Evaporites and red beds of a syn-rift Atlantic series: evidence of continental depositional environment (Berrechid sub-basin, Morocco)

Abstract

ABSTRACT The Berrechid sub-basin of Morocco consists of Late Triassic–Early Jurassic evaporites and red beds that are part of the syn-rift Atlantic series. Although some of the Berrechid sub-basin has been extensively studied, the depositional environment of the Upper Salt-Mudstone Formation has long been debated, with some early studies proposing a marine origin. This study documents the sedimentological, mineralogical, and geochemical characteristics of core materials from two boreholes and mine outcrops covering the entire series of the Upper Salt-Mudstone Formation. Our analysis of the lithology, mineralogy, sedimentary structures, sedimentary textures, and geochemical data suggests deposition in a continental setting. In addition, detailed observations of sedimentary structures and textures indicate additional features of periods of flooding, evapoconcentration, and desiccation. The continental setting in a dry climate is also supported by the occurrence of Classopollis pollen. This study provides new insights of the paleoenvironmental conditions in the Berrechid sub-basin, and significantly advances our understanding of the paleoenvironment and climate of Pangea during the Late Triassic–Early Jurassic period.