Science
  • Karmen Fio Firi University of Zagreb, Faculty of Science
  • Šimun Aščić University of Zagreb, Faculty of Science
Keywords: Langhian, transgression, palaeoenvironment, biostratigraphy, Medvednica Mt.

Abstract

Fossiliferous Middle Miocene deposits from the surroundings of Marija Bistrica (north-east of Zagreb) transgressively overly older pre-Cenozoic bedrocks. Fossils from shallow marine environments are in most cases preserved as bioclasts, while deep marine calcareous oozes characterize the pelagic marls. The age of the transgressive sequence is estimated on the basis of planktic biota from marls (foraminifera, nannoplankton and pteropods) as the Badenian NN5 Nannozone. The following palaeoenvironments can be distinguished or presumed on the basis of biota and sedimentary features: (1) beach characterized by polymictic conglomerates with rhodolith-rich carbonate matrix; (2) oyster banks, recognized from secondarily found oyster clusters; (3) lagoons marked with compact bioclastic deposits and rhodolith-halimeda assemblage; (4) patch-reefs recognized from the surrounding bioclastic deposits; (5) shallow subtidal mäerl beds preserved as loose bioclastic deposits and (6) distal slope argillaceous marls with pelagic biota. Palaeoenvironmental analyses indicate rapid drowning, most probably corresponding to the transgression during the Middle Badenian TB 2.4 3rd order transgressive-regressive sequence.

Author Biographies

Jasenka Sremac, University of Zagreb, Faculty of Science
Department of Geology, Full Professor
Kristina Tripalo, University of Zagreb, Faculty of Science
graduated student
Marko Repac, University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering
graduated student
Marija Bošnjak, Croatian Natural History Museum
Curator
Davor Vrsaljko, Croatian Natural History Museum
Curator
Tihomir Marjanac, University of Zagreb, Faculty of Science
Department of Geology, Associate Professor
Alan Moro, University of Zagreb, Faculty of Science
Department of Geology, Associate Professor
Borna Lužar-Oberiter, University of Zagreb, Faculty of Science
Department of Geology, Assistant Professor
Karmen Fio Firi, University of Zagreb, Faculty of Science
Department of Geology, Assistant Professor
Šimun Aščić, University of Zagreb, Faculty of Science
Department of Geology, Expert associate
Published
2018-04-30
How to Cite
Sremac, J., Tripalo, K., Repac, M., Bošnjak, M., Vrsaljko, D., Marjanac, T., Moro, A., Lužar-Oberiter, B., Fio Firi, K., & Aščić, Šimun. (2018). Middle Miocene drowned ramp in the vicinity of Marija Bistrica (Northern Croatia). Rudarsko-geološko-Naftni Zbornik, 33(4). Retrieved from https://hrcak.srce.hr/ojs/index.php/rgn/article/view/6544
Section
Geology