Abstract The Moroccan salt basin remains one of the least explored of the west African salt basins. Although small producing fields in the onshore Essaouira Basin exist, so far, only subcommercial discoveries on the shelf have been made. During the last decade, three exploration wells were drilled in the deep water between Essaouira and Tarfaya in the central segment of the Atlantic margin of Morocco. These wells documented a general lack of reservoir-facies siliciclastics within the Cenozoic and Upper Cretaceous deep-water sequence. Compared to the other segments of the Atlantic margin, the Moroccan margin has had a fairly complex structural history since the Middle Jurassic breakup between the North American–African plates involving several well–documented Alpine compressional periods and mountain building in the adjacent Atlas Mountains. In particular, as the NeogeneHolocene inversion, uplift, and erosion of the Atlas system is very well documented onshore, the apparent lack of Upper Cretaceous and Cenozoic reservoirs in the first deep–water wells came as a surprise. Therefore, reservoir presence, as the most critical risk factor in the deep–water exploration of the Moroccan Atlantic margin, needs to be better understood before new exploration wells can be drilled. Based on regional evidence, the Lower Cretaceous and the Jurassic sequences are interpreted to be significantly more sand prone in the deep–water areas than the overlying Upper Cretaceous and Cenozoic strata.

Abstract The Moroccan salt basin appears to be very unique in the sense that it is not sedimentary loading but tectonic inversion which appears to drive the latest stages of salt-related deformation in the central part of the basin. The gravity potential to maintain salt tectonics is provided by the differential uplift of the Atlas Mountains, located adjacent and striking almost perpendicular to the margin. Along the offshore part of the Moroccan salt basin there are many play types, most of them related to the Triassic syn-rift salt. Toe-thrust anticlines at the basinwards edge of the salt basin form very large structures. Traps associated with salt tongues and diapirs define a more ‘classical’ salt-flank play. Numerous salt tongues, sheets and canopy complexes provide for a ‘Gulf of Mexico-style’ subsalt play. Despite the numerous untested play types, there have been only four deep-water exploration wells drilled in the entire Moroccan salt basin, none of them having subsalt penetrations.