Gravity anomalies, sub-surface structure and oil and gas migration in the Mamfe, Cameroon-Nigeria, sedimentary basin

Abstract

Preliminary gravity results for the Mamfe Basin in the border region of northwestern Cameroon with southeastern Nigeria are reported. No geophysical studies were available for this important area, which is genetically related to oil and gas deposits in the Benue Trough. Regional and residual gravity components were obtained by least-square fitting of a third-degree polynomial surface to the Bouguer anomaly. The residual anomalies feature two NE-SW gravity lows attributed to sedimentary infill about the localities of Ekok and Agbokem, about Mukonyong, Mamfe and Bachuo Akagbe. The gravity highs to the north and south are associated with outcrops of the basement complex. This structure corresponds to two major basins separated by a structural high. The deeper western sub-basin comprises two sub-basins separated by a minor structural high possibly related to the crystalline basement. These sub-basins tend to be shallower in the eastern direction possibly indicating the direction of migration of hydrocarbons. More detailed gravity and seismic studies may lead to discoveries of structural or stratigraphic traps. We conclude that the area is a promising prospect in terms of oil and gas prospecting.