Genesis of Graphite Mineralization in the Kambale Graphite Deposit, Wa-Lawra Belt, Ghana: Evidence from Petrography, Geochemistry, and Stable Carbon Isotopes

Graphite is a critical raw material for emerging energy technologies, yet the origin of many Paleoproterozoic graphite deposits remains poorly constrained. This study presents the first integrated investigation of graphite mineralization at the Kambale Graphite Deposit in the Wa–Lawra Belt of northwestern Ghana, combining field observations, petrographic, SEM-BSE/EDX, whole-rock geochemistry, total carbon content (%C), and stable carbon isotope (δ13C) analyses. Graphite occurs predominantly as fine crystalline flakes associated with quartz and muscovite and aligned parallel to the schistosity, consistent with syn-metamorphic recrystallization and deformation-assisted grain coarsening. Accessory pyrrhotite is closely associated with graphite within graphite schists. Graphite mineralization occurs within graphitic metasedimentary units, whereas the associated gneisses and metagranodiorite are interpreted as granitoid-derived meta-igneous rocks. Trace-element and REE characteristics, including LREE enrichment and negative Nb-Ta-Ti anomalies, indicate that the gneisses and metagranodiorite were derived from evolved continental crust and originated from granitic to granodioritic protoliths in a continental arc setting. The graphite schists contain 0.58–17.29%C, while their stable carbon isotope compositions (δ13C = −31.83‰ to −24.33‰ VPDB) support an organic-derived carbon source. The mineral assemblages are consistent with lower amphibolite-facies metamorphism, which facilitated the graphitization and recrystallization of sedimentary organic carbon. The deposit formed through deposition of carbonaceous sediments followed by Eburnean metamorphism and deformation, providing a framework for graphite exploration in the West African Craton.