Pattern of Radiogenic Heat Production in Rock Samples of Southwestern Nigeria

摘要

Survey for radiometric minerals has become important over the last few decades because of the demand for alternative to present common source of energy. Radiometric survey is one of the geophysical techniques in use in exploration for geothermal energy, which is generated mainly from the decay of long-lived radioactive isotopes. The main objective of this study is to obtain the pattern of contribution of the elements to the radiogenic heat production (RHP) in the Southwestern Nigeria. Fresh rock samples were collected from six states in Southwestern Nigeria and the concentration of 48K, 238U and 232Th from the samples were determined in the laboratory through spectrometry of emitted gamma rays, using a cylindrical NaI(Tl) detector. The results show that the contribution and rate of heat production of 40K, 238U and 232Th in the samples vary significantly with geological locations, with 40K as the major element which predominates in heat production, while 238U and 232Th are trace elements. Theradiogenic heat production elements (RHPE) contribution shows that Ekiti, Ondo and Osun have the same pattern of radiogenic heat production contribution of the elements to the radiogenic heat production (RHP) in the Southwestern Nigeria. Fresh rock samples were collected from six states in Southwestern Nigeria and the concentration of 48K, 238U and 232Th from the samples were determined in the laboratory through spectrometry of emitted gamma rays, using a cylindrical NaI(Tl) detector. The results show that the contribution and rate of heat production of 40K, 238U and 232Th in the samples vary significantly with geological locations, with40K as the major element which predominates in heat production, while 238U and 232Th are trace elements. The radiogenic heat production elements (RHPE) contribution shows that Ekiti, Ondo and Osun have the same pattern of radiogenic heat production.