Aeromagnetic Data Analysis for Mineral Prospectivity Mapping in Oji-River and Awgu Areas, Enugu State

The sedimentary and basement contact zones of Enugu State remain underexplored for solid mineral resources despite geological indicators of potential mineralisation. This study analyses aeromagnetic data to produce mineral prospectivity maps for the Oji-River and Awgu areas of Enugu State, with focus on identifying structural controls on mineralisation and delineating high-potential zones. High-resolution aeromagnetic data from the NGSA national airborne geophysical survey were acquired and processed with standard techniques including reduction to equator, first vertical derivative, analytic signal, and source parameter imaging. Magnetic susceptibility contrasts were used to infer lithological variations and identify intrusive bodies that may serve as heat sources for hydrothermal mineralisation. Magnetic anomaly trends are predominantly northeast-southwest, reflecting the structural fabric of the Benue Trough system. Positive analytic signal anomalies collocated with mapped structural lineaments are interpreted as zones of mineralised veins or contact metasomatic deposits. Source parameter imaging constrains magnetic source depths from 0.5 km to approximately 3.8 km, with shallow sources likely representing near-surface mineralised structures. Three prospectivity zones are classified as high, moderate, and low priority based on the spatial coincidence of magnetic anomalies, lineament density, and proximity to known mineralised occurrences. These zones are recommended for follow-up geological and geochemical verification. This study advances the application of aeromagnetics in targeting mineral exploration in sedimentary and basement terrane transitions in Enugu State and southeastern Nigeria broadly.

Keywords: aeromagnetics, mineral prospectivity, source parameter imaging, analytic signal, Enugu State