Tectonics and sedimentation in the Fohnsdorf-Seckau Basin (Miocene, Austria): from a pull-apart basin to a half-graben

  • Philipp Strauss
  • , Michael Wagreich
  • , Kurt Decker
  • , Reinhard F. Sachsenhofer

Research output: Contribution to journalArticleResearchpeer-review

31 Citations (Scopus)

Abstract

The Miocene intramontane Fohnsdorf-Seckau Basin is situated at the junction of the sinistral Mur-Mürz-fault system and the dextral Pöls-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-Mürz 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 Pöls-Lavanttal fault system reshaped the western basin margin into a positive flower structure.
Original languageEnglish
Pages (from-to)549-559
Number of pages11
JournalInternational Journal of Earth Sciences
Volume90.2001
Issue number3
DOIs
Publication statusPublished - 1 Aug 2001

Keywords

  • Eastern Alps
  • Half-graben
  • Intramontane basin
  • Miocene
  • Pull-apart basin
  • Syntectonic sedimentation

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