Several marine geophysical profiles off the southern part of the Niger delta reveal the presence of diapiric structures beneath the continental slope and rise. The origin of the diapiric material appears to be deep in the sedimentary section and is believed to be of Aptian-Albian age. If this hypothesis is correct, the presence of evaporite basins, known between angola and Gabon, can be extended as far north as the Niger delta. [NOT CONTROLLED OCR]