Post-EX4 Sat 15. September 2018 1 day
Sedimentation and tectonics in the type-Gosau basin (Upper Cretaceous – Paleogene), Northern Calcareous Alps
Guide: Michael Wagreich
This one-day field trip examines the type locality of the Gosau Group in respect of its sedimentary fill, stratigraphy and tectonic setting, deposited during and after major tectonism in the Austroalpine unit of the Northern Calcareous Alps. Selected outcrops of Upper Cretaceous to Paleogene rocks of the Gosau type-locality will be visited, and controls on sedimentation, sediment provenance and faulting will be discussed as well as the significance for Alpine orogeny. Sediments include terrestrial conglomerates, shallow-water fossiliferous marls up to deep-water mass-flow deposits. Sediment provenance changes from local to ophiolite-influenced to exhuming Austroalpine basement units. Basin margin faults for an early pull-apart basin formation phase, and later regional subsidence due to large-scale tectonism will be discussed.
Red pelagic marly limestones of the Nierental Formation in the Postalm section. Picture: M.Wagenreich
View from the Lake Gosau to the Triassic Dachstein Mountain and the Gosaukamm, margin of the Cretaceous Gosau basin. Picture: M.Wagenreich