Geology, Petrology and Radioactivity of Gabal Ghurab ar-Rayyan-Gabal Ghurab Al-Atshan Area, South Eastern Desert, Egypt

Gabal Ghurab Ar-Rayyan - Gabal Ghurab Al-Atshan area is represented by older and younger granites that intruded in metasedimentary country rocks Both of them are cut by mafic dykes and pegmatites and capped by Nubian sandstones. The area is dissected by pthorium without conspicuous leaching and/or addition The present study showed that the positive anomalies follow pegmatite bodies, albitized zones and hematitized spots. Both equivalent U and Th contents in albitized zones of syenogranites of G. Ghurab Arthe main reason for albitization and consequently U-Th addition rather thanthe meteoric water (supergene), which only adds uranium The minerals separation of albitized zones of the syenogranites revealed the presence of allanite, xenotime, zircon and samarskite which may cause their high radioactivity level The high radioactive