GEOLOGY AND GEOCHEMICAL EVALUATION OF GOLD POTENTIAL IN KORO, PART OF PATIGI SHEET 204SE, NIGERIA

Abstract

This study evaluates the gold mineralization potential of the Koro area (Patigi Sheet 204SE), Kwara State, Nigeria, using an integrated approach involving airborne geophysical interpretation, geological mapping, petrographic analysis, and geochemical investigation. The study area lies within the northern extension of the Egbe-Isanlu Schist Belt of the Nigerian Basement Complex, a region recognized for structurally controlled mesothermal gold systems but relatively underexplored in this segment. Airborn-magnetic and radiometric datasets were processed using first vertical derivative, tilt derivative, analytic signal, and horizontal gradient techniques to delineate lithological boundaries, structural fabrics, and hydrothermal alteration zones. Results from the geophysical analysis reveal dominant NE-SW to NNE SSW structural trends, intersected by NW-SE cross-cutting faults that define potential pathways for mineralizing fluids. Geological mapping at a scale of 1:12,500 identified migmatitic gneiss, granites, amphibolites, and quartz veins, with evidence of deformation including shearing, fracturing, and veining. Petrographic analysis confirms mineral assemblages dominated by quartz, feldspars, biotite, and amphibole, alongside microstructural features indicative of tectono-metamorphic evolution. A systematic soil geochemical survey conducted on a 200m X 200m grid, with samples analyzed using ICP-MS, indicates generally low background gold concentrations but highlights discreteanomalous zones. Gold and associated pathfinder elements, such as arsenic, copper, lead, and antimony, show positive correlations and spatial clustering at NW-SE structural intersections, suggesting structurally controlled mineralization. The integration of geophysical, geological, and geochemical datasets confirms the presence of a structurally controlled hydrothermal gold system within the study area. The delineated anomalies and structural targets provide a strong basis for further exploration, including detailed infill geochemical sampling, trenching, ground geophysics, and drilling to evaluate subsurface continuity and economic potential.