干旱区生态环境知识资源中心(Arid): The Chemistry of Allanite - Britholite Single Crystal in Alkaline Volcanic Rocks, from Gabal Umm Shaghir Area, Central Eastern Desert, Egypts

Arid

DOI	10.1007/s12633-018-9998-6
	The Chemistry of Allanite - Britholite Single Crystal in Alkaline Volcanic Rocks, from Gabal Umm Shaghir Area, Central Eastern Desert, Egypts
	Shalaby, B. N. A.; Ismail, A. I. M.; Salem, A. K. A.
通讯作者	Ismail, A. I. M.
来源期刊	SILICON
ISSN	1876-990X
EISSN	1876-9918
出版年	2019
卷号	11 期号:4 页码:1809-1816
英文摘要	The present study deals with the mineral chemistry and genesis of two rare earth elements bearing silicate minerals, namely; allanite and britholite, co-existing in a single crystal, encountered in quartz trachyte dyke, considered to be an offshoot from Gabal Umm Shaghir trachytic plug, central Eastern Desert of Egypt. The size of present allanite-britholite crystal is about 0.25 mm in length and 0.10 mm in width. The allanite phase occupies the main bulk of the crystal, while the britholite phase, exits in the form of transversal spine-shaped lamellae. The mineral chemistry and the genesis of the present allanite - britholite phases are discussed based on 10 scanning electron microprobe point analyses. The present study also discuses, through elemental mapping, the distribution and concentration of selected 9 elements; Si, Fe, Mg, Al, Na, Ca, P, La and Ce, and their frequencies between different mineral phases. The average structural formula of present allanite based on 12.5 (O2-) and 8 cations is: (Ca2+)(1.00) (Ce0.343+\, La0.193+, Nd0.143+, Sm0.023+, Y0.113+, Ca0.252+)1.05\ (Mg0.072+, Fe0.692+, Fe0.193+)0.95 (Ti0.024+, Fe0.133+, Al0.853+)1.00 (Al3+)(1.00) (Si4+)(2.99) (O2-)(12.5). The average structural formula of present britholite based on 12.5 (O2-) and 8 cations is: (Ca1.732+, K0.05,+Mg0.102+, Fe0.222+, Ti0.01,4+Al0.14,3+ La0.503+, Ce1.193+, Nd0.443+, Sm0.103+, Y0.50,3+Th0.014+)5.00 (Al0.123+, P0.395+, Si2.494+)3.00 (O-2)(12.5). The present study concluded that, the coexistence of britholite - allanite mineral phases were resulted from rare earth elements (REEs) + P enriched hydrothermal solutions, undergone percolation and attacking the allanite crystal along cleavage planes. The reaction processes involved, essentially, substitution of P2O5 and REEs2O3 for Al2O3 and SiO2.
英文关键词	Allanite Britholite Rare earth elements Alkaline rocks Trachyte
类型	Article
语种	英语
国家	Egypt
收录类别	SCI-E
WOS记录号	WOS:000486225200012
WOS关键词	NOMENCLATURE ; MINERALS
WOS类目	Chemistry, Physical ; Materials Science, Multidisciplinary
WOS研究方向	Chemistry ; Materials Science
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/218850
作者单位	Natl Res Ctr, Geol Sci Dept, PO 12622,33 El Bohooth St, Giza, Egypt
推荐引用方式 GB/T 7714	Shalaby, B. N. A.,Ismail, A. I. M.,Salem, A. K. A.. The Chemistry of Allanite - Britholite Single Crystal in Alkaline Volcanic Rocks, from Gabal Umm Shaghir Area, Central Eastern Desert, Egypts[J],2019,11(4):1809-1816.
APA	Shalaby, B. N. A.,Ismail, A. I. M.,&Salem, A. K. A..(2019).The Chemistry of Allanite - Britholite Single Crystal in Alkaline Volcanic Rocks, from Gabal Umm Shaghir Area, Central Eastern Desert, Egypts.SILICON,11(4),1809-1816.
MLA	Shalaby, B. N. A.,et al."The Chemistry of Allanite - Britholite Single Crystal in Alkaline Volcanic Rocks, from Gabal Umm Shaghir Area, Central Eastern Desert, Egypts".SILICON 11.4(2019):1809-1816.