Hercynian Basement Faults Control and Hydrocarbon Habitat in Morocco

A. Elouataoui, H. Jabour, and Ait Salem A.

Geologic, geophysical and remote sensing evidence shows that the Paleozoic basement of Morocco is fragmented at various scales. Wrench faults, difficult to identify by conventional methods were examined from a regional perspective and through careful observation and assessment of many factors. Subsurface structural mapping and geoseismic cross-sections supported by outcrop studies and geomorphological features revealed a network of strike slip faults.

Although controversy still surrounds interpretation of major faults as wrench type, with various amounts of strike-slip, or as reverse dip-slip with large amount of shortening, mapping of these basement fault block pattern in moroccan sedimentary basins revealed literally many correlations of these blocks with prospective structures. These range from simple fault traps, to horst blocks, to fracture systems, to assymetrical folds over reverse faults. Additionally, many types of stratigraphic traps correlate with basement shear zones. One example is the Middle Devonian algal mounds complex in the Doukkala Basin that evidently formed on fault scarps and/or fault-caused sea floor highs.

The present study demonstrates that most of defined prospective structures in Morocco result from basement fault control and considers precise mapping of these pattern a pervasive and prerequisite exploration approach to go forward in upcoming exploration programs.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California