Metallogeny of cobalt in the ore-belt of Bou Azzer - El Graara

The Co-Ni arsenide ore deposits of the Bou Azzer district in Morocco are represented by specific multistage mineralization which has been formed in different geodynamic settings that resulted in changes of tectonic regime, magmatism and features of the ore-forming processes. Several Co-Ni-As-Au-Ag mines of the Bou Azzer district are in operation now. Co-Ni arsenide mineralization is structurally controlled and located along the contacts of Neoproterozoic peridotite and quartz diorite intrusions and Precambrian volcanic rocks. Ore minerals in quartz-carbonate veins are represented by arsenides, sulfoarsenides, and sulfides. Ore veins are mainly composed of chalcopyrite, bornite, chalcocite, Cu-Zn sulfides, pyrite, pyrrhotite, sphalerite, and tetrahedrite. Cobalt-rich ores predominate in most deposits of the Bou-Azzer district. The main ore minerals are arsenides including skutterudite (CoAs3), safflorite (CoAs2), löellingite (FeAs2), nickeline (NiAs), rammelsbergite (NiAs2), Ni-Co arsenides, and sulfoarsenides (arsenopyrite and gersdorffite).