Geophysical investigation of geothermal energy resource potential for electricity generation: A case study of Ikogosi –Ado Ekiti and Ijebu Ife, South Western Nigeria

This research endeavors to access the spectral depth, basement structure variability, and deduce heat and geothermal distribution of the study areas Ijebu-Ife and Ikogosi. Aeromagnetic and geological methods were applied in the analysis using Oasis Montaj Surfer 8 and Mat Lab using sheets 244 and 281. Geological analysis revealed that Ikogosi was found to be underlain by three rock units; quartz schist, quartz mica schist, and quartzite, while Ijebu-Ife is underlain by Quartzite, quartzite Schist, and migmatite. The Ijebu-Ife Curie point depth values ranges from (13.10- 22.30) km, the geothermal gradient values ranges from (25.01– 37.123) °C/km and the heat flow values ranges from (68.736- 108.079) mW/m2. The SE edge,Abigi, Agbure, and Ilushin hosts the highest values of heat flow and geothermal gradient with corresponding shallowest values of curie point depth (Fig. 4.2 a-c). Regions like Omo, Oso, Kojala, Oniparaja also good geothermal manifestations. Generally, for a viable geothermal reservoir, a heat flow range of (80 - 100) mW/m2is recommended, hence it can be inferred that every region on the study area could be considered as having good prospect except within the Northern region, Gbamu of the study area with low heat flow below 80 mWm-2. The Ikogosi Curie point depth values ranges from (6.89- 16.15) km, the geothermal gradient values ranges from (39.2– 84.74) °C/km and the heat flow values ranges from (96.05- 207.31) mW/m2 (Figs. 4-1 a-c). The NW edge covering Ofale, Iye, Ifere, Iddo-Ekiti, Ijero-Ekiti, Aramoko, and Ikogosi hosts the highest anomalous values of heat flow and geothermal gradient with corresponding shallowest values of Curie point depth (Fig. 4.2 a-c). Generally, for a viable geothermal reservoir, a heat flow range of 80 to 100 mW/m2is recommended, hence it can be inferred that every region on the study area could be considered as having good prospect of the study area with high heat flow above 80 – 100 mWm-2.