DEPTH TO MAGNETIC SOURCE ANALYSIS USING SOURCE PARAMETER IMAGING (SPI), ANALYTICAL DEPTH AND SPECTRAL DEPTH ESTIMATES

Four sheets of aeromagnetic data, which are the aeromagnetic map of Nsukka, Udi, Nkalagu, and Igunmale were obtained from the Nigerian Geological Survey Agency, these areas are within the Lower Benue trough and Anambra Basin, Southeast of Nigeria. Oasis Montaj 6.4.2, ArcGIS 10.2.2, Surfer 11, and Excel 2016 software, were used in the processing and interpretation of the aeromagnetic data obtained qualitatively and quantitatively. The results of the qualitative interpretation on application of Reduction to Equator (RTE) and analytical signal revealed the faults within the study area identified by the ripple like effects, sharpened boundaries, and gave simple shapes of the bodies responsible for the magnetic anomalies. The quantitative interpretation employing analytical depth and SPI depth, revealed depth ranges between 182.2 and 7800.5, 188.3 and 8068.3 respectively. Spectral depth estimates for the deep sources ranged from 0.83 to 6.17km with an average depth of 3.68km, while the shallow sources range in depth within 0.393 and 0.544km with an average depth of 0.465km. The contour map showing locations as well and depth map of the deeper sources revealed areas and their depths. These depth are relevant in that they are the depths to the magnetic basement, and are useful in exploration of water resources, minerals and hydrocarbon depending on the depth range been sort.

Keywords: Depth Analysis, Source Parameter Imaging, Analytical depth, Spectral depth estimates.