Salt tectonics along a strike-slip fault system in the sub-Alpine chains of southeastern France, from the Triassic to the Oligocene

The Rouaine-Daluis fault system delimits an important structural boundary in the sub-Alpine chains of southeastern France. It is composed of multiple faults, which display net sinistral strike-slip offset, and link into a thick section of Triassic evaporites. We use cross sections, stratigraphic correlation, and schematic restorations to reinterpret the evolution of the Rouaine-Daluis fault system and highlight the importance of salt tectonics in its evolution. Observations in the northern region present new evidence for passive salt rise from Late Jurassic to Early Cretaceous (Aptian- Albian) along the fault system. At the end of this period, salt breached the surface, forming an extensive allochthonous salt sheet, which welded out diachronously as sediment was deposited on top. In the southern region, we identify a Roho-like geometry along an approximately north-south-trending normal fault known as the Braux fault, which developed during the Eocene-Oligocene. Restoration of the strike-slip deformation along the Rouaine-Daluis fault system shows approximately 5.5 km of the post -earliest Oligocene sinistral slip. When restored, the Braux fault in the southern region is brought adjacent to the salt structures in the northern region, in particular the Daluis dia-pir, highlighting their connected evolution. Alpine shortening, and associated strike-slip offset along the Rouaine-Daluis fault system, likely reactivated a salt wall along the system from the Late Cretaceous onward, as salt structures were squeezed and the salt was extruded to the surface.