Combining Aeromagnetic, Radiometric and Remote Sensing Datasets to Reveal Subsurface Structures in Ikole-Itapaji Area, Southwestern Nigeria: An Interim Report

Abstract

Despite the growing application of geophysical and remote sensing techniques in mineral exploration, many studies in Precambrian basement terrains of Southwestern Nigeria lack an integrated approach that combines aeromagnetic, radiometric, and satellite datasets for robust structural and mineralization targeting. This study addresses this gap by integrating high-resolution aeromagnetic, radiometric, and Landsat 8 OLI imagery to delineate lithological variations, structural trends, and mineralization zones within the Ikole–Itapaji area. Landsat 8 OLI/TIRS imagery (scene LC09_L1TP_190054_20250211) obtained from the USGS Earth Explorer platform was used for lithological and structural mapping. High-resolution airborne aeromagnetic and gamma-ray spectrometric data covering the Ado-Ekiti Sheet 244 and Ikole Sheet 245, with the following parameters: terrain clearance of 80 m, flight line spacing of 150 m, and tie line spacing of 1500 m.  were acquired by the Nigerian Geological Survey Agency in 2023 and processed using Geosoft Oasis Montaj 8.4 (HJ). The methodology involved IGRF correction of Total Magnetic Intensity (TMI) data, polynomial filtering for regional–residual separation, and Reduction to the Equator (RTE) to enhance anomaly positioning. Analytical Signal and Euler deconvolution were applied to delineate structural boundaries and estimate source depths, while radiometric processing and potassium deviation mapping highlighted alteration zones. Remote sensing analysis included principal component analysis (PCA) and automated lineament extraction. Results reveal dominant NE–SW and NW–SE structural trends, with high lineament density concentrated along the Itapaji–Bolorunduro axis. Euler solutions indicate shallow, structurally controlled sources at depths of approximately 0.5–2.5 km. Radiometric analysis shows significant potassium enrichment, indicating hydrothermal alteration. Mineralization is interpreted as structurally controlled hydrothermal mineralization associated with quartz veins and pegmatitic intrusions. The Itapaji–Bolorunduro corridor is identified as the most prospective zone due to the convergence of favorable structures, shallow mineralization depth, and strong alteration signatures.