Biostratigraphic and Palaeoenvironmental Study of the Tob?ne Phosphatic Series (Western Senegal)

Moustapha DIAGNE, Mamadou Fall, Raphal SARR, Mouhamadou Bachir Diouf, Ndye Penda Dione

Abstract: The geological section of the phosphate quarry of Tobne associated with the boreholes of prospecting, carried out by miners, confirms the Tobnes lithostratigraphic and biostratigraphic settings. A lithostratigraphic analysis [1], [2] highlights three sedimentary formations, in agreement with previous results [3] From a biostratigraphic point of view, the planktonic microfauna highlighted E8 to E13 biozones in the phosphatic group, dating it to the early Lutetian to Bartonian age and helping to develop a more complete biozonation throughout the deposit. The pelagism index indicates an evolution of sedimentary environment between a slightly opened internal platform, favourable to detrital and siliceous deposits, and an intermediate platform more conducive to calcium phosphate deposits.

Keywords: Tobne, Taba, phosphate, lithostratigraphy, biostratigraphy