The expansion of artisanal gold mining is observed throughout the territory of Côte d'Ivoire. This is the case of the city of Toulépleu, in the west of the country. These artisanal activities, by opening quarries and wells, help at the way to describe lithologies and to understand the distribution of metals. It is the main objective of this study in Toulépleu which proceeds first by the description of the sites of artisanal mining activities, then by the study of the excavated material and horizons exposed finally the analysis of the samples on the X-ray Spectrometer. It appears that the associated gold mineralization is alluvial. The mineralized horizon is gravelly associated with quartz pebbles and rock fragments. These derived from the schists and granitoids of the Toulépleu-Ity furrow constituting the hills whose weathering products pile up successively in the valleys, concentrating gold by the same process. The brechic forms with subrounded of the pebbles and fragments of rocks indicate the result of a low hydrodynamics. The lihostratigraphic correlation shows, from the bottom to the surface, a succession of three horizons: clay, amalgam (gravelly) and clay-sandy. The mineralized horizon is thus preserved by the two clay horizons that frame it. Silicification decreases with depth especially in the mineralized zone which is also associated with zinc, silver, zirconium, sulfur and arsenic. Iron, calcium and manganese oxides evolve in contrast to silicification. Other metals like lead, vanadium, nickel, copper are distributed according to the sites and the depth of the wells.

The petrographic and geochemical study of the geological formations of Tabou and Grand-Béréby area located in SASCA domain (south-west of the Ivory Coast) show a strong foliated paragneisses. These gneisses are characterized by an alternation of dark layers of garnet-biotite-sillimanite and millimeter-thick leucocratic quartz-feldspar-cordierite bands. The mineralogical assembly thus described indicates a high grade metamorphism (granulite-facies). The major and traces elements made it possible to force the paragneisses protoliths. Thus this study shows that paragneisses are composed by greywackes and derived from source areas of felsic to intermediate composition. Their chondrite normalized REE patterns show a moderate LREE enrichment (LaN/YbN= 6,90-38,36) and a flat heavy rare earth patterns (HREE) This spectrum is almost identical to those of the Post-Archean average Australian Shale and Early Proterozoic Greywackes. Geochemical data also suggest that paragneisses are set up in a tectonic environment of active continental margin and continental island arc.