Geology And Geochemistry Of Rare Earth Element (Ree)-Bearing Pegmatites Around Gwon-Gwon, Wamba Area, North-Central Nigeria

Abstract

Rare earth element (REE)-bearing pegmatites are important exploration targets because they can concentrate critical metals during the final stages of granitic differentiation. This study evaluates the geology, structural controls, and whole-rock geochemistry of pegmatites around Gwon-Gwon, Wamba, North-Central Nigeria. Detailed mapping, structural measurements, and geochemical analyses were undertaken on eighteen representative pegmatite samples. The pegmatites occur mainly as discordant veins, ridge-forming bodies, and lenticular intrusions within migmatitic gneisses and leucogranites, with dominant NE–SW, ENE–WSW, N–S and subordinate NW–SE structural trends. Major-element data show decreasing MgO, Fe₂O₃, CaO, TiO₂ and P₂O₅ with increasing SiO₂, indicating progressive fractional crystallization. A/CNK–A/NK relations indicate predominantly metaluminous to weakly peraluminous compositions. Trace-element data show enrichment in Rb, Cs, Nb, Ta, Sn and selected REEs, while decreasing K/Rb ratios with increasing Rb indicate advanced magmatic differentiation. Tectonomagmatic discrimination places most samples in a late- to post-orogenic setting related to Pan-African granitic magmatism. The integrated evidence indicates that the pegmatites represent evolved residual melts emplaced along pre-existing structural discontinuities and possess significant rare-metal fertility, warranting further mineralogical and exploration investigation.