Analysis of Aeromagnetic Data of Ikwo and Environs, Southeastern Nigeria: A Mineral and Hydrocarbon Exploration Guide

Abstract

In the face of impending global energy crises, with demand for minerals and energy surpassing availability, the need to explore relatively frontier areas becomes imperative. In this study, high-resolution airborne magnetic data covering Ikwo and its adjacent areas were utilized to delineate possible mineral-bearing lineaments, determine depth to magnetic causative structures, and assess the sedimentary pile thicknesses with their implication for hydrocarbon and mineral exploration. The total magnetic intensity grid shows an acute change in magnetic intensity values, which reflect the subsurface geological environment. The second vertical derivative image indicates that the western, northwestern and southeastern-most parts of the area are most likely to possess abundant shallow magnetic bodies, which are most probably mineral deposits or igneous intrusive rocks. Ground-based electrical resistivity profiling and induced polarization methods were used to confirm the presence of these shallow bodies. Lineament analysis depicts NE–SW as the principal lineament orientation with minor E–W and N–S trends. The horizontal gradient magnitude revealed two depth models. Deeper bodies, attributed to intra-basement structures were marked as lying between 1.2 km to 4 km whereas shallow intrusive rocks occur within a depth range of 0.2 km to 1 km. The presence of numerous intrusive rocks and a relatively thin sedimentary thickness means that the area is unlikely to favor hydrocarbon accumulation. However, it appears viable and promising for solid mineral exploration.