MINERALOGY AND GEOCHEMISTRY OF A NEW URANIUM OCCURRENCE AT THE DECANT OF WADI EL REDDAH, NORTHEASTERN DESERT, EGYPT | ||||
| Nuclear Sciences Scientific Journal | ||||
| Volume 9, Issue 1, April 2020, Page 55-78 PDF (15.37 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/nssj.2020.265500 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
| HOSSAM A. KHAMIS; OSAMA A. EBYAN; NEVEEN S. ABED | ||||
| Nuclear Materials Authority , Cairo, Egypt | ||||
| Abstract | ||||
| Gattar granites are affected by widespread deuteric and post magmatic hydrothermal activities. Hydrothermal alterations associated U-mineralization in the host granites include hematitization, sericitization, episyenitization (desilicification) and fluoritization. Alkali metasomatism is represented by microclinization, sericitization and muscovitization of alkali feldspar and plagioclase. Two new radioactive occurrences were discovered namely GXXIII and GXXIV. The first radioactive occurrences is located 150-180 m from the contact between the Gattarian granite and the Hammamat molasse sediments. The intersection show highly hematitized hallows with deep brown to reddish pink color associating some remarkable silicification. The other radioactive location is controlled by several factors mainly represented by the NE-SW basic dyke of 2-3 m thickness and bound the radioactive spots from the north. This radioactive location is located some 350 m from the GXXIV location and is more than 0.5 Km away from the granite- Hammamat contact zone. The location includes three radioactive spots arranged along major shear zone trending N25E-S25W. Generally, loss and gain calculations indicate that the altered samples exhibit an increase in total iron, K, Mn, Al, Ca and Mg and decrease in Na, P, Si, L.O.I. and Ti, in addition to elevated contents of Cu, Co, Pb, Cs, Y, Ga, Hf, Sn, V, Nb, Rb, Ta, Th, U, Tl, Zr, W, Zn and depleted in Ba, Sr and Ni. Y/Ho ratios value show complexation with fluorine and carbonates which is confirmed by the presence of fluorite and calcite. Hydrothermal alteration during late magmatic stage is identified by the unusual Zr/Hf, Sr/Eu, Nb/Ta, La/ Nb, La/ Ta, Rb/Sr and U/Th ratios. Highly evolved nature of these rocks is also manifested by irregular REE's pattern that is most visible in late magmatic differentiates with strong hydrothermal or deuteric alteration represented with K-metasomatism and fluoritization. Positive correlation of uranium and most of trace and rare earth elements indicate co-mobilization and precipitation of these elements. Microscopic and scanning electron microscopic studies revealed the presence of uranophane, kasolite, cotunite, coronadite, galena, fluorite and amazonite. | ||||
|
Statistics Article View: 47 PDF Download: 78 |
||||
