Lithostratigraphic and Paleoenvironmental Characterization of the Senonian Series of the Errachidia-Boudenib-Erfoud Basin, South-East Morocco

Abstract

Six lithostratigraphic sections distributed in different parts of the Errachidia-Boudenib-Erfoud basin (SE Morocco) were surveyed bed by bed and sampled in order to study stratigraphy, analyzed the facies, and characterized the depositional environment of the Senonian series. This study shows that this series is mainly constituted of three lithostratigraphic units: the first one is mixed, attesting to an alluvial plain environment disturbed by marine incursions at the base. The second is dominated by "kerkoub" sandstone bars intercalated by silt-clay intervals, reflecting a floodplain environment. The third is dominated by gypsum versicolored facies, marking an evaporitic playa environment. The correlation of the studied sections shows that the Senonian sedimentary prism opens progressively to the East. The series ends with Tertiary deposition: western marine carbonates and eastern continental conglomerates. The non-deposition of these faces in the center of the basin could be the result of the presence of a paleorelief at the Tinejdad-Goulmima transition.