Distribution of Uranium, Thorium, and Potassium and Their Bearing on the Radiogenic Heat Production of Some Granitic Rocks from the Eastern and Western Deserts

Abstract

The geochemical composition and radiogenic heat production (RHP) of granitoids from fourteen plutons in Egypt’s Eastern and Western Deserts was studied using inductively coupled plasma mass spectrometry (ICP-MS). The results show that light rare earth elements (LREEs) dominate over heavy rare earth elements (HREEs), and the Th/U ratios range from 1.75 to 6.81. RHP values vary significantly, from 1.31 to 9.17 µW/m³, with El Dib pegmatitic syenite showing the highest value and Abu Dabbab, the lowest. El Dib and Qattar granites are classified as high heat-producing rocks (HHP), while El Dokhan, El Sibai, Missikat, and Bir Safsaf granites fall into the moderate category (MHP). The remaining plutons are considered as low heat-producing (LHP), though their average RHP still exceeds the global upper continental crust average. No clear relationship was found between RHP and Th/U ratios or SiO₂ content. γ-Ray spectrometry (GRS) proved to be a reliable complementary method for assessing RHP. Overall, the findings highlight the geothermal potential of these granitic intrusions as promising heat sources in Egypt’s desert regions.