Sedimentological and lithostratigraphic study of the Foum El Kous Senonian, Central Hight Atlas of Morocco

Abstract

The study area belongs to the southern edge of the central High Atlas. It is limited to the North by the Sub-atlasic accident and to the South by the extension of the Eastern Anti Atlas formations. To determine the depositional environments of the Senonian series, a sedimentological analysis of the facies was carried out based on field observations by the recognition of sedimentary structures and textures. An exoscopic analysis of the quartz grains was also carried out by a systematic prospecting of the grain relief and of all the characters that will appear on the surface of the grain after the formation of the mother rock at the origin place, during transport, immobilization phases and deposition. It seems very interesting to prospect for the clayey side in these Upper Cretaceous reddish formations because the evolution of the clayey and non-clayey assemblages in this central basin of the High Atlas will depend mainly on the combination of tectonic, eustatic, climatic and other influences. The Senonian of Foum El Kous which has a less important thickness corresponds to continental deposits that act the role of a natural barrier that separates on both sides the two sub-basins: Sidi Ali Oubork in the East and Ait youl in the West.