PALINSPASTIC RECONSTRUCTION OF THE EASTERNMOST ALPS BETWEEN UPPER EOCENE AND MIOCENE

Year, pages: 1992, 327 - 331

During the Paleogene the SE flank of the Variscan Bohemian Massif stayed in a passive margin stage. In the Late Eocene clastic shelf sedimentation together with coralline-algal reefs were characteristic for this margin area. Coloured clays of deeper environments are comparable with the Helvetic sediments west of Vienna. Sedimentation in the Flysch trough south of it ceased at the end of the Eocene because of the northward progression of the Alpine nappe system. In the Early Oligocene the separation of the Paratethys began. A regressional phase together with a restricted environment took place. Laminated dark marls and shales were deposited during that period of tectonic inactivity. Beginning with Egerian the flank of the Bohemian Massif was increasingly loaded by the north to northwestward prograding Alps. The former shallow shelf area was turned into an Alpine foreland trough accompanied by a transgression onto the Bohemian Massif. Erosional canyon cuts and block horizons are characteristic for the tectonic unstable condition at the former shelf margin. The direction of nappe progradation and compression turned from N to NNW to the shelf edge. In the Eggenburgian cyclic Molasse sedimentation was predominant in the NNW prograding foreland trough. Clastic material was derived from the Alpine range. The maximum marine extension and transgression onto the Bohemian Massif occurred at that time. Thrusting changed to a NW direction. From the Ottnangian to Karpatian thrust movement slowed down. Because of the fixing of the Alpine nappes at the Spur of the Bohemian Massif near Vienna and the continuous progression of the Carpathian fold belt, extension occurred in a NE-SW direction. As a result the Vienna Basin was created on top of the stretched Alpine-Carpathian fold belt. After the nappe progression onto the Bohemian Massif ceased, a new NNE-SSW directed left lateral strike-slip movement dominated. The Vienna Basin turned into a pull apart basin during Badenian to Pannonian. From the Pontian until now, the NW-SE directed extension results in graben-like features along the SE flank of the Vienna Basin.

Seifert, P. 1992. PALINSPASTIC RECONSTRUCTION OF THE EASTERNMOST ALPS BETWEEN UPPER EOCENE AND MIOCENE. In Geologica Carpathica, vol. 43, no.6, pp. 327-331. 1335-0552.

Seifert, P. (1992). PALINSPASTIC RECONSTRUCTION OF THE EASTERNMOST ALPS BETWEEN UPPER EOCENE AND MIOCENE. Geologica Carpathica, 43(6), 327-331. 1335-0552.