Triassic-Jurassic extensional systems and their Neogene reactivation in northern Morocco (the Rides Prerifaines and Guercif Basin)
Bally, Albert W.
Doctor of Philosophy
The "Rides Prerifaines" of northern Morocco represent an unusual type of inversion that inverts only the sedimentary fill of a complex Triassic-lower Jurassic half-graben system, without significantly involving the underlying basement. Frontal and lateral ramp anticlines form over underlying Triassic-lower Jurassic east-west and southwest-northeast trending extensional faults. The Upper Miocene-Pliocene deformation of the Rides Prerifaines follows the emplacement of the large accretionary wedge of the Nappe Prerifaine deformation which occurred earlier i.e., during the Tortonian-Messinian interval. Significant structures that underlie the Neogene Guercif basin are Upper Cretaceous-Eocene basement-involved partial inversions of Jurassic half-grabens. The overlying Neogene Guercif basin begins with some Tortonian transtensional normal faulting that is followed by late Neogene compression. The overall northward thickening of the Neogene Guercif, Saiss and Rharb foredeep is typical for the flexural loading by the Prerifaine accretionary wedge and the overlying Neogene basin fill.