Application of 2-D Spectral Inversion and 3-D Standard Euler Deconvolution of Magnetic Anomalies over Subsurface Structures in Ilorin, Nigeria

Abstract

The utilization of high-resolution aeromagnetic data in the geological interpretation of the basement complex of Ilorin has provided crucial insights into the spatial distribution and characteristics of magnetic anomalies, aiding in the delineation of structural discontinuities and the estimation of depths to anomalous bodies. This study explores the relationship between magnetic responses and geological features by employing 2-D spectral inversion and 3-D Standard Euler Deconvolution methods for depth estimation. Analysis of the aeromagnetic data reveals distinct magnetic zones within the study area, with varying intensities indicative of different lithological units such as migmatite, quartzite, biotite gneiss, and silicified quartz. Linear and curvilinear magnetic anomalies with sharp gradients are identified, suggesting the presence of structural features like faults and fractures possibly resulting from tectonic activity. The depth estimates to anomalous magnetic bodies range from 0.20 km to 1.10 km, with two-layer depth models (h1 and h2) representing shallower magnetic sources and the magnetic basement rock, respectively. The depth to the basement complex varies spatially, with the shallowest basement observed in the southern part of Ilorin and thicker sediment piles in the southwestern part. Overall, the estimated depths to basement range between 0.250 km and 0.480 km is characterized as the shallow depth for mineralization area. The findings identified faults and fractures that are significant for mineral potential assessment and geological mapping of the region.