TITLE:
Factors Controlling Gold Mineralization at the Toéyoko Prospect (P17-P17 South), Bomboré District, Burkina Faso: A Structural and Host-Rock Lithogeochemical Approach
AUTHORS:
Madi Ouedraogo, Gounwendmanaghré Hubert Zongo, Pascal Ouiya, Ernest Gomdebziige Ouedraogo, Saga Sawadogo, Seta Naba
KEYWORDS:
Toéyoko Prospect, Orogenic Gold, Structural and Lithological Controls, Oriented Drill Core, Zr-Rich Granitoids
JOURNAL NAME:
Open Journal of Geology,
Vol.16 No.11,
November
13,
2026
ABSTRACT: Gold at the Toéyoko prospect (P17 and P17 South), south of the Bomboré deposit in Burkina Faso, is mainly hosted by silicified and deformed granitoids. To identify the factors controlling this mineralization, we combined 198 surface structural measurements, 2902 drill-core measurements from 43 diamond drill holes (848 measurements with a valid β angle) and geochemical analyses of 13 host-rock samples. At surface, the main foliation is subvertical and trends NNE-SSW (strike/dip 015/82); at depth, it dips 58˚ east (dip direction/dip 091/58) and is cut by NNW-SSE shear zones (075/61) that host quartz veins. At the scale of the permit, the foliation is fan-shaped. The angle between the mean foliation and shear-zone planes suggests mainly sinistral strike-slip movement (slip direction 355/17) during WNW-ESE shortening; because no paired S-C fabrics or kinematic indicators were measured, this sense of shear is provisional. The granitoids form two suites: a high-Sr/Y suite and a low-Al, Zr-rich (165 - 236 ppm) tonalitic to trondhjemitic suite; these names are provisional because alteration may have modified the major elements. Three of the four gold-bearing granitoids (5.1 - 8.6 g/t Au) belong to the Zr-rich suite, and all four are anomalous in As (>1000 ppm) and S (>0.4%). From this small, selected sample set, we propose a preliminary model in which transpression channeled fluids along the NNW-trending shear zones toward the contact between competent felsic intrusions and the surrounding metagabbros.