ABSTRACT
The clay mineralogical analysis of th Late Jurassic/Cretaceous-Tertiary succession of the rift basins reveals three distinct zones; upper, middle and lower. These zone indicate environmental, tectonic and burial diagenetic controls on sedimentation. The clay assemblage which dominated by kaolinite suggest a warm and humid climate interrupted by. dry periods. Moreover, the clay geochemistry shows preferential enrichment and depletion of certain chemical elements in the rift basin environments, suggesting hydrolytic/environmental and diagenetic influences. Finally, both observed and predicted maturity indices indicate that the early active rifting phase strata are marginally to moderately mature. In contrast, the medial and final rifting phases strata are found to be largely immature. Two periods of oil generation have been recognized in the Campanian, Oligocene and Upper-Middle Miocene.
