Radionuclides Differentiation during the Secondary Processes of Pb-Zn Mineralization, Gabal El Rousas, Eastern Desert, Egypt

Abstract

The primary mineralization of Pb-Zn in Gabal El Rousas on the Egyptian Red Sea hills was subjected to secondary processes led to the redistribution of those mineralization and became much abundant than the hypogene minerals. This study is restricted on the differentiation in the associated radionuclides during these secondary processes. Seven samples from the mineralized ore and six samples from the hosting Miocene sedimentary rocks were collected and studied radiometrically using the Hyper Pure Germanium (HPGe) detector. The results showed that the 238U and 226Ra are concentrated in the hosting rocks, while 40K on the other hand is concentrated in the mineralized zones. 232Th did not change much due to its immobility, while in the mineralized group, 214Pb and 214Bi are nearly half the activity concentration of their parent 226Ra which is due to the escape of some 222Rn during the secondary processes that affected the primary mineralization. With respect to the environmental impact, the absorbed dose rate, annual effective dose rate, radium equivalent, radioactivity level index and external radiation hazard index for the mineralized samples are three times lower than the hosting sedimentary rocks.