Abstract
Several episodes are depicted in the evolution of the Maghreb Atlasic domain during the Mesozoic and Cenozoic: - during the late Triassic-early Liassic, the Atlasic rift developed in Morocco. The NE-SW trending halfgrabens resulted from the extensive inversion of Hercynian thrusts. The rifting episode early aborted during the early Liassic; - the Mid-Liassic postrift carbonate shelf was dislocated during the late Liassic. From Morocco to northern Tunisia, Atlasic troughs opened, en-echelon over the transform boundary of the Africa plate. The N070 degrees E trending troughs display a strong left-lateral component; the main deformation occurred during the late Jurassic in the axis of the Moroccan Atlas, the Eocene in the Algerian Atlas, and the Neogene in the central and southern Tunisian Atlas. The Neogene uplift of the whole Maghreb Atlas domain resulted from the Africa-Europe collision. In central and southern Tunisia, the left-lateral N070 degrees E faults are not represented, suggesting that the northern limit of the Africa plate ran north of present Tunisia during the Mesozoic. The geometry of the northern Africa boundary underlines the former southern limit of the Hercynian belt, reactivated at the beginning of the Mesozoic.
