INTEGRATED ANALYSIS OF AEROMAGNETIC, AERO-RADIOMETRIC AND GEOCHEMICAL DATA TO DELINEATE LITHIUM BEARING PEGMATITES IN KUJE SHEET 207 NORTH-CENTRAL, NIGERIA (Page 133-161)

Abstract

The increasing global demand for lithium, driven by its critical role in rechargeable batteries and renewable energy technologies, has intensified exploration in under-investigated regions of the Nigerian Basement Complex. Despite favourable geological conditions, the study area remains poorly explored for lithium mineralization. This study evaluates its mineralization potential using an integrated geophysical, geological and geochemical approach. High-resolution aeromagnetic and aero-radiometric datasets acquired were processed using derivative-based and radiometric filtering techniques. Aeromagnetic data enhanced by first vertical derivative, tilt derivative, analytic signal, and Centre for Exploration Targeting (CET) analysis reveal dominant NE-SW, NNE-SSW, and E-W trending structures consistent with regional Pan-African fabrics. Analytical signal maps define distinct magnetic domains, while Euler deconvolution indicates source depths ranging from shallow (<300 m) to deep-seated (>1,000 m), suggesting multi-level structural controls on mineralization. Radiometric analysis of potassium (K), equivalent thorium (eTh), and equivalent uranium (eU), including ternary and K/Th ratio maps, delineates zones of hydrothermal alteration spatially associated with structural features. Field mapping confirms lithologies dominated by migmatite, biotite gneiss, muscovite schist, and NE-SW trending pegmatite intrusions. Whole-rock geochemical data indicate silica-rich (51.03-75.34 wt.% SiO₂), aluminous (9.81–19.17 wt.% Al₂O₃), and variable alkali compositions, reflecting felsic to highly evolved melts with granitic affinity. Geochemical discrimination plots of Na₂O+K₂O+CaO vs. SiO₂, and A/NK vs. A/CNK) confirm a peraluminous granitic source, consistent with melts derived from crustal protoliths. Fractionation and mineralization potential were further evaluated using K/Rb vs Rb, K/Rb vs Cs, and Ta/(Ta+Nb) vs Mn/(Mn+Fe) plots, which indicate moderately evolved pegmatites belonging to the rare-metal LCT (Li-Cs-Ta) family. Trace element ratios (K/Rb <100) and enrichment patterns suggest significant fractionation and potential lithium mineralization. The integration of geophysical signatures with geochemical evidence highlights structurally controlled, fractionated pegmatite systems with significant lithium mineralization potential. These findings underscore the role of crustal evolution, magmatic differentiation, and structural controls in rare-metal enrichment.