Investigating the Geothermal Resource Potential in Parts of North Central Nigeria Using Aeromagnetic Data

Abstract

The assessment of geothermal potential in parts of North Central Nigeria using spectral depth analysis of aeromagnetic data was carried out. The study area is bounded by latitude 9. 00o to 10. 00o N and longitude 7.00o to 9.00 o E with an estimated total area of 24, 200 km2. The Total magnetic intensity map was divided into twenty - eight overlapping blocks, each block was subjected to spectral analyses to obtained centroid depth (Zo) and depth to top of basement (Zt) obtained were used to estimate the curie point depth which was then used to compute geothermal heat flow of the study area. The result of centroid depth varies between 10 km to 2 km, the depth to top of basement ranges from 1.42 km to 0.86 km. The Curie Point Depth (CPD), range from 3.449 km to 19.31 km with an average value of 9.196 km. The maximum CPD is found around the southern part at a depth of 18.5 km and minimum CPD is found around northern part with 14.5 km depth corresponding to areas around Gitata and Naraguta. The corresponding geothermal gradient and heat flow values varying from 30.03 oCkm-1 to 168.16 oCkm-1 with average of 70.98 oCkm-1 and heat flow ranges from 176.24 mWm-2 to 262.77 mWm-2 with an average value of 178.17mWm-2 respectively. The results show that the study area is not viable for geothermal energy due to its high anomalous nature of heat flow.