气候变化领域集成服务门户(CCPortal): Highly fractionated Late Eocene (similar to 35 Ma) leucogranite in the Xiaru Dome, Tethyan Himalaya, South Tibet

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DOI	10.1016/j.lithos.2015.11.026
	Highly fractionated Late Eocene (similar to 35 Ma) leucogranite in the Xiaru Dome, Tethyan Himalaya, South Tibet
	Liu, Zhi-Chao; Wu, Fu-Yuan; Ding, Lin; Liu, Xiao-Chi; Wang, Jian-Gang; Ji, Wei-Qiang
通讯作者	Liu, ZC (通讯作者)
发表日期	2016
ISSN	0024-4937
EISSN	1872-6143
起始页码	337
结束页码	354
卷号	240
英文摘要	The Xiaru dome is located in the middle section of the North Himalayan Gneiss Domes belt in southern Tibet The leucogranite, which crops out in the core of the Xiaru dome, is a typical medium-grained garnet + tourmaline + muscovite leucogranite. U-(Th)-Pb dating of zircon and monazite from the leucogranite yielded ages of approximately 35 Ma. This finding supports a growing body of evidence indicating that an extensive magmatic event occurred during the late Eocene in the Himalayas. This leucogranite is strongly peraluminous with A/CNK values of 1.08-1.52 and characterized by evolved geochemical composition with high contents of SiO2 and alkali elements; low levels of CaO, MgO, TiO2, and FeOT; enriched large-ion lithophile elements (such as Rb); and depleted of high-field-strength elements (such as Nb, Zr, and Hf). The non-CHARAC (CHarge-And-Radius-Controlled) trace element behaviors, which are typical of a highly fractionated granite system, were recorded in the whole rock and the accessory minerals of the Xiaru leucogranite. Furthermore, the magmatic zircon overgrowths have extremely high content of Hf, consistent with those from the highly fractionated aqueous-like fluid system. In addition, whole-rock geochemical fractionation trends were observed, which can be explained by crystal fractionation of biotite, K-feldspar, zircon, xenotime, and monazite. These geochemical features indicate that the Xiaru leucogranite is a typical highly fractionated granite. The geochronological and geochemical features of the inherited zircons from the Xiaru leucogranite show a close affinity to those of the country rocks, suggesting a certain degree of assimilation from the country rocics during melt ascent and emplacement. Although a restricted range of epsilon(Hf)(t) values from -12.8 to -6.6 with Hf T-DM2 model ages of 1.2-1.6 Ga was obtained from the late Eocene zircons, it is invalid to constrain the source of the parental magma due to the strong fractionation and assimilation processes. (C) 2015 Elsevier B.V. All rights reserved.
关键词	MALASHAN GNEISS DOME A-TYPE GRANITES U-PB TECTONIC EVOLUTION CRUSTAL ANATEXIS TRACE-ELEMENTS GEOCHEMICAL CONSTRAINTS EXTREME FRACTIONATION PERALUMINOUS GRANITE NORTH HIMALAYA
英文关键词	Leucogranite; Highly fractionated granite; Himalayan orogen; North Himalayan Gneiss Dome
语种	英语
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS类目	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:000372383600020
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/258666
推荐引用方式 GB/T 7714	Liu, Zhi-Chao,Wu, Fu-Yuan,Ding, Lin,et al. Highly fractionated Late Eocene (similar to 35 Ma) leucogranite in the Xiaru Dome, Tethyan Himalaya, South Tibet[J]. 中国科学院青藏高原研究所,2016,240.
APA	Liu, Zhi-Chao,Wu, Fu-Yuan,Ding, Lin,Liu, Xiao-Chi,Wang, Jian-Gang,&Ji, Wei-Qiang.(2016).Highly fractionated Late Eocene (similar to 35 Ma) leucogranite in the Xiaru Dome, Tethyan Himalaya, South Tibet.LITHOS,240.
MLA	Liu, Zhi-Chao,et al."Highly fractionated Late Eocene (similar to 35 Ma) leucogranite in the Xiaru Dome, Tethyan Himalaya, South Tibet".LITHOS 240(2016).