Resumen de The role of tectonics and climate in the development of Tertiary continental sequences; southeastern edge of the Atlas Mountains (Morocco)
The South-eastern Atlas Mountains (Morocco) pass to the adjacent foreland (Boudenib Basin) through the "Accident sud-atlasique" (ASA) located at the southern edge of the Atlas Chain. The Boudenib basin shows complex continental Tertiary sequences that allow to know how the tectonics and climate interacted during the sedimentation. During Senonian time, the Boudenib Basin subsided rapidly and filled with detritus derived from the adjacent highlands uplift, resulting in conglomerates which are organized into two main upward-thickening (300m) and coarsening deposits. They are observed basinward at the base of the Hamada de Boudenib I (Lower Eocene), which represents a palustrine environment and records a period of tectonic stability and an alternating dry and wet climate. The tectonic reactivation during Middle to Late Eocene in the Boudenib Basin led to a differential distribution of Hamada Boudenib II deposits which are mainly represented by carbonate lacustrine to palustrine environments indicating dry climatic conditions. During Lower Miocene to Pliocene, tectonic rejuvenation occurred along the ASA in response to the major Atlasique Phase (Atlasique phase II, Middle Miocene). At the beginning, the Boudenib Basin was dominated by proximal fan facies in the border that prograded southward and marked an unroofing surface at the base of the Hamada du Guir sequence. The upper part of the Hamada de Guir sequence is mainly dominated by calcrete and silcrete facies that indicate seasonally climate control (ared to semi-arid).
