Early Oligocene N-NW thrusting in the external western Alps before the onset of

thrusts, which are classically assigned to the Pyrenean-Provence tectonic history because of their « transverse » orientation. The development of the Paleogene flexural basin marked the propagation of the Alpine orogenic wedge in the Western Alps. These sy-norogenic sediments make possible to distinguish some older compressive structures, which are sealed by them, from younger deformations which af-fect those sediments. Only the former structures (D1), which pre-date Alpine flexural subsidence, may be due to the Pyrenean-Provence orogenesis. Th