Situated on the northern edge of the West African craton, the Bleida orebodies are located on an inactive continental margin along which are preserved ophiolites of Upper Proterozoic age. The copper deposits (chalcopyrite, bornite, pyrite) are stratiform distal massive sulfide deposits whose position is controlled by both the sedimentation of shales and an acid volcanism which follows a more important basic volcanism. Pan-African deformation (650-600 m.y.) has determined the actual geometry of the cupriferous lenses although it has not remobilized the sulfides out of their original carrier beds. The known reserves amount to about 200,000 tons of copper metal, mostly contained in high-grade ore (8% Cu).