ASSESSMENT OF GEOTHERMAL POTENTIAL IN PARTS OF BORNO BASIN NORTH-EAST NIGERIA USING AEROMAGNETIC AND AERORADIOMETRIC DATA

Abstract

This research was aimed towards the assessment of geothermal potential part of Borno Basin north-east Nigeria using aeromagnetic and aeroradiometric data. Regional/Residual separation was performed on the total magnetic intensity map using polynomial fitting, and the residual map was divided into nine spectral blocks of which the log of spectral energies were plotted against frequency. Centroid depth and depth to top boundary obtained was used to estimate the Curie point depths, which were further used in computing the geothermal heat flow of the study area reveals that the curie point depth ranges from 9.74 km to 21.68 km with an average value of 15.71 km. The geothermal gradient, vary between 26.75 oC/km and 59.55 oC/km. The results shows that the heat flow values of the study area vary between

71.09 mW/m2 and 150.07 mW/m2, low values of 65 mW/m2 to 90 mW/m2 are located at the Northeastern and Northwestern part of area (Awiam and Bajoga) and higher value of 100 mW/m2 to 150 mW/m2 can be located at most part of the southcentral part (Dukku and Bajoga). This shows that the geothermal heat flow varies between 67.41 mWm-2 and 150.07 mWm-2. The aeroradiometric data covering the study area was also analysed to estimate the radiogenic heat contribution. The radioactive heat production values vary between 1.25 µW/m2 and 2.03 µW/m2 with an average of 1.43 µW/m2. The estimated heat flow value of 80 mW/m2 to 100 mW/m2 obtained around Awiam, Dukku (north/western), and Nafada and Bajoga (Northeastern and southeastern) region of the study area makes the area to be of favourable for geothermal exploration.