Application of Induced Polarization Geophysical Techniques for Targeting Potential Concealed Pegmatite-Hosted Lithium Mineralization in Part of Keffi Sheet 208SW, North-Central Nigeria

The global energy transition has created a substantial increase in lithium demand, prompting intensified exploration for pegmatite-hosted deposits, with particular attention directed toward Nigeria's underexplored pegmatite belts. This study applies induced polarization (IP) geophysical techniques to target potential concealed pegmatite-hosted lithium mineralization beneath thick lateritic overburden in the Keffi Sheet 208SW area of Nasarawa State, North-Central Nigeria. The research employed an integrated methodological approach combining preliminary geological reconnaissance, systematic survey design, and comprehensive IP data acquisition using the dipole-dipole array configuration with 25 m electrode spacing. Six profile lines were established across two target areas (Area A: four profiles; Area B: two profiles), with line spacings of 100 m and station spacings of 20 m oriented perpendicular to the dominant NE-SW structural trend. Data processing involved apparent resistivity and chargeability calculations, followed by 2D inversion using RES2DINV to generate true resistivity and chargeability models. The results revealed distinct high-resistivity anomalies (ranging from 1,000 to >10,000 Ω·m) with low-to-moderate chargeability signatures, characteristic of pegmatite bodies, contrasting with the surrounding schists and gneisses which exhibited lower resistivity (100 - 500 Ω·m) and higher chargeability (5 - 15 mV/V) due to disseminated sulfides and clay minerals. The integrated interpretation identified five priority targets characterized by high-resistivity zones associated with structural lineaments, particularly at intersections of NE-SW and NW-SE trending fractures. The geoelectric approach yielded a database of interpreted coordinates, lateral extents, and estimated depths for potential lithium-bearing pegmatite zones. This study demonstrates that IP techniques, when integrated with structural analysis, provide a robust and cost-effective methodology for detecting concealed pegmatite mineralization in thickly covered terrains. The findings contribute to the strategic development of Nigeria's lithium resources and offer a replicable exploration framework for analogous geological settings across West Africa. However, we emphasize that drilling verification is essential to confirm the presence of lithium mineralization.