alpshop2022-61
https://doi.org/10.5194/egusphere-alpshop2022-61
15th Emile Argand Conference on Alpine Geological Studies
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Migration of basin formation and contrasting deformation style in the south-western Pannonian Basin (central Europe)

László Fodor1,2, Attila Balázs3, Gábor Csillag2,4, István Dunkl5, Gábor Héja6, Péter Kelemen5,7, Szilvia Kövér1,2, András Németh8, Anita Nyerges1, Dániel Nyíri8,1, Éva Oravecz1,2,3, Ildikó Selmeczi6, Balázs Soós8, Lilla Tőkés1, Marko Vrabec9, and CSilla Zadravecz8
László Fodor et al.
  • 1Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Geology, Budapest, Hungary (lasz.fodor@yahoo.com)
  • 2MTA-ELTE Geological, Geophysical and Space Research Group at Eötvös University
  • 3ETH Zürich, Department of Earth Sciences, Zürich, Switzerland (attila.balazs@erdw.ethz.ch)
  • 4Institute for Geological and Geochemical Research, Research Centre for Astronomy and Earth Sciences, Budapest, Hungary
  • 5Geoscience Center, University of Göttingen, Germany, (istvan.dunkl@geo.uni-goettingen.de, kelemenpeter1991@gmail.com)
  • 6Supervisory Authority of Regulatory Affairs, Budapest, Hungary (gabor.heja@sztfh.hu, ildiko.selmeczi@sztfh.hu)
  • 7Department of Petrology and Geochemistry, Institute of Geography and Earth Sciences, Eötvös University, Budapest, Hungary
  • 8MOL Ltd. 1117 Budapest, Hungary (anemeth@mol.hu, dnyiri@mol.hu, basoos@mol.hu, cszadravecz@mol.hu)
  • 9Department of Geology, University of Ljubljana, Slovenia (marko.vrabec@geo.ntf.uni-lj.si)

The Pannonian Basin is a continental extensional basin system with various depocentres within the Alpine–Carpathian–Dinaridic orogenic belt. Along the western basin margin, exhumation along the Rechnitz, Pohorje, Kozjak, and Baján detachments resulted in the cooling of variable units of the Alpine nappe stack. This process is constrained by thermochronological data between ~25–23 to ~15 Ma (Fodor et al., 2021). Rapid subsidence in supradetachment sub-basins indicates the onset of sedimentation in the late Early Miocene from ~19 or 17.2 Ma. In addition to extensional structures, strike-slip faults mostly accommodated differential extension; branches of the Mid-Hungarian Shear Zone (MHZ) could also play the role of transfer faults.

During this period, the hanging wall margin of the detachment system, i.e., the pre-Miocene rocks of the Transdanubian Range (TR) experienced surface exposure, karstification, and terrestrial sedimentation. After ~14.5 Ma faulting, subsidence, and basin formation shifted north-eastward and reached the TR where fault-controlled basin subsidence lasted until ~8 Ma.

3D thermo-mechanical forward models analyze this depocenter migration and predict the subsidence and heat flow evolution that fits observational data. These models consider fast lithospheric thinning, mantle melting, lower crustal viscous flow, and upper crustal brittle deformation. Models suggest ~150–200 km of shift in depocenters during ~12 Myr.

Simultaneously with depocenter migration, the southern part of the former rift system, near or within the MHZ, underwent ~N–S shortening; the early syn-rift basin fill was folded and their boundary faults were inverted. Deformation was dated to ~15–14 Ma („middle” Badenian) and continued locally to ~9.7 Ma while north of the MHZ the TR was still affected by modest extensional faulting. The particularity of this shortening is that it happened during the post-rift thermal cooling stage. The low-rate contraction and related uplift rarely exceeded this regional thermal subsidence.

MOL Ltd. largely supported the research. The research is supported by the scientific grant NKFI OTKA 134873 and the Slovenian Research Agency (No. P1-0195).

Fodor, L., Balázs, A., Csillag, G., Dunkl, I., Héja, G., Jelen, B., Kelemen, P., Kövér, Sz., Németh, A., Nyíri, D., Selmeczi, I., Trajanova, M., Vrabec, M., Vrabec, M. (2021): Crustal exhumation and depocenter migration from the Alpine orogenic margin towards the Pannonian extensional back-arc basin controlled by inheritence. Global and Planetary Change 201, 103475. 31p. https://doi.org/10.1016/j.gloplacha.2021.103475

How to cite: Fodor, L., Balázs, A., Csillag, G., Dunkl, I., Héja, G., Kelemen, P., Kövér, S., Németh, A., Nyerges, A., Nyíri, D., Oravecz, É., Selmeczi, I., Soós, B., Tőkés, L., Vrabec, M., and Zadravecz, C.: Migration of basin formation and contrasting deformation style in the south-western Pannonian Basin (central Europe), 15th Emile Argand Conference on Alpine Geological Studies, Ljubljana, Slovenia, 12–14 Sep 2022, alpshop2022-61, https://doi.org/10.5194/egusphere-alpshop2022-61, 2022.