-A new lithostratigraphic nomenclatural framework is proposed for the Anti-AtlasOrogen of Morocco, to replace the previous chronostratigraphic scheme. All Continued prolonged convergence gave rise to a sinistral transpressional regime in which late syn-to post-tectonic continental volcanic and clastic sequences of the Ouarzazate Supergroup were deposited. The first rocks of this new tectonic regime were deposited in narrow, tectonically active, strike-slip pull-apart rift basins (Bou Salda, Mgouna, Tafrawt and Anzi Groups), associated with intrusion of high-K calc-alkaline granitoid batholiths (e.g. Assarag, Bardouz Suites) and the juxtaposition of ophiolitic remnants in major strike-slip shear belts. These were followed by the deposition of the much more areally extensive continental volcano-sedimentary molasse, the volcanic components of which were erupted from several interfingering volcanic centres, often associated with caldera complexes and sub-volcanic alkaline granites 2 (Toufhgrane, Tanghourt and Guellaba Suites). The proposed lithostratigraphic scheme encompasses all the major rock units identified in the literature from the orogen and is flexible so that new, lower-ranking, units can be placed at the appropriate stratigraphic level in future. This framework is supported by new high-precision U-Pb zircon dates that have recently become available.