Stratigraphic and tectonic architecture of the Middle Jurassic-Upper Cretaceous at the southern front of the Central High Atlas (Morocco): a cartographic revision

Abstract

The Middle Jurassic (Bathonian)-Upper Cretaceous (Maastrichtian) deposits exposed at the southern front of the Central High Atlas (CHA, Southern Morocco) include thick fluvial successions largely undifferentiated in previous studies. These continental strata record a long period of relief formation due to crustal shortening and subsequent denudation that predated the Cenozoic, syn-collisional, tectonic inversion of the CHA. This study, carried out through mapping along more than 270 km between Ouarzazate and Errachidia towns, firstly proposes a rock-stratigraphic unified scheme based on a framework of unconformity-bounded stratigraphic units, including sub-units, differentiated for their specific depositional meaning. Secondly, the geological maps and related cross-sections illustrate the evidence of syn-depositional shortening with distinct deformation styles, outlining pre- and syn-collisional tectonic inversion.