Abstract

This research aims to estimate the depth of basement rocks in the Guzabure and Gudumbali areas with longitude (12.3° to 13.0° N) and latitude (12.3° to 13.3° E) within the Nigerian sector of the Chad basin using aeromagnetic data. The quantitative data interpretation employed the spectral analysis approach and Oasis Montaj 6.4.2 software. Minimum curvature was applied in gridding the data to produce a total magnetic field intensity (TMI) contour map, while first-order polynomial fitting was used to produce a residual contour map from the TMI contour map. The total magnetic intensity (TMI) contour map ranges from -75.4 to 63.9 nanoTesla (nT) while the residual intensity varies from -74.4 to 64.7 nT. The depth results from spectral analysis showed two depths of magnetic sources, the shallower magnetic source bodies ranging from 0.959 to 1.137 km with an average depth of 0.915 km and the deeper magnetic source bodies ranging from 1.918 to 4.195 km with an average depth of 2.969 km bodies. The shallower depth magnetic sources layer may be attributed to the near-surface magnetic rocks that intruded into the sedimentary formations while the deeper depth magnetic source layer could be attributed to basement magnetic rocks, intra-basement features like fractures and faults, and lateral variations in basement susceptibilities. Based on the average computed sedimentary thickness obtained in this research, the possibility of solid mineral recourses and hydrocarbon accumulation cannot be ruled out if other prerequisites for hydrocarbon generation are satisfied.

Key words: Spectral analysis, basement rocks, magnetic anomalies, Gudumbali, Guzabure.