Gehan A M Aly
Nuclear Materials Authority, Egypt
Title: Geochemistry of some rare metals mineralization in gibbsite sediments at Abu El Mogherat Area, Southwestern Sinai, Egypt
Biography
Biography: Gehan A M Aly
Abstract
Gibbsite sediments occur in Abu El Mogherat area, located about 40 km to the east of Abu Zenima town, Southwestern Sinai, Egypt. These sediments occur as a blanket or karst on the surface of the Lower Carboniferous Um Bogma Formation. Kaolinite, goethite, hematite, alunite, quartz, REE minerals (Bastansite and Cerianite) and accessories bearing REEs and radioactivity (xenotime and zircon), celestite, barite, chalcophanite, lithiophorite and coronadite beside concentrations of some base metals as Cu, Zn, Pb and Ni are associated with gibbsite. The studied gibbsite is relatively enriched in Al2O3, Fe2O3, MnO, Co, Ni, Cu, Zn, Pb, Cd, As, Bi, W and U. The REE content (341 to 5111 ppm) shows a relative enrichment in LREE than HREE. The chemically analyzed U (Uc) and its radiometric equivalent (eU) in Abu El Mogherat gibbsite are estimated to be 345 and 281 ppm, respectively. This suggests a disequilibrium state. The high content of U and its disequilibrium state besides the almost complete absence of Th, suggest secondary supergene enrichment of U.