Geological Processes of Lithium Mineralization in Pegmatites Around Madubi, North-Central Nigeria

Abstract

The study investigates the geological processes of lithium mineralization in pegmatites around Madubi, North-Central Nigeria. The size of the total area mapped is 33km² and falls within latitude 8°57′0.18″N to 9°0′24.26″N and longitude 7°49′35.08″E to 7°52′21.58″E. Geological field mapping and geochemical analyses were employed to evaluate the lithological units, structural framework and mineralogical characteristics controlling lithium enrichment. The study area, which lies within the Nigerian Basement Complex, is underlain by schist, medium-to coarse-grained granites and pegmatites that intrude the older lithologies. Geochemical analysis, including X-ray fluorescence (XRF) and flame photometry, indicates that the pegmatites are highly siliceous (SiO₂ averaging 70 –75wt.%), rich in alkalis (Na₂O + K₂O > 8wt.%), and depleted in mafic components (Fe₂O₃, MgO, TiO₂). Lithium oxide (Li₂O) concentrations range from 0.11 to 0.67wt.%, with the highest enrichment in samples TJ2a–TJ2f. These values suggest moderate lithium mineralization potential, consistent with lithium–cesium–tantalum (LCT)-type pegmatites derived from fractionated granitic melts. The pegmatite bodies show distinct internal zoning and are structurally controlled by fractures trending mainly NNW - SSE and NNE - SSW. Generally, the Madubi pegmatites are products of residual granitic magmatism and show promising lithium enrichment, although the analysis of the rock samples taken at the surface shows a relatively low in Li₂O concentration. However, sampling at deeper depths may give a higher Li₂O concentration.