Mineralogy, Geochemistry and Radioactivity of Stream Sediments of Wadi Abu Harba-North Eastern Desert, Egypt

Abstract

Wadi Abu Harba is located in North Eastern desert. This wadi is surrounded by syenogrenites and alkali feldspar granite with some dyke swarms of acidic and basic composition. The heavy minerals represented by 1.098 % magnetite, 0.3136 % ilmenite, 0.1208 % leucoxene, 0.3732 % rutile, 0.2516 % zircon, 0.01684 % monazite, 0.118 % garnet and 0.1596 % titanite. Radiometric analysis revealed that the average equivalent uranium content (eU) is 1.64 ppm and the average equivalent thorium is (eTh) is 9.64 ppm. On the other hand, the analysis and identification of several separated mineral grains of some stream sediments samples using a scanning electron microscope and X-ray diffraction revealed the presence of several economic minerals. These minerals include zircon, uranothorite,
thorianite, monazite, cerite, apatite, fluorite, garnet and hematite. The present study proved that zircon, uranothorite, thorianite and monazite are the main radioactive minerals responsible for the radioactivity of the studied stream sediments and may control the geochemical enrichment of elements such as Th, U, Zr, Y, and Nb.