Cenomanian-Turonian organic sedimentation in North-West Africa: A comparison between the Tarfaya (Morocco) and Senegal Basins

To explain the organic contrast between both environments a depositional model has been developed which is based on limited water exchange between both depositional settings. The main factor which has determined black shale sedimentation is the restricted water circulation related to the presence of isolated depositional environment during Atlantic Ocean opening. Compared to present upwelling zones, the palaeoproductivity in the studied area was relatively moderate during Cenomanian-Turonian and seems not to be the only determining factor of organic matter accumulation.