Structural evolution of the Maghreb Atlasic domains during Mesozoic and Cenozoic times. The role of inherited structures during the deformation of the North African margin

Several episodes are depicted in the evolution of the Maghreb Atlasic domai n during the Mesozoic and Cenozoic: during the late Triassic-early Liassic, the Atlasic rift developed in Moroc co. The NE-SW trending halfgrabens resulted from the extensive inversion of Hercynian thrusts. The rifting episode early aborted during the early Lias sic; the Mid-Liassic postrift carbonate shelf was dislocated during the late Lia ssic. From Morocco to northern Tunisia, Atlasic troughs opened, en-echelon over the transform boundary of the Africa plate. The N070 degrees E trendin g troughs display a strong left-lateral component; the main deformation occurred during the late Jurassic in the axis of the M oroccan Atlas, the Eocene in the Algerian Atlas, and the Neogene in the cen tral and southern Tunisian Atlas. The Neogene uplift of the whole Maghreb A tlas 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 ra n north of present Tunisia during the Mesozoic. The geometry of the norther n Africa boundary underlines the former southern limit of the Hercynian bel t, reactivated at the beginning of the Mesozoic.