Joint Application of Drilling, Geophysical, and Remote Sensing Methods to Characterize Uncertainties on the Geometry of Phosphate Deposits (Senegal)

The Paleocene and Middle Eocene in the Senegalo-Mauritanian sedimentary basin contain significant phosphate resources. The exploration and evaluation of these strategic resources are hindered by uncertainties about the geometry of the layers. The main sources of uncertainty are tectonic movements and post-depositional sedimentation phenomena. Given the high cost of drilling and the need for sufficient precision, remote sensing data have been integrated into the combination of geophysical methods (electrical tomography and seismic refraction) and core drilling to reduce the main geological uncertainty. This combination allowed the “overburden–ore” and “ore–wall” interfaces to be more accurately defined. Application of the method allowed optimizing the planning and the number of drill holes and consequently reduced the exploration costs significantly.