Ground Radiometric Survey and Geothermal Energy Investigation In Ikogosi Warm Spring, Ekiti, Southwestern Nigeria

Abstract

Gamma-Ray Spectrometer was used to measure radiations from natural radionuclides in Ikogosi warm spring in order to determine the pattern of natural radioactivity, elemental concentration and radiogenic heat production emanating from surface rock units. The pattern of Radiogenic heat production rates of surface rock units at Ikogosi warm spring was determined through quantitative determination of concentrations of Uranium, Thorium and Potassium isotopes in the rock units. The radiogenic heat production rates ranged from Below Detectable Limit (BDL) to 0.0098 pW/kg for 40K, BDL to 622.08 pW/kg for 232Th and BDL to 723.52 pW/kg for 238U. The Total heat generated or production from the radionuclide (THP) varied from 65.59 pW/kg to 1154.65 pW/kg and a mean value of 454.59 pW/kg for the study area. The measurement of radioactive contents (2.46 ppm U, 8.61 ppm Th and 1.18 % K) of surface rocks obtained for the area appears to be comparatively high enough to be a geothermal resource potential in comparison with other know geothermal sites in the world. The average total heat production in the study area is a manifestation of the geological rock types. Uranium has the highest heat production; followed by 232Th and 40K has the lowest. The ratio of 238U contribution to radiogenic heat production with respect to 232Th and 40K is 1.0:0.57:0.000018.