Geological and Geochemical Prospecting for Gold Mineralisation in Gnimi-Yaboghan, Southwestern Burkina Faso, Western Africa

Gold mineralization in Gnimi-Yaboghan, southwestern Burkina Faso, was investigated to enhance understanding of its geological context and exploration potential. Geological mapping at a 1:50,000 scale revealed amphibolite, schist, granitoid, and quartz veins. Mineralogical and geochemical analyses (XRF, ICP-MS) and fire assay techniques identified quartz, feldspar, mica, and accessory minerals. The granitoids were classified as calc-alkaline, peraluminous, and S-type, indicating formation in a subduction zone. A ternary diagram suggested a hydrothermal submarine origin for the quartz veins. Lithophile elements (K, Rb, Ba, Sr) showed a genetic link between quartz veins and metasedimentary rocks, with metamorphic fluids likely responsible for gold deposition. Gold content was very low in granitoids (<0.002 ppm) but reached up to 9.9 ppm in quartz veins, confirming them as the primary gold-bearing structures. This study supports previous findings that most gold in Burkina Faso is hosted in quartz veins and highlights the significance of hydrothermal processes in mineralization.