(a) Panorama of the Le Caire valley showing the Oligocene and the Terres Noires formation strata abutting against the Le Caire salt wall at the boundary between the Authon–Valavoire thrust sheet and the autochtonous. (b) Present day interpretative cross-section through the Le Caire salt wall. (c) Interpretative cross-section during Oligocene of the Le Caire salt wall, showing the Liassic carapace on top of the salt wall.