Petrography, Geochemistry, and Lithium Exploration Potential of Pan-African Granitoids from Pamsi Area (Northern Cameroon Domain)

Abstract

This study presents an integrated petrographic and geochemical investigation of granitoid and metamorphic ‎rocks from the Pamsi locality in the North Cameroon Domain of the Pan-African Fold Belt. Field observations, ‎microscopic analysis, and whole-rock geochemistry reveal five main lithological units: amphibole-biotite ‎granite, leucogranite, granodiorite, orthogneiss, and amphibolite. These rocks form a calc-alkaline suite ranging ‎from syeno-diorite to granite, classified as I-type, sub-alkaline, potassic to hyperpotassic, and predominantly ‎peraluminous to metaluminous. Geochemical signatures include strong LREE enrichment, negative Eu ‎anomalies in most samples, and multi-element patterns showing negative Ta-Nb, Sr, and Ti anomalies with ‎positive Th, Zr, and U anomalies, characteristic of differentiated magmas from mixed crustal-mantle sources. ‎Tectonic discrimination diagrams indicate volcanic arc to syn-collisional settings consistent with Pan-African ‎orogenesis. Pathfinder element analyses reveal preliminary indications of lithium exploration potential, with ‎samples N11 and N51 showing notable cesium enrichment (8.80–11.30 ppm) and elevated Cs/Rb ratios. Based ‎on established geochemical correlations—and pending direct lithium measurements—estimated lithium ‎contents of 200–800 ppm are proposed as preliminary targets for further investigation. These results highlight ‎the Pamsi area as a promising prospect for lithium mineralization associated with evolved pegmatitic systems, ‎warranting systematic follow-up studies‎.