Electrical imaging of lateritic weathering mantles over granitic and metamorphic basement of eastern Senegal, West Africa

摘要: Abstract The electrical properties of several tens metres lateritic weathering mantle were investigated by using resistivity tomography (ERT) in two basement areas eastern Senegal. field survey was conducted along profiles providing continuous coverage. Colour-modulated pseudosections apparent vs. pseudo-depth plotted for all lines, giving an approximate image the subsurface structure. In area underlain granitic basement, pseudosection suggests a very inhomogeneous weathered layer which changes more rapidly than thickness. second area, schists, lateral are less pronounced those area. Interpretation 2D Wenner data yielded considerable detail about regolith, even without pit information. both areas, near-surface topsoil comprising undersaturated material is highly resistive. intermediate with low resistivities (e.g., 20–100 Ωm) contains clays including small quantities water. third, resistive reflects basement. Comparison ERT results information shows general agreement and that can be used as fast efficient exploration tool to map thick tropical hard rock geology.