Highly fractionated Late Eocene (similar to 35 Ma) leucogranite in the Xiaru Dome, Tethyan Himalaya, South Tibet

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
	Wang, JG (Wang, Jian-Gang)3; Ji, WQ (Ji, Wei-Qiang)3; Liu, ZC ; Liu, ZC (Liu, Zhi-Chao)1,2,3; Wu, FY (Wu, Fu-Yuan)3; Ding, L (Ding, Lin)2; Liu, XC (Liu, Xiao-Chi)3
刊名	LITHOS
	2016
卷号	240-243 期号:0 页码:337-354
关键词	Malashan Gneiss Dome U-pb Geochronology Lachlan Fold Belt A-type Granites Tectonic Evolution Crustal Anatexis Geological Implications Peraluminous Granite Trace-elements Geochemical Constraints
DOI	10.1016/j.lithos.2015.11.026
文献子类	Article
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.
学科主题	地质学
语种	英语
WOS记录号	WOS:000372383600020
内容类型	期刊论文
源URL	[http://ir.itpcas.ac.cn/handle/131C11/7871]
专题	青藏高原研究所_图书馆
通讯作者	Liu, ZC
作者单位	1.Sun Yat Sen Univ, Sch Earth Sci & Geol Engn, Guangzhou 510275, Guangdong, Peoples R China 2.Chinese Acad Sci, Inst Tibetan Plateau Res, Beijing 100101, Peoples R China 3.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Wang, JG ,Ji, WQ ,Liu, ZC,et al. Highly fractionated Late Eocene (similar to 35 Ma) leucogranite in the Xiaru Dome, Tethyan Himalaya, South Tibet[J]. LITHOS,2016,240-243(0):337-354.
APA	Wang, JG .,Ji, WQ .,Liu, ZC.,Liu, ZC .,Wu, FY .,...&Liu, XC .(2016).Highly fractionated Late Eocene (similar to 35 Ma) leucogranite in the Xiaru Dome, Tethyan Himalaya, South Tibet.LITHOS,240-243(0),337-354.
MLA	Wang, JG ,et al."Highly fractionated Late Eocene (similar to 35 Ma) leucogranite in the Xiaru Dome, Tethyan Himalaya, South Tibet".LITHOS 240-243.0(2016):337-354.