Mapping of Lineaments Structures for Groundwater Study using Aeromagnetic Data: Case Study of a part of Ilorin and its Adjoining Areas, Central Nigeria

Abstract

A study was conducted on the Basement Complex rocks around Ilorin, located in southwestern Nigeria, to map lineaments and understand the structural elements influencing the region’s hydrogeology. The investigation combined aeromagnetic data analysis with existing geological information from the area. Both qualitative and quantitative approaches were applied using Oasis Montaj™ software to interpret the IGRF-corrected aeromagnetic dataset. Depth estimation to magnetic sources was carried out through three-dimensional (3D) Euler deconvolution, which provided insights into source geometry, magnetic characteristics, and subsurface structural configurations based on structural indices. The integration of aeromagnetic interpretations with geological data enabled the extraction and evaluation of major lineaments and fault systems. The analysis revealed that many of the delineated structural features align with river channels depicted on geological maps, suggesting a strong structural influence on the drainage pattern. Predominant lineament orientations are NE–SW, with subordinate NW–SE trends, reflecting conjugate strike-slip fault systems associated with the Pan-African tectonic events in Nigeria. These structures display both dextral and sinistral movements, cross-cutting earlier Pan-African fabrics.