Determination of Geothermal Potential of Lower Sokoto Basin, NorthWestern Nigeria Using High Resolution Aeromagnetic Data

Abstract

This research deals with determination of geothermal potential of lower Sokoto Basin, north-western Nigeria using four (4) high resolution aeromagnetic data covering the study area (area bounded by latitude 11.00N to 12.00 N and longitude 4.500E to 5.500E). Depth estimates were made from the spectral analysis of the magnetic anomalies. The polynomial fitting was utilized to suppress the short wavelength components (regional magnetic anomaly of the total magnetic field) in the Sokoto Basin. The residual of the total magnetic field map was then subjected to spectral depth analysis by dividing it into twenty eight (28) overlapping spectral blocks. The log of spectral energies of each blocks were plotted against frequency. The centroid depth (Zo) and depth to top of magnetic boundary (Zt) obtained from the plots were used to estimate the Curie point depth isotherm, which was then used to compute geothermal heat flow of the study area. An estimated depth of 4.69 km to 11.9 was observed for centriod depth(Z0) while the sedimentary
thickness (depth to basement, Zt) ranges from 1.29 km to 2.94 km. The result shows that the Curie point depth Zb ranges between 7.88km and 22.11km with the highest value found at the North-Eastern while lower values are located at the western part with lowest at the central part of the west. For the geothermal heat flow, it varies between 65.84mW/m2 and 184.74 mW/m2, The geothermal heat flow obtained from this study indicates that the study area possess a good source of geothermal potential. Thus, harnessing the geothermal potential in this area would be of added values and advantage to power generation in Nigeria.