Abstract
Determining the temperature distribution within the lithosphere requires the knowledge of the radiogenic heat production (RHP) distribution within the crust and the lithospheric mantle. RHP of crustal rocks varies considerably at different scales as a result of the petrogenetic processes responsible for their formation and therefore RHP depends on the considered lithologies. Radioactive heat-production data of granites in north and south-eastern Arabian shield Kingdom of Saudi Arabia are presented. Radiumequivalent uranium (RaeU), thorium (eTh), and potassium (eK) were determined by sealed-can gamma-ray spectrometry on 600 g of coarsely crushed sample. A total of 253 rock samples were investigated, covering all major rock types of the area. Southeastern granite shows higher Heat Production HP (2.19-8.04 mu Wm(-3)) and total Heat Generation Unit (0.76-19.07 HGU) than northeastern granite (HP 1.82-4.12 mu Wm(-3), 4.31-10.35 HGU). North and Southeastern granite locations shows higher average value of total Heat Generation Unit (6.7 HGU and 7.16 HGU) than the average value of 3.8 HGU for the continental crust. The contribution due to U is about 45%, that from Th is 37.7% and 17.3% from K. The corresponding values in north-eastern are 49.1%, 37.8% and 13.1%, respectively. The calculated values showed good agreement with global values except in some areas. These data can be used to discuss the effects of the lateral variation of the RHP rate on the heat flux and the temperature fields in the upper crust. (C) 2018 The Egyptian Society of Radiation Sciences and Applications. Production and hosting by Elsevier B.V.