The Tamsweg Tertiary in the Lungau region (Austria): Facies and deformation of an intramontane basin

The Tamsweg basin has been filled during Karpathian times by conglomerates, gradually upward fining clastics, and finally silty lacustrine sediments. Pebbles of Upper-Austroalpine provenance were supplied from the N and NE, l ater from the W. Basin formation started within negative flower structures along the sinistral Seetal fault. Synsedimentary tectonic activity is indic ated by local layers of cobbles at fault scarps, turbiditic lake sediments with slumps and coarse elastic mass flows, and ductile deformation of peat which has later been transformed into coal. Due to tectonic denudation of t he Tauern window a rollover basin developed and sedimentation extended to t he S onlapping onto a hilly paleorurface (Nock area). Dextral compressive r eactivation of the Seetal fault at the beginning of the late Miocene induce d basin inversion, in line with the end of lateral extrusion of the Eastern Alps. NNE-SSW directed compression and sinistral displacement is separatin g the basin since then into differentially uplifting blocks.