Intracontinental Rifting and Inversion: The Atlas Mountains and Missour Basin of Morocco

Weldon Beauchamp, Muawia Barazangi, Francisco Gomez, Ahmed Demnati, Mohamed El Alji

The intracontinental High and Middle Atlas mountain belts in Morocco intersect to form the southern and western margins of the Missour basin. This intermountain basin offers an opportunity to study the structural geometries and sedimentation in the intraplate Mesozoic rift systems of North Africa, and the subsequent Cenozoic structural inversion styles. The Missour basin provides valuable information concerning the timing of the uplift of the adjacent Atlas mountain system. By utilizing subsurface and surface methods the geodynamic progression of processes in Morocco and the North African plate from the Paleozoic to the Recent can be better understood. Observations based on seismic reflection profiles and wells collected over the Missour basin for hydrocarbon exploration emonstrate extensional syn-rift phases of deformation, and subsequent post-rift compressional phases of deformation. Results indicate the reactivation of rift related high angle normal faults, and the contemporaneous formation of low angle thrust faults. Field work was undertaken to determine more accurately the geometries and kinematics of faults observed or inferred on seismic reflection data. Preliminary results of field work indicates several phases of deformation (normal, reverse, oblique, strike-slip) along faults exposed in the basin and the adjacent Atlas mountains. The study of the effects of inversion in the Missour basin may lead to the recognition of footwall type hydrocarbon traps in the Mesozoic, following the remigration of hydrocarbons generated during rifting.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995