Evidence of Paleocene unconformable deposits with charophytes and ostracods on the anticline ridges of the Imilchil area (High Atlas, Morocco): Paleogeographic and structural implications

New sedimentological and biostratigraphical data have been obtained from unconformable series (Tasraft Formation) on some intruded anticlines located in the Central High Atlas of Morocco. Our results lead us to contest the previous Middle Jurassic to Middle Cretaceous ages only based on lithostratigraphic similarities. The Tasraft Formation proves to be a syntectonic series characterized by detritic fluvial sediments followed by lacustrine and lagoonal-marine limestones. Ostracods and charophytes found in different levels of the unconformable series indicate Thanetian ages. According to these new stratigraphical data, we can conclude that the main structures of the axial part of the High Atlas (folds, cleavage and exhumation of gabbroic bodies) were settled before the Late Paleocene. Moreover, the occurrence of Paleocene nonmarine beds in the axis of the High Atlas Belt implicates to modify the paleogeographic boundaries of the Atlantic transgressions in the beginning of the Tertiary. To cite this article: A. Charriere et al., C R. Palevol 8 (2009). (C) 2009 Published by Elsevier Masson SAS on behalf of l'Academie des sciences.