This paper aims to show the relationships between hydrothermal alteration, deformation and gold mineralization in the main area of the Kiaka deposit. The Kiaka gold deposit is located in the South-central of Burkina Faso in the Tenkodogo volcano-sedimentary belt. Mineralization is primarily hosted by amphibolite, mylonitized quartz microdiorite and meta-sediment. The combination of petrographic, metallographic and geochemical analysis along with structural deformation of the orebody allowed us to distinguish the three main stages of hydrothermal alteration in the Kiaka gold deposit. (i) The first stage is characterized by ductile deformation which induces potassic- and LILE-rich alteration with crystallization of disseminated pyrrhotite. (ii) The second stage corresponds to chloritization and is associated with a brittle-ductile deformation and retrograde metamorphism. A second generation of disseminated pyrrhotite and a few pyrite and chalcopyrite crystallized during this event. Pyrrhotite also fills veins. (iii) The third alteration stage is characterized by a significant carbonation and concurrent with a brittle deformation. It is accompanied locally by a high-grade gold mineralization (up to 29 g/t).

Gold Deposit, Hydrothermal Alteration, Deformation, Geochemistry