Facies and synsedimentary tectonics on a Badenian carbonate platform in the southern Vienna Basin (Austria, Central Paratethys)

Abstract

The Mannersdorf quarries at the northeastern edge of the Leitha Mountains (Lower Austria) preserve a record of pre-, syn- and post-tectonical phases of a Badenian carbonate platform in the Vienna Basin. The pre-tectonic phase is reported by a marine transgression with the development of a coastal slope scree and subsequent prograding of a Gilbert-type fan delta, overlain by very heterogeneous corallinacean limestones. A fault divides the study area into two independent tectonic blocks, which have been logged and subjected to detailed investigation and sampling. The corallinacean limestones of the first block indicate shallow-water environments (i.e., seagrass meadows) and gradual transitions from shallower to deeper environments, while the second block shows an unconformity, which is linked to a rapid facies change from relatively deeper environments (i.e., indicated by the abundance of in situ Pholadomya) to shallow waters (indicated by corals). Contrary to coral-bearing limestones of the same age at the southwestern part of the Leitha Mountains, corals are generally rare in the limestones of the Mannersdorf quarries, which represent mostly deeper environments with conspicuous differences in faunal associations. The onlap of limestones on a tectonic-caused flexure indicates syn-tectonical movements. Paleostress analyses verify a normal-fault reactivated as a dextral strike-slip fault. The temporal character of this fault is indicated by a post-tectonical phase with a marine transgression, a burial of the fault and neptunian dyke development.