Early and middle Miocene paleobathymetry of the Vienna Basin (Austria)

Abstract

The Vienna Basin (VB) originated during the early Miocene and represents one of the largest onshore oil and gas field in Europe. The VB is composed of several horst and graben structures forming different subbasins, each with its own geodynamic evolution and deviating paleobathymetric developments during the Miocene. We present an analysis of water depth evolution along a NE-SW transect by applying a transfer function for benthic foraminifers. We document dramatic changes in the depth profile through time, which coincide with shifts of prevailing tectonic regimes. Bathyal conditions were established during the early Miocene piggy-back stage and the early middle Miocene extensional phase. A clear shallowing trend from upper bathyal to inner neritic conditions occurred during the middle Miocene extensional tectonic phase.All lowstand systems of relative sea level in the VB coincide with global Mi-events. The observed maxima of the relative sea level in the VB are vaguely in phase with the global record from the Ottnangian (late early Miocene) to the middle Badenian (middle Miocene) but exceed the range of global sea level rise by three to four times, suggesting a strong tectonic amplification. Fluctuations of the relative sea level during the late Badenian and Sarmatian (Serravallian, middle Miocene) range well within the global signal, documenting ceasing influence of tectonics.