Contribution to the Sedimentological, paleo environmental and paleogeographical study of Infra-Cenomanian sediments from the South Slope of the Central High Atlas (Morocco)

The sedimentological analysis of the lower Cretaceous red deposits in the Boumalne Dades region (Central High Atlas) presented in this article is based on field observations associated with sedimentological methods (morphoscopy, exoscopy, and mineralogy determination of clays) conducted to investigate the paleo-environment of this study area. The analysis of the surface of the quartz grains with a binocular magnifier and scanning electron microscopy (SEM), allowed us to reconstruct their formation environment. Exoscopic analysis allowed the characterization of a mixture of quartz morphotypes. The results obtained reveal numerous indications of short- and long-distance transport, which reflect different environments (continental to marine environment). The paleoenvironments of the units revealed by sedimentology are essentially continental with marine influences. Specifically, an alluvial fan is recorded at the base of the Ifezouane Formation at unit 1 and a fluvial meandering medium (unit 2) at the top of the same formation; the deposits of the Aoufous Formation correspond to a floodplain at the base (unit 3) and a playa at the top (unit 4).