The Carboniferous rocks of southern Morocco record the gradual change from the extensional tectonic style of the early Paleozoic to a compressional regime. During the Tournaisian and early Visean, northwest compression formed a rising anticline in the Anti-Atlas, which provided sediments to shallow marine basins formed in the flanking synclines. During the late Visean, tectonic activity increased markedly, and northward-downthrowing normal/oblique slip faulting formed submarine fault scarps. Turbidity currents and debris flows together with giant exotic blocks were shed northward from these scarps. The turbidity currents were deflected eastward to flow down the axes of these small easterly plunging marine basins. A late Visean phase of minor folding with locally developed cleavage and quartz veining closed these basins. The folded sequences are unconformably overlain by uppermost Visean fluvial sediments deposited from northward and eastward-flowing rivers.

During the Pennsylvanian, collisional tectonics recorded in the Moroccan Meseta to the north were probably responsible for thrust faulting and the formation of a high-angle cleavage. Thick (up to 4.5 km) sandstones and conglomerates with red mudstones, paleosols, and coals are preserved on the fringes of the area. These were deposited by southeast-flowing rivers and are interpreted as the eroded remnants of a syn-postorogenic molasse deposited in a major foredeep south of the main orogen.

AAPG Search and Discovery Article #91032©1988 Mediterranean Basins Conference and Exhibition, Nice, France, 25-28 September 1988.