Integrated Geophysical Assessment of Gold Prospectivity in Southwestern Nigeria: Induced Polarisation, Electrical Resistivity Tomography, Airborne Radiometrics and Aeromagnetics

Gold exploration within the Ilesha–Ife schist belt of southwestern Nigeria increasingly combines geophysical datasets, yet the evidence connecting measured physical-property contrasts to economically significant gold mineralisation remains uneven. This critical narrative review assesses the geological basis, diagnostic value and principal uncertainties of induced polarisation, electrical resistivity tomography, airborne gamma-ray spectrometry and aeromagnetic interpretation. Peer-reviewed regional investigations and foundational geophysical literature published between 1986 and 24 August 2026 were appraised for geological relevance, measurement validity, inversion uncertainty and independent mineralogical or geochemical confirmation. The strongest regional evidence establishes structurally controlled quartz–carbonate vein mineralisation, altered basement hosts and associated placer occurrences. Aeromagnetic and radiometric studies consistently identify structural fabrics, lithological discontinuities and possible alteration footprints; nevertheless, a magnetic lineament or potassium anomaly is not itself a gold occurrence. Ground resistivity and induced-polarisation profiles sharpen shallow targets by imaging electrical contrasts, but chargeability may reflect sulphides unrelated to gold, while conductive weathered regolith can mimic alteration or fracture zones. Several published prospectivity maps correlate with known workings, although non-independent validation, heterogeneous survey resolutions and incomplete assays constrain estimates of predictive performance. An integrated interpretation is most defensible when geological mapping and surface geochemistry anchor regional airborne screening, joint electrical inversion constrains target geometry, and independently sampled trenches or boreholes test mineralisation. The review proposes an evidence hierarchy separating physical anomalies, mineral-system plausibility and assay-confirmed resources, with explicit attention to uncertainty propagation, spatial cross-validation and environmental safeguards. Available methods can improve exploration prioritisation, but their combined use has not yet established a generally transferable or independently validated probability of economic gold occurrence across southwestern Nigeria.