Abstract: Basin evolution in the Vienna basin compared to surrounding basins; inferences from quantitative basin modeling and subsidence analyses

LANKREIJER, ANCO, KURT DECKER, and SIERD CLOETINGH

The evolution of the Vienna basin has been studied by means of subsidence analyses of over 70 wells, and additionally forward modeling along selected seismic sections has shown the particular features of the pull-apart Vienna basin. The Vienna basin formed as a reaction to large-scale eastward movements along of the Pannonian basin system with respect to the European foreland. Whether these movements are due to escape tectonics away from the Alps, or related to the extensional processes forming the Pannonian basin system or to a combination of both is at present not resolved. The pull apart set ting is manifested by the large-scale strike slip faults bordering the basin, the South-East and North-West. Large-scale normal faults along the basin margins in especially the east, like the Steinberg fault with an offset of several km's, are of a synsedimentary nature and show ongoing movement until Pannonian times (10Ma). Southward depocenter migration is also supposed to be related to the pull-apart nature of the Vienna basin. Although rheological models for the lithosphere underlying the Vienna basin predict a relatively stiff behavior in response to loading, paleogeographic reconstructions of the basin fill, indicate a more localized compensation of the load of the basin. Surrounding basins, like the Danube basin (Kisalfold or Little Hungarian Plain basin) and the Styrian basin do not show a pull-apart type basin evolution, however the tectono-sedimentary record of these basin shows striking similarities with the Vienna basin. Opening of the basin occurred at 17Ma, during Karpatian times, indicated in the subsidence history by a well defined phase of rapid subsidence. Later subsidence rates in general slowly decrease in magnitude. Arguments for intracrustal detachment, leading to thin-skinned extension will be compared with indications for whole lithospheric extension.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria