Geophysical Delineation of Gold Mineralization Structures Using High-Resolution Ground Magnetic Data in Ilesha Schist Belt, Southwest Nigeria

Abstract Ground magnetic surveying was employed to investigate the subsurface geological structures hosting potential gold mineralization in the Itagunmodi area of Ilesha, southwestern Nigeria. A total of 595 data points were acquired across two study sites, along 12 traverses, using a Scintrex ENVI magnetometer at station intervals of 2–5 m. Base stations established proximal to each study site enabled repeated diurnal variation corrections at 30-minute intervals. Acquired data were subsequently filtered to remove cultural noise, excessive interference, and regional magnetic field contributions before processing. Residual magnetic data were processed using Oasis Montaj software, incorporating Reduction to the Equator (RTE) transformation, 3D Euler Deconvolution, and Source Parameter Imaging (SPI) to delineate the depth, orientation, and nature of subsurface magnetic sources. Residual magnetic field maps revealed intensity variations ranging from − 276.7 to 290.3 and − 263.9 to 232.5 nT for sites 1 and 2, respectively, while RTE map amplitudes ranged from − 446.1 to 367.7 and − 339.0 to 190.6 nT correspondingly. The 3D Euler Deconvolution analysis, constrained to a structural index of 0.5, delineated subsurface geological features consistent with joints, fractures, and faults, recognized conduits for gold mineralization trending in NW-SE, NE-SW, and N-S orientations. SPI analysis estimated depths to magnetic basement of 1.7–9.5 and 3.0–7.0 m for sites 1 and 2, respectively. The integrated interpretation confirms the efficacy of high-resolution ground magnetic methods for characterizing structurally controlled gold mineralization targets, providing a reliable geophysical survey to guide future exploration and resource evaluation in the Itagunmodi gold region.