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A review of the tectonic evolution, stratigraphic and structural framework, petroleum systems and hydrocarbon potential of the offshore portion of Rio Del Rey (RDR) Basin in Cameroon is presented in this paper. The RDR basin is a passive margin basin present in the Gulf of Guinea and it is located southeast of Niger Delta over an area of about 7,000 km 2 offshore. Its stratigraphic components, like those of Niger Delta, comprise of a diachronous succession of prodelta shales (Akata Formation), overlain by delta front sands and shales (Agbada Formation), in turn, overlain by fluvial sands (Benin Formation). The age of this basin ranges from Eocene to Recent and it consists of four structural provinces namely; the growth fault province in the north, the Cretaceous Onshore province in the southeast, the Shale Ridge province in the southwest, and the Delta Toe-thrust in the south-central region. The RDR Basin features three stages of tectonic development: Pre-rift phase (Late Proterozoic to Late Jurassic); Syn-rift phase (Late Jurassic to Early Cretaceous) and Post-rift phase (Late Cretaceous to Holocene). It presently stands out as the major contributor of the petroleum in the country.

This paper presents a review of the tectonic evolution, stratigraphy, paleontology, hydrogeological aspects and economic geology of the Mamfe basin. The main structures are basement -involved and detached fault and simple symmetrical fold with NE-SW trend. The basin measures 130 km in length and the widest part is about 60 km and a maximum area of 3200 km 2 . The maximum sediment thickness is estimated at 4-7 km and the sedimentary infill includes a lower alluvial fans to fluvial basal conglomerate and conglomeratic sandstone, a middle alternating (cyclic) aqueous to anoxic deep lake bottom black shale and limestone unit and an upper fluvial to transitional deltaic nearshore conglomeratic sandstone unit. The Ostracod fauna from the shale are very similar to the coeval fauna from adjacent Benue trough. The reported fauna have no biostratigraphic significance because of their uncertain age, low diversity, and cosmopolitan distribution during the early Cretaceous. Over 30 salt springs exist across the Mamfe basin with the most concentrated yielding 79 g/L of high quality halite. Several mineral indices (including diamond) have been identify and the geological condition favour the occurrences of hydrocarbon.