Kinematics of Structures and Basin Evolution in the Central High Atlas. Constraints from AMS and Paleomagnetic Data

Abstract

AbstractFrom the application of the magnetic techniques (Anisotropy of Magnetic Susceptibility and paleomagnetism) it can be seen that to determine the age (and origin) of structures in the Moroccan Central High Atlas is not straightforward from geometrical features only and that similar structures can have different origins, or that the two limbs of a particular structure can have developed at different times. A classification of structures is proposed showing all these possibilities. As a general rule, many structures were initiated before compression and, with local exceptions associated with salt structures, paleo-dips were shallow at the remagnetization stage. This has allowed the restoration of structures and the characterization of the overall geometry of the atlasic basin as a narrow, steer’s head strongly subsiding basin whose geometry strongly conditioned its tectonic inversion during the Cenozoic compressional stage. As a synthesis, the Central High Atlas constitutes a good example of intra-plate chain in which different models of basin formation (continental rifting, salt tectonics, transtension) and inversion (thrust tectonics, transpression, buttressing and internal deformation…) can be tested and visualized.