Natural radioactivity and mineral chemistry aspects of rare metal mineralisation associated with mylonite at Wadi Sikait, South Eastern Desert, Egypt
Ahmed E. Abdel Gawad, M.A. Ali, Mohamed M. Ghoneim, Atef El‐Taher
Abstract
The natural radiometric data revealed that eU and eTh-contents of mylonite rocks reach up to 464 and 1283 ppm, respectively. The studied mineralised mylonites are enriched in thorite, ishikawite and zircon as well as other accessories (ferrocolumbite, xenotime, fergusonite, synchysite, cassetrite, apatite, fluorite, galena and barite). Ishikawaite is considered as the almost enriched mineral in uranium contents, whereas UO2 ranges from 31.02 to 50.78 wt%. The higher concentrations of UO2 reached up to 15.88 wt% and ThO2 up to 4.32 wt% related to metamictization of columbite. Some zircon crystals possess higher values of HfO2 reached up to 6.38 wt% could be affected by hydrothermal activity. Both xenotime and fergusonite are enriched in HREE (average ∑HRE2O3 31.19 and 14.1 wt%, respectively) whereas synchysite is main LREE bearing mineral (average ∑LRE2O3 55.78 wt%).