Extensional detachment faulting in the evolution of a Tethys passive continental margin, Eastern Alps, Switzerland

The Austroalpine nappes of Switzerland represent an exhumed and tectonically imbricated segment of the passive continental margin of the Jurassic Tethys. Within one of these nappes (Err nappe), part of an upper-crustal, extensional detachment is preserved, indicating that the thinning of the crust was achieved by non-uniform extension. The Mesozoic age of the detachment is shown by comparison between its associated cataclasites and identical cataclasites that are found as redeposited components in Middle(?) Jurassic sedimentary breccias. This low-angle detachment within the basement was kinematically linked to synsedimentary high-angle normal faults at the surface. -from Authors