Metallotectic Context of the Mineralization of the Tondabo Gold Prospect (Brobo, Center of Côte d’Ivoire, West Africa)

Abstract

The gold mineralization of the Tondabo prospect, located in the northern part of the Oumé-Toumodi-Fettêkro greenstone belt, is mainly hosted in the rhyodacite and to a lesser extent in the mafic volcanics (volcanic lavas and volcanoclastites). These rocks were affected by a hydrothermal alteration marked by quartz veins and veinlets associated with crystals of carbonates, sericite, epidote and sulfides. This hydrothermal alteration induced a pervasive alteration of the surrounding bodies with silicification, chloritization, carbonation and sericitization of the feldspars. The metalliferous paragenesis contains an abundant pyrite, with rare pyrrhotite and chalcopyrite. This mineralization indicates that the Tondabo gold prospect exhibits lithological control. The mineralized deposits are generally affected by a S1 schistosity oriented mainly N000-010˚ and minority N040-050˚ with a general dip of 60˚-80˚ to the West; however with rare N-S orientations with a dip of 60˚-80˚ to the East. The drilling intervals show that the highest gold contents are linked to the quartz-carbonates veins and veinlets, which are located in the highly deformed zones, characterizing local shear zones.