The detritic series of the Upper Cretaceous region of Boumalne Dades (upper Central Atlas (Morocco): Sedimentary and paleo-environmental evolution

The stratigraphic, sedimentological study was carried out on the red formations of the South side of high central atlas (Boumalne). From a sedimentary point of view, sediments are dominated by the sandstone, clay and silty fraction accompanied by the conglomerate fraction. The analyses carried out show the abundance of purely continental sediments at the base of the studied formation and marine sediments at the summit (greenish clay with presence of organic matter). The morphoscopic study of quartz grains shows the abundance of grains of blunt or sub-blunt forms. The Exoscopy shows that these grains had a complex sedimentary history (alteration, continental aquatic transport) prior to their immobilization episode in the study area. Clay mineralogy suggests that the origin of smectite, kaolinite and illite sediments should be investigated in the watershed of the study area. The sedimentological study showed that detritic materials of continental origin and sediments resulting from coastal erosion are subjected to a dynamic that is controlled essentially by the action of currents mainly in water. From an environmental point of view, infra-Cenomanian is fluviatile, it is a filling of channels in a flood plain. These channels have characteristics on their stay in a vadose zone, several clues argue in this direction.

کلیدواژه ها:

Sedimentology ، Quartz ، Morphoscopic ، Exoscopic ، paleoenvironmental ، High central atlas.