PETROGENESIS AND GEOCHEMISTRY OF BIRIMIAN GRANITOIDS IN THE EASTERN KORHOGO BELT: GEODYNAMIC IMPLICATIONS

The Birimian formations of West Africa represent one of the most significant Paleoproterozoic provinces, hosting greenstone belts and granitoid intrusions with major metallogenic potential. In northern Cote d Ivoire, the eastern Korhogo belt remains poorly documented despite its economic importance. This study presents new petrographic and geochemical data on granodiorites and granites from the Korhogo belt to clarify their petrogenesis and tectonic setting. Petrographic observations reveal pervasive alteration, with plagioclase transformed into sericite, carbonates, and epidote, and ferromagnesian minerals destabilized into chlorite and epidote.Geochemical analyses show that the granitoids are calc alkaline, potassic, and I type, ranging from metaluminous to peraluminous compositions. Their trace element patterns are characterized by enrichment in large ion lithophile elements (LILE), negative Nb Ta anomalies, and strong fractionation of light rare earth elements (LREE), with variable europium anomalies. These features indicate a mixed crustal and mantle origin, consistent with subduction related magmatism in a continental arc setting. The pervasive hydrothermal alteration and greenschist facies metamorphism reflect post magmatic processes associated with regional deformation and fluid circulation. Overall, the Korhogo granitoids contribute to refining the geodynamic framework of the Baoule Mossi domain and highlight the metallogenic potential of Birimian terranes in Cote d Ivoire.