NEW PETROGRAPHIC DATA FROM THE EASTERN PART OF THE YAOURÉ VOLCANO-PLUTONO-SEDIMENTARY GREENSTONE BELT (CENTRAL CÔTE D’IVOIRE, WEST AFRICA)

This petrographic study conducted in the eastern part of the Yaouré trough aims to characterize lithological diversity and to specify the mineralogical and textural features of the geological units. The methodology combines field observations (maping and macroscopic description of outcrops) with petrographic analyses in thin sections, allowing the identification of mineralogical composition, textures, and alterations. The results reveal a wide variety of volcanic rocks (dacites, basaltic andesites, pillow lavas, pyroclastics), metasedimentary rocks (quartzites, cherts, sandstones, carbonate tuffs, tourmaline bearing chloritoschists, cataclasites), and intrusive rocks (microgranites, granites, gabbros, diorites, granodiorites). Microscopic observations highlight a notable abundance of carbonate phases, associated with chloritization, sericitization, and silicification. These hydrothermal alterations, often linked to episodes of fracturing and fluid circulation, indicate an environment favorable to gold mineralization. The observed lithological organization, marked by effusive and explosive volcanic sequences intruded by late plutonic bodies, fits within the Birimian geological framework. It confirms the inclusion of the studied area in this domain and emphasizes a context conducive to the circulation of mineralizing fluids and the formation of gold deposits.