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DOI	10.1016/j.gexplo.2024.107475
	Chemical and boron isotopic compositions of tourmaline from the pegmatite in Ke'eryin rare metal orefield, Eastern Tibet: Implications for pegmatitic evolution
	Yu, Deshui; Yan, Haibo; Wang, Shoujing; Xu, Deru; Wang, Zhilin; Ma, Chi; Wei, Fushuai
发表日期	2024
ISSN	0375-6742
EISSN	1879-1689
起始页码	262
卷号	262
英文摘要	Pegmatites occur widely in the Ke'eryin rare metal orefield. The genesis and evolution of the Ke'eryin pegmatites are still in dispute, and morphological and geochemical studies on tourmalines from the Ke'eryin pegmatites are limited. In this study, in-situ analyses of major and trace elements and B isotope were conducted to uncover the origin of tourmaline and the evolution of related pegmatites. Three types of tourmaline from the Ke'eryin barren pegmatite were identified: elongated columnar or needle-columnar tourmaline (Tur-1 type), isolated, disseminated, irregular, and massive tourmaline (Tur-2 type), and long columnar tourmaline (Tur-3 type). Petrographically, the Tur-1 type crystallized at the early stage of pegmatitic crystallization sequence, the Tur-2 type possibly formed at the early- and/or syn-pegmatitic crystallization sequence, whereas the Tur-3 type likely formed at the relatively late crystallization sequence. Compositionally, most tourmalines belong to the alkali group with a few falling in the vacancy group. All the tourmalines show a schorl composition and are of magmatic origin. Chemical variations from the Tur-1 to Tur-3 tourmalines are controlled by magma fractionation and melt compositions rather than crystal chemical effects. Most tourmalines follow the (Na, Mg)(Xvac, Al)_1, (Mg, OH)(Al, O)_ 1, and (Ca, Mg2)(Xvac, Al2)_ 1 exchange vectors. The higher contents of Zn, Sn, Li, Be, Nb, and Ta and negative Eu anomalies in the Tur-3 type indicate that it was likely crystallized at a more evolved stage. In combination with textural evidence and tourmaline chemistry, we suggest that the Tur-1 and Tur-2 types were formed at the relatively earlier stage of pegmatite-forming magma and the Tur-3 type was likely formed closer to the end-stage of barren pegmatite crystallization. The B isotopic compositions are relatively homogeneous and display slightly higher in the Tur-3 type, which were likely caused by fractional crystallization during B-rich magma evolution. It can be inferred that the tourmaline in more evolved and/or Li-mineralized pegmatite with magma evolution should have higher Li, Be, Nb, Ta, and Sn contents, implying that tourmaline chemistry may be used as a potential exploration indicator for rare metal mineralization.
英文关键词	Pegmatite; Tourmaline; Boron isotope; Mineral chemistry; Ke'eryin
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:001235506900001
来源期刊	JOURNAL OF GEOCHEMICAL EXPLORATION
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/306192
作者单位	China Geological Survey; Zhengzhou Institute of Multipurpose Utilization of Mineral Resources, Chinese Academy of Geological Sciences; Ministry of Natural Resources of the People's Republic of China; Chinese Academy of Sciences; Guangzhou Institute of Geochemistry, CAS; Fuzhou University; East China University of Technology; Central South University
推荐引用方式 GB/T 7714	Yu, Deshui,Yan, Haibo,Wang, Shoujing,et al. Chemical and boron isotopic compositions of tourmaline from the pegmatite in Ke'eryin rare metal orefield, Eastern Tibet: Implications for pegmatitic evolution[J],2024,262.
APA	Yu, Deshui.,Yan, Haibo.,Wang, Shoujing.,Xu, Deru.,Wang, Zhilin.,...&Wei, Fushuai.(2024).Chemical and boron isotopic compositions of tourmaline from the pegmatite in Ke'eryin rare metal orefield, Eastern Tibet: Implications for pegmatitic evolution.JOURNAL OF GEOCHEMICAL EXPLORATION,262.
MLA	Yu, Deshui,et al."Chemical and boron isotopic compositions of tourmaline from the pegmatite in Ke'eryin rare metal orefield, Eastern Tibet: Implications for pegmatitic evolution".JOURNAL OF GEOCHEMICAL EXPLORATION 262(2024).