Implementing Digital Edge Enhancers on Improved High-Resolution Aeromagnetic Signals for Structural-Depth Analysis around the Middle Benue Trough, Nigeria

Abstract

Digital edge detector operations using magnetic derivatives in conjunction with spectra depth analysis were performed on high-resolution aeromagnetic signals to enhance the delineation and interpretation of depth, structural, and intrasedimentary features within the Middle Benue Trough (MBT) of North Central Nigeria, which could serve as a guide for mineral exploration. The derivatives revealed high-amplitude and short-wavelength anomalies over areas underlain by crystalline basement complexes, major volcanic zones, and aggregates of intrasedimentary volcanic and plutonic rocks. Geologic lineaments trending predominantly NE–SW and NW–SE, as well as minor trends of E–W and N–S, suggest that the area has undergone differential stress regimes across geologic time. The spectral depth analysis indicates a two-source depth model. The deep depth ranges from 1.9 to 6.1 km with an average of 3.9 km, whereas the shallow depth ranges between 0.3 and 1.9 km with an average of 0.8 km and is found to emanate from magnetic signals of post-Cretaceous near-surface igneous intrusions as well as other magnetized bodies embedded within the sediments. The spatial distribution of various hydrothermal minerals such as lead–zinc–barite deposits, as well as salt mineralization, is associated with the widespread Tertiary–recent magmatism and governed by pre-existing tectonic structures in the region.