DISTRIBUTION OF THE 27 DOMINANT SPECIES OF SHELF BENTHIC FORAMINIFERSON THE CONTINENTAL-SHELF, NORTH OF DAKAR (SENEGAL)

One hundred and thirty-one samples were collected on the shelf and on the uppermost slope (down to 180 m) off Northern Senegal, between 14 d egrees 50' amd 16 degrees 20'N latitude. Two hundred and three species of benthic foraminifers were recognized. Most of them were reported i n previous works, along the coast of Africa. Twenty seven species are selected for detailed analysis and distribution maps are given for eac h of them. Q mode and R mode statistical analyses were performed on th ese selected species. The distribution is mainly related to depth; the second factor of distribution is the nature of the sediments: about 3 0% of the study area is covered by the muddy sediments of the pro-delt a of the Senegal river. Hierarchical analysis shows that the main limi t in the pattern of change of these 27 species with depth is about 60- 65 m. A depth index Di: calculated on the basis of twelve selected spe cies, gives a depth indication with a precision of about 40 m over the shelf. It is possible to envisage a possible use of this index for th e investigation of Quaternary sea-level changes.