Post-nappe brittle extension in the inner Western Alps (Schistes Lustre's) following late ductile exhumation: a record of synextension block rotation?

Fault data collected from the Schistes Lustre's domain point to the existence of successive steps of deformation and indicate that extension is not multidirectional. This study underlines the continuity between the patterns of late brittle/ductile exhumation tectonics and brittle deformation, and strenghtens the view that extensional movements dominate in shallow levels of the inner Western Alps since at least 35-30 Ma. The progressive clockwise rotation of the earliest directions of extension with time is compatible with the amount of anticlockwise rotation from c. 35 Ma determined by recent palaeomagnetic studies, whereas the last documented N-S extension may reflect a short-lived stage of orogen-parallel extension.