The Nigerian coastal basins (the Niger Delta and the Dahomey Basin) have been studied since the early 1950’s primarily for mineral and petroleum resources. These basins are two of several passive margins types (Klemme, 1980) located on the West African continental margin of Gulf of Guinea. In a tectonic plate context, the margin is considered translational (Grant, 1971; Burke, 1976), with its counterpart being the equatorial margin of Brazil (Ceara and Potiguar basins). As mentioned in Doust and Omatsola (1989 and this volume) and discussed by several authors (e.g., Burke, et al., 1971; Burke and Whiteman, 1973; Burke, 1976; Ajakaiye et al., 1986; Benkhelil et al., 1988; Babalola and Gipson, 1991), the origin of the West African marginal basins is related to tensional processes which broke the crust of the Gondwana supercontinent during the Jurassic. The breakup occurred along a series of rift zones of different orientations that met in a triple junction in the area of the present Gulf of Guinea at the location now occupied by the Niger Delta. Two of the arms, aligned along the SW and SE coasts of Nigeria and Cameroon, developed into collapsed continental margins of the South Atlantic, whereas the third, failed arm developed into the Benue Trough.
The separation of Africa from South America, which began some 130 Ma ago as a result of crustal stretching, faulting, and subsidence, occurred in a continent-to-continent transcurrent contact along the northern shore of Gulf of