Tectonics and sedimentation in the Fohnsdorf-Seckau Basin (Miocene, Austria): From a pull-apart basin to a half-graben
- Author(s)
- Philipp Strauss, Michael Wagreich, Kurt Decker, Reinhard Sachsenhofer
- Abstract
The Miocene intramontane Fohnsdorf-Seckau Basin is situated at the junction of the sinistral Mur-Mušrz-fault system and the dextral Pošls-Lavanttal fault system. The basin comprises a 2,400-m-thick coal-bearing fluviodeltaic-lacustrine succession (Lower to Middle Miocene, Upper Karpatian?/Lower Badenian) which is overlain by a 1,000-m-thick alluvio-deltaic conglomeratic succession (Apfelberg Formation, ?Middle/Upper Badenian) in the south. A three-stage model for the basin evolution has been reconstructed from structural analysis and basin fill geometries. During a first pull-apart phase, subsidence occurred along ENE-trending, sinistral strike-slip faults of the Mur-Mušrz fault system and NE-SW to N-S-trending normal faults, forming a composite pull-apart basin between overstepping en-echelon strike-slip faults. The Seckau and Fohnsdorf sub-basins are considered as two adjacent pull-aparts which merged into one basin. During the second phase, N-S to NNW-SSE extension and normal faulting along the southern basin margin fault formed a half-graben, filled by wedge-shaped alluvial strata (Apfelberg Formation). During the third phase, after the end of basin sedimentation, the dextral Pošls-Lavanttal fault system reshaped the western basin margin into a positive flower structure.
- Organisation(s)
- Department of Geology
- Journal
- International Journal of Earth Sciences
- Volume
- 90
- Pages
- 549-559
- No. of pages
- 11
- ISSN
- 1437-3254
- Publication date
- 2001
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 1051 Geology, Mineralogy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/f012a90c-a288-4295-a5c7-20cce483d30e