干旱区生态环境知识资源中心(Arid): Magmatic and hydrothermal evolution of highly-fractionated rare-metal granites at Gabal Nuweibi, Eastern Desert, Egypt

Arid

DOI	10.1016/j.lithos.2021.106405
	Magmatic and hydrothermal evolution of highly-fractionated rare-metal granites at Gabal Nuweibi, Eastern Desert, Egypt
	Moussa, Hilmy E.; Asimow, Paul D.; Azer, Mokhles K.; Maaty, Moustafa A. Abou El; Akarish, Adel I. M.; Yanni, Nagy N.; Mubarak, Heba S.; Wilner, M. J.; Elsagheer, Mustafa A.
通讯作者	Moussa, HE (corresponding author), Natl Res Ctr, Geol Sci Dept, Cairo 12622, Egypt.
来源期刊	LITHOS
ISSN	0024-4937
EISSN	1872-6143
出版年	2021
卷号	400
英文摘要	The Nuweibi intrusion was emplaced during the final tectono-magmatic stage of Arabian-Nubian Shield development (ANS). Two cogenetic phases of intrusion can be recognized in the field: the early phase is represented by porphyritic albite granite and the final phase by non-porphyritic albite granite. Mineralogically, both phases are essentially composed of albite, quartz, and K-feldspars with subordinate muscovite. Accessory minerals include fluorite, zircon, NbTa oxides, cassiterite, beryl, topaz, and garnet. Geochemically, the Nuweibi intrusion consists of extensively fractionated rare-metal granite with low contents of TiO2, FeOt, CaO, MgO, P2O5, Sr, and Ba in contrast to elevated concentrations of alkalis, Rb, Nb, Ta, and Hf. Their peraluminous (molar Al2O3/[CaO + Na2O + K2O] = 1.06-1.15) and low-P (P2O5 < 0.008 wt%) character identify them as highly fractionated Itype granites. The primary magma of the Nuweibi intrusion was most likely generated by partial melting of the juvenile crust of the ANS. We document numerous lines of evidence that the Nuweibi albite granite was formed by extensive fractional crystallization followed by interaction with magmatically-derived, F-rich hydrothermal solutions. The REE patterns of the Nuweibi albite granite show marked negative Eu anomalies (Eu/Eu* = 0.01-0.15) as well as prominent M-type tetrad effects (TE1,3 = 1.332-3.536), typically seen in highly differentiated granites and attributed to exchange with hydrothermal fluid. Anomalous ratios of isovalent twin elements such as Nb/Ta, Zr/Hf, and Y/Ho likewise indicate exchange with hydrothermal fluid. The primary raremetal accessory minerals are restricted to the Mn-rich part of the columbite-tantalite series; this manganoan trend is characteristic of highly fractionated granites. Likewise, the presence of wodginite, a Sn-bearing mineral, is a unique fingerprint of highly evolved rare-metal granites. Late-stage hydrothermal overprint of the primary rare-metal mineralization is preserved by rims of fluorcalciomicrolite partly replacing columbite-(Mn) and tantalite-(Mn). Accumulation of residual volatile-rich melt and exsolved fluids in the upper part of the magma chamber produced stockscheider pegmatite, greisen, and quartz veins that cut the peripheries of the Nuweibi intrusion and the surrounding country rocks.
英文关键词	Arabian-Nubian Shield Nuweibi intrusion Rare-metal granite Nb-Ta oxides tetrad effect
类型	Article
语种	英语
开放获取类型	Green Accepted
收录类别	SCI-E
WOS记录号	WOS:000697504500001
WOS关键词	A-TYPE GRANITES ; OXIDE MINERALS ; U-PB ; TA MINERALIZATION ; BAERZHE GRANITES ; TRACE-ELEMENTS ; NB ; PEGMATITE ; BEARING ; GEOCHEMISTRY
WOS类目	Geochemistry & Geophysics ; Mineralogy
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/364128
作者单位	[Moussa, Hilmy E.; Azer, Mokhles K.; Maaty, Moustafa A. Abou El; Akarish, Adel I. M.; Yanni, Nagy N.; Mubarak, Heba S.; Elsagheer, Mustafa A.] Natl Res Ctr, Geol Sci Dept, Cairo 12622, Egypt; [Asimow, Paul D.; Wilner, M. J.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA
推荐引用方式 GB/T 7714	Moussa, Hilmy E.,Asimow, Paul D.,Azer, Mokhles K.,et al. Magmatic and hydrothermal evolution of highly-fractionated rare-metal granites at Gabal Nuweibi, Eastern Desert, Egypt[J],2021,400.
APA	Moussa, Hilmy E..,Asimow, Paul D..,Azer, Mokhles K..,Maaty, Moustafa A. Abou El.,Akarish, Adel I. M..,...&Elsagheer, Mustafa A..(2021).Magmatic and hydrothermal evolution of highly-fractionated rare-metal granites at Gabal Nuweibi, Eastern Desert, Egypt.LITHOS,400.
MLA	Moussa, Hilmy E.,et al."Magmatic and hydrothermal evolution of highly-fractionated rare-metal granites at Gabal Nuweibi, Eastern Desert, Egypt".LITHOS 400(2021).