Abstract

An attempt is made to establish the stratigraphy of the Devonian applicable to the region by means of correlations established in the central hercynian massif, western Morocco and the high Atlas, and by a sequence of twenty stratigraphic units based on the correlations to the south of the Anti-Atlas. This attempt has resulted in retaining temporarily, as usable only in the general correlations, nine subdivisions which from the faunas listed have been able to be referred to the classic stratigraphic scale: a Gedinnian-Lower Siegenian (“Lochkovian”), an upper Siegenian-Lower Emsian (“Praguian”), a true upper Emsian, an uppermost Emsian-Lower Eifelian, an upper Eifelian-Lower Givetian, an Upper Givetian-Lower Frasnian, an Upper Frasnian, a Lower Famennian and an Upper Famennian including the Etroeungt Zone. The formations assigned to these subdivisions are present in a variety of facies, but there is a predominance of clastic formations west of Morocco and south of the Tindouf basin, a maximum of carbonate in the Lower Emsian to Upper Frasnian; the dominant direction of the isopach lines is south-southwest in the west or easterly in the east. The maximum thicknesses are present in the west and southwest of Morocco, the minimum thicknesses in the southeast (central High Atlas and Tafilalt.).

Important movements took place at the end of the Lower Frasnian; their maximum effects (faults or folds) are seen around the eastern Anti-Atlas along north-south or northwest-southeast lines.

The essentials of the stratigraphic data and correlations are illustrated in the figures as well as an interpretation of the conditions of deposition along the southern front of the Anti-Atlas.