Western Nigerian continental shelf, morphology, sediment pattern and Holocene transgressional phases of the coastline

The Western Nigerian continental shelflies approximately between longitudes 2°42'-5°00'E. It is a relatively gently sloping shelf incised by two Canyons, Avon and Mahin. The shelf is narrow and varies in width from about 24 km in the west to about 30 km in the east. The beaches between longitudes 2°42'E and 4°30'E are sandy while between longitudes 4°30'-5°00'E, they have a muddy consistency. This is referred to as the ~'Mahin Mud Beach". The sand deposits between 2°42'-4°30'E extend about 12 kilometers offshore and is separated into two coast parallel sand bodies by a narrow dark grey silty mud facies, 1-2 km wide. East of longitude 4°30'E, the sand facies is replaced by the Mahin Mud Beach. Results of analysis of echograms show that the PleistocenelEarly Holocene transgression of the coastline occurred in a rising sea level curve punctuated by about four sea-level stillstands.