Radiogenic heat production as an indicator for geothermal energy exploration in Kurdistan Region, Iraq

Abstract

The apportionment of naturally occurring radionuclides ( 238 U, 232 Th, and 40 K) within granite samples supplies essential data related to heat generation and thermal properties of the crust. Radiogenic heat production (RHP) was estimated in this work for granite rocks gathered from the Raparin region within Kurdistan, Iraq. A total of 45 granite samples were examined through HPGe gamma-ray spectrometry to evaluate the concentration levels of 238 U, 232 Th, and 40 K. The radionuclide concentrations displayed substantial discrepancy across the investigated rock samples, indicating variation in fundamental enrichment and geological development within the granitoid bodies. The average value of RHP is 2.55 µW m − 3 and the range varied from 1.72 to 3.76 µW m − 3 . The obtained RHP values recommended moderate radiogenic heat contribution. The contribution of three nuclides to total heat production is sequenced as 238 U> 232 Th> 40 K. The heterogeneous distribution patterns of the radionuclides and RHP were revealed through spatial analysis. Thus, the differentiation in magmatic and irregularity in regional geology could impact the thermal properties of the Zagros structure. Finally, this study provides advanced baseline radiogenic information for granite rocks for the Zagros Fold-Thrust Belt and contributes a new database for limited geothermal for the Kurdistan region of Iraq.