干旱区生态环境知识资源中心(Arid): Radioactivity and mineralogy of the altered granites of the Wadi Ghadir shear zone, South Eastern Desert, Egypt

Arid

DOI	10.1007/s11631-012-0546-6
	Radioactivity and mineralogy of the altered granites of the Wadi Ghadir shear zone, South Eastern Desert, Egypt
	Raslan, Mohamed F.; El-Feky, Mohamed G.
通讯作者	Raslan, MF
来源期刊	ACTA GEOCHIMICA
ISSN	2096-0956
EISSN	2365-7499
出版年	2012
卷号	31 期号:1 页码:30-40
英文摘要	Quartz-diorite, gneissose granodiorites, two-mica granite and perthite leucogranie are the main rock units cropping out in the Wadi Ghadir area, South Eastern Desert of Egypt. Along the NNE-SSW mega-faults, a broad brittle shear zone is developed in the Ghadir two-mica granite. Brittle deformation is manifested by severe mylonitization and alteration of these granites. These sheared altered granites are characterized by the presence of radioactive mineralization, associated with alteration features such as silicification, hematization and kaolinitization. Radioelement measurements revealed that the unaltered and altered two-mica granites are considered as uraniferous granites. The average uranium and thorium contents in the unaltered two-mica granites are 12.29x10(-6) and 19.81x10(-6), respectively, and the average Th/U ratio is 1.62. The altered granites exhibit higher concentrations of U (averaging 97.949), but have lower Th and Th/U ratios (13.83 and 0.16, respectively), which indicates uranium enrichment in the granites. Binary relations of eTh/eU against either eU or eTh and eU with eTh in the studied granites suggest that the distribution of radioactive elements not only magmatic (positive correlation between eU and eTh), but also due to hydrothermal redistribution of radioelements (weak correlation between eU and eTh/eU). The magmatic U and Th are indicated by the presence of uraninite, thorite, zircon and monazite whereas the evidence of hydrothermal mineralization is the alteration of rock-forming minerals such as feldspar and the formation of secondary minerals such as uranophane and pyrite. Microscopic, XRD and scanning electron microscopic studies revealed the presence of uraninite, uranophane, thorite, Ce-monazite and zircon, in addition to phlogopite-fluor mica in the studied altered granites of the Wadi Ghadir shear zone.
英文关键词	granite radioelement measurement uraninite uranophane thorite Ce-monazite zircon Wadi Ghadir
类型	Article
语种	英语
收录类别	ESCI
WOS记录号	WOS:000218336200004
WOS类目	Geochemistry & Geophysics
WOS研究方向	Geochemistry & Geophysics
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/330046
作者单位	[Raslan, Mohamed F.; El-Feky, Mohamed G.] Nucl Mat Author, El Maadi POB 530, Cairo, Egypt
推荐引用方式 GB/T 7714	Raslan, Mohamed F.,El-Feky, Mohamed G.. Radioactivity and mineralogy of the altered granites of the Wadi Ghadir shear zone, South Eastern Desert, Egypt[J],2012,31(1):30-40.
APA	Raslan, Mohamed F.,&El-Feky, Mohamed G..(2012).Radioactivity and mineralogy of the altered granites of the Wadi Ghadir shear zone, South Eastern Desert, Egypt.ACTA GEOCHIMICA,31(1),30-40.
MLA	Raslan, Mohamed F.,et al."Radioactivity and mineralogy of the altered granites of the Wadi Ghadir shear zone, South Eastern Desert, Egypt".ACTA GEOCHIMICA 31.1(2012):30-40.