气候变化领域集成服务门户(CCPortal): B-rich melt immiscibility in Late Cretaceous Nattaung granite, Myanmar: Implication by composition and B isotope in tourmaline

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DOI	10.1016/j.lithos.2020.105380
	B-rich melt immiscibility in Late Cretaceous Nattaung granite, Myanmar: Implication by composition and B isotope in tourmaline
	Li, Jin-Xiang; Fan, Wei-Ming; Zhang, Li-Yun; Ding, Lin; Yue, Ya-Hui; Xie, Jing; Cai, Fu-Long; Sein, Kyaing
通讯作者	Li, JX (通讯作者)
发表日期	2020
ISSN	0024-4937
EISSN	1872-6143
卷号	356
英文摘要	There is a strong controversy about the petrogenesis of tourmaline nodules and their relationship with coeval tourmaline-bearing granites, which are commonly associated with magmatic-hydrothermal rare metal deposits (e.g., Sn, Nb, and Ta). In this study, tourmaline is extensively distributed in tourmaline-bearing nodules (NT-type), pegmatite (PT-type), and fine-grained granitic dyke (GT-type), which are hosted by the Late Cretaceous Nattaung biotite granite (Myanmar). Zircon U-Pb dating results (similar to 71 Ma) indicate that PT- and GT-types tourmaline-bearing magmatic rocks formed synchronously with biotite granite. All tourmalines have alkali group and schorl composition with Mg/(Mg + Fe) ratios of 0.03-0.45 and Na/(Na + Ca) ratios of 0.73 to 1.00. NT-type tourmaline shows high Nb/Ta ratios and V and Sr contents, indicating that they were likely crystallized from B-rich melts early immiscible with less evolved granitic magmas. yr- and GT-type tourmalines probably formed in aggregated B-rich melts that continuously separated from more evolved granitic magma, supported by their low Nb/Ta ratios and V and Sr contents. In addition, the studied tourmaline displays a slight variation of B isotopic compositions (delta B-11 values ranging from -12.2 +/- 0.7 parts per thousand to -14.9 +/- 0.4 parts per thousand), likely resulted by Rayleigh fractionation of tourmaline. Their light B isotopic values are consistent with those of average continental crust, also revealing that the Nattaung granite was mainly derived from partial melting of the ancient Sibumasu crust. Importantly, late-stage PT- and GT-type tourmalines have higher Sn, Zn, Nb, and Ta contents than early-stage NT-type tourmaline, suggesting that the evolved B-rich magma could be one precursor to produce Sn-Nb-Ta-Zn deposits associated with extensive tourmaline in the world. (C) 2020 Elsevier B.V. All rights reserved.
关键词	A-TYPE GRANITES ZIRCON U-PB BORON-ISOTOPE TECTONIC EVOLUTION WESTERN MYANMAR PEGMATITE SYSTEM SOUTHERN MYANMAR FLUID HF CONSTRAINTS
英文关键词	Tourmaline; Granite; B isotope; Melt immiscibility; Myanmar
语种	英语
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS类目	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:000520941500016
来源期刊	LITHOS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/259808
推荐引用方式 GB/T 7714	Li, Jin-Xiang,Fan, Wei-Ming,Zhang, Li-Yun,et al. B-rich melt immiscibility in Late Cretaceous Nattaung granite, Myanmar: Implication by composition and B isotope in tourmaline[J]. 中国科学院青藏高原研究所,2020,356.
APA	Li, Jin-Xiang.,Fan, Wei-Ming.,Zhang, Li-Yun.,Ding, Lin.,Yue, Ya-Hui.,...&Sein, Kyaing.(2020).B-rich melt immiscibility in Late Cretaceous Nattaung granite, Myanmar: Implication by composition and B isotope in tourmaline.LITHOS,356.
MLA	Li, Jin-Xiang,et al."B-rich melt immiscibility in Late Cretaceous Nattaung granite, Myanmar: Implication by composition and B isotope in tourmaline".LITHOS 356(2020).