The Senegalo - Malian fault: Control on gold mineralization, sedimentological and structural propriéty the case of Gounkoto ore deposit in the Kenieba inlier (mali)

The Gounkoto gold mine is located in the Paleo-Proterozoic terrane of Dalema Series (or Kofi) in Kédougou Kéniéba inlier some 377 km west of the capital, Bamako (Mali). Kofi Series consists of sedimentary rocks intruded by a volcanic complex and hypo-volcanic.The entire series of Kofi was affected by the Eburnean orogeny (2400-1600 Ma) with 3 successive phase deformations: the collisional phase D1 or tangentially affected sediments of lower Birimian B1, and that of the upper Birimian B2, transpressional phase D2 is responsible for deformation of large regional structures such as the Senegalese- Malian shear zone (SMSZ) and finally the transtensive dexteral stage D3 responsible for reactivation of the D2 phase. Tectonic analysis of the career Gounkoto and its mineralized zones, allowed to highlight a local evolution of paleo-stress states based on the geometry of the main fault relay:  Main Zone 1 (MZ 1): a compression along a WNW-ESE orientation with extensive component and shear.  Main Zone 2 (MZ2): a compression along a WNW-ESE with a slight shear.  Main Zone 3 (MZ3): a compression direction a WNW-ESE with extensive component.  MZ4 and P64E : a pure extension NNE –SSE The sinistral movement of the Senegalo-Malian fault suggests that the secondary structure mineralized studied in this work, played by the same sinister game. This work has validated this design, both a map view with the discontinuity of the share series and the other of the fault zone and also from the perspective of tectonic analysis. The study paleo-strain tensor is used to specify locally, in areas prone extension mineralization. The petrographic sequence remains basic, but in good agreement with previous work linking the gold mineralization with mineral phases observed in thin sections and MEB. KEYWORDS: Kedougou – Keniéba inlier, tectonics, stress tensor, mineralization, stratigraphy, sedimentology, gold.