Delineation of the subsurface geological structures of Omu-Aran area, south-western Nigeria, using aeromagnetic data

Abstract

Omu-Aran area is characterized by mining activities to exploit the valuable mineralization there. These facts motivated the present work to evaluate the factors controlling the mineralization in the study area using aeromagnetic data obtained from the Nigerian Geological survey Agency. The data was processed and interpreted with the mean of delineating subsurface geological structures around Omu-Aran in Kwara State, South-western Nigeria. Data enhancement methods was performed on the aeromagnetic map using Regional Residual Separation of the total field anomalies map; horizontal gradient enhanced and International Geomagnetic Reference Field (IGRS) removed; reduced to the pole magnetic shaded relief image was carried out; Magnetic vertical gradient calculated, Magnetic horizontal gradient measured and Analytical signal map was constructed using some computer aided packages. The interpreted map enabled delineation of various subsurface geological structures such as the rock contacts, fractured and faulted areas.