The Japan International Cooperation Agency (JICA) and the Metal Mining Agency of Japan (MMAJ which reorganized the Japan Oil, Gas and Metals National Corporation) conducted a mineral exploration project surround the Baoule and Banifing Basin, the republic of Mali for eleven years since 1991.
Lateritic deep weathering is well developed throughout the project area. We estimated degree of lateritization by multi-element analysis and selected in situ geochemical anomalies by using regolith-landform map. Because Arsenic has close affinity for Fe-oxides, we used As/V ratio to distinguish arsenic enrichment derived from gold mineralization. As a result of pitting and RAB drilling conducted in the area where in situ Au and As/V ratio were overlapped, two gold mineralization zones were delineated.
The Siriba-Sobara gold mineralization zone is hosted in two mica granite and distributes 100-350m ×900m with NW-SE direction. This mineralization accompanies with Bi, As and W. Another Batouba gold mineralization zone is hosted in both meta-sediment and granite. This mineralization is heterogeneous and accompanies with Bi, Cu and Sn.
