Spectral Analysis of the Residual Magnetic Anomalies Overpategi and Egbako Area of the of the Mddle Niger Basin, Nigeria

Abstract

Statistical spectral analysis of theresidual magnetic field was employedto determine the depth to magnetic basement rocks withinPategi and Egbako areas which is part of the lower Middle Niger basin. The study area lies within latitudes 8.30⁰ and 9.30⁰ North and longitudes 5.30⁰ and 6.00⁰ East. For the purpose of this analysis, the study area was divided into 15 rectangular sections. The spectral analysis reveals two prominent layers; the first layer depth varies from 0.28km to 0.89km with an average value of 0.59km while the second layer depth varies from 1.55km to 4.70km.The first layer is attributed to lateritic ironstone,Ferruginoussandstone and effect of the surrounding basement rocks while the second is attributed to magnetic rocks intruded into the basement surface, lateral discontinuities in basement susceptibility and intra basement features such as faults and fractures. The second layerrepresents the average thickness of the sedimentary formation overlying the basement complex within the Pategi and Egbako areas of the Middle Niger basin. This depth increases thepossibility of hydrocarbon potential.

Keywords: spectral depth, buried magnetic rocks, magnetic data