Jurassic stratigraphy and synsedimentary tectonics on median part of central High Atlas, Morocco

Stratigraphical studies carried out in the Aït Bou Guemmez area (Central High Atlas, Morocco), lead us to precise the nature and the spatial organisation of liasic deposits. The series is composed of four sedimentary units:... [ view full abstract ]

Stratigraphical studies carried out in the Aït Bou Guemmez area (Central High Atlas, Morocco), lead us to precise the nature and the spatial organisation of liasic deposits. The series is composed of four sedimentary units: Hettangian? - Lower Sinemurian; Upper Sinemurian - Lower Carixian; Middle Carixian - Upper Domerian; Late Domerian - Toarcian pp., each of these produces a cyclic evolution: transgressive then regressive. These units are limited by regional unconformities, coinciding with the main periods of accentuating the structuration in the axis of the central High Atlas belt.
The structural analysis undertaken in various sites along Jbel Tizal - Jbel Azourki fault, shows a local framework us distention during all the Lias, related to the phenomenous of rifting which has marked out the ouest-tethysian margin durand the Lias. The direction of extension NW - SE recorded in the lower Lias implies the continuity, in the central High Atlas, of the same mecanisms responsible for the creation of the basin of Upper Trias at the Atlasic domain. The one which is oriented NE - SW during the Middle - Upper liasic periods implies a reorientation of the main contraints axis in the region of Aït Bou Guemmez. This change induce a new geodynamic evolution of which left overs to specify the mecanisms at the scale of Atlasic domain.