2D Seismic interpretation of strike-slip faulting, salt tectonics, and Cretaceous unconformities, Atlas Mountains, central Tunisia

The coeval dextral strike-slip motion along the three northwest-southeast bounding master faults (Gafsa, Sehib-Alima and Majoura-Mech) suggests a pull-apart opening of the Gafsa basin. Synchronous movements of the Gafsa first-order dextral strike-slip fault with the Sidi Ali Ben Aoun sinistral wrench fault caused formation of tectonic obstacles that are shown first by the sealed structures, then by development of the local compressive stress that caused formation of the south overturned folds and the syncline depressions. The transcurrent fault systems caused formation of Turonian and Senonian unconformities and hiatuses on the Sidi Aïch and Souinia-Majoura uplifts that corresponded to the Kasserine Islets. Sedimentary distribution and structural features indicate two events of regional deformation. The Albian-Cenomanian and Turonian transtensional displacements are demonstrated by depressions and grabens, with divergent reflectors striking against dipping growth fault. The Coniacian-Maastrichtian transpressional movements are marked by reverse faults and folds associated with pinch out structures and stratigraphic unconformities.