2-D Spectral Analysis of Aeromagnetic Anomalies over Parts of Bida Basin, Nigeria

Abstract

The average depth of magnetic sources was estimated in some portions of the Bida Basin. A 2-D spectral analysis of aeromagnetic anomalies over six aeromagnetic map sheets, each spanning an area of ½° x ½° on a scale of 1:100,000, was carried out. To identify residual features and draw attention to the more intense anomalies in comparison to the strong regional gradients, data augmentation techniques were used. Adopted techniques include various filtering approaches, trend surface analysis, and computations reducing to the equator. The result shows the two-depth source model of the part of the basin with an average depth of the deeper magnetic sources at 3.26 km, which corresponded to the magnetic basement surface. This layer may be associated with intra-basement characteristics including faults and fractures, lateral changes in basement susceptibilities, and magnetic rocks found in the basement. There are magnetic intrusive bodies within the sediments, as evidenced by the average depth of 1.22 km and a range of 0.68 km to 2.32 km for the shallower magnetic sources. The magnetic source's average depth of 3.26 km to the basement indicates a sufficient sedimentary thickness for potential hydrocarbon accumulation. The undulating nature of the basement surface may create traps for hydrocarbons, suggesting that the possibility of hydrocarbon accumulation cannot be ruled out.