Abstract

2-D Spectral Analysis of aeromagnetic anomalies over parts of Monguno and environs, northeastern Nigeria was carried out to determine the depth to basement, establish the basement topography and determine the temperature at depths in the area. Data enhancement was carried out to delineate residual features and the more intense anomalies relative to the strong regional gradients. Typical techniques applied were computations of reduction to pole, trend surface analysis, and a number of filtering processes. Results of the 2-D spectral analysis of the aeromagnetic data revealed a two depth source model. The depth to the deeper magnetic source bodies ranges from 1.22 to 3.14 km, with an average depth of 2.341 km. This layer may be attributed to magnetic rocks of the basement, lateral variations in basement susceptibilities and intra- basement features like faults and fractures. The shallower magnetic sources range in depth from 0.12 to 0.93 km, with an average depth of 0.572 km and could be attributed to near surface magnetic sources, which are magnetic rocks that intruded into the sedimentary formations. Based on the computed average sediment thickness obtained in this study together with the temperature at depths in the area, some parts of the study area have been demarcated for detail hydrocarbon exploration in-line with the renewed interest in hydrocarbon exploration in the basin.

Keywords: Aeromagnetic anomalies; basement depth; Chad Basin; Monguno; spectral analysis