JOBIDON, GUY P., Soquip, PCIAC-ONAREP Project, Agdal Rabat, Morocco

Potential Cretaceous Play in the Rharb Basin of Northern Morocco

The autochthonous Cretaceous in the Rharb basin of Northern Morocco is located underneath a cover of Neogene sediments and of the Pre-Rif nappe olistostrome which was put in place during the Tortonian 7 m.y. ago. The presence of the infra-nappe Cretaceous sediments is documented by a few onshore wells of the Rharb basin and in the adjacent Pre-Rif Rides area as well as in the Rif mountains. Their presence in the deeper portion of the Rharb basin is difficult to detail because of the poor penetration of seismic data through the dispersive Pre-Rif nappe.

A recent study of offshore seismic data acquired by PCIAC in 1987 indicates that the infra-nappe interval can be more than 1500 meters thick in some of the offshore Kenitra area. These sediments have seismic signatures that would correspond to Middle Cretaceous transgressions culmunating with a Turonian highstand. Their deposition systems were located on the northern and western flanks of the Meseta and were followed by a hiatus lasting until the Miocene period.

Regional studies of gravity and magnetic data provide an additional understanding of the Rif province, its evolution and the possible presence of autochthonous Cretaceous sediments below the Pre-Rif nappe cover.

The Rharb's infra-nappe has a good potential to develop in a major hydrocarbon play with the presence of middle Cretaceous reservoir-rocks, Turonian-Cenomanian black shales source rocks, as well as the timely combination of trap formation, source rock maturation and hydrocarbon migration.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.