Upper Cretaceous deposits on the Northern side of the High Atlas Range of Marrakesh (Morocco): tectonics, sequence stratigraphy and paleogeographic evolution

Abstract

This paper presents a new interpretation of the paleogeographic evolution of the northern side of the High Atlas Range of Marrakesh (Morocco) based on a tectonic, lithological, sedimentological, and paleontological description of the three outcropping Upper Cretaceous Formations: The Anou-Nfeg Formation, the Aït Abbes Formation, and the Chichaoua Formation. In biostratigraphical terms, these formations areas signed to the Coniacian, Santonian, and Maastrichtian, respectively, and record three tectonic phases responsible for the geodynamic evolution of this part of the High Atlas Range. These phases are confirmed by the vertical elevation of the earth’s surface and the formation of some small restricted basins. A sedimentary pause corresponding to the Campanian has been recorded. Based on these findings, we conclude that these Formations were deposited in a confined environment influenced by the episodic marine incursions under a hot and humid climate.