U-Pb dating for garnet-rich granite veins in high-pressure granulites from the Namche Barwa complex, eastern syntaxis of the Himalayas, and the relationship with exhumation

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	U-Pb dating for garnet-rich granite veins in high-pressure granulites from the Namche Barwa complex, eastern syntaxis of the Himalayas, and the relationship with exhumation
	Qi, XX (Qi XueXiang); Li, HQ (Li HuaQi); Li, TF (Li TianFu); Cai, ZH (Cai ZhiHui); Yu, CL (Yu ChunLin)
刊名	ACTA PETROLOGICA SINICA
	2010
卷号	26 期号:3 页码:975-984
关键词	Garnet-rich granite Zircon SHRIMP U-Pb elating Namche Barwa complex Eastern syntaxis
ISSN号	1000-0569
英文摘要	The Namche Barwa complex, located at the core of the eastern syntaxis of the Himalayan orogenic belt, has been subjected to the high-pressure granulite-grade metamorphism, amphibolite-grade retrogressive metamorphism and inigmatization, and is the metamorphic rocks with high-pressure granulite lens or interlens. The major and trace element data of the garnet-rich granite in the retrogressive granulite show that (I) they are high potassium, aluminum-rich; (2) they are strongly enriched in [BEE with high fractional degree, depleted in HRH, and enriched in 1,111 and RHE relative to primordial mantle; (3) they have substantial negative En anomalies, and Rb/Sr >1.4. The magmatic initial temperature are ranging from 792 C to 801 C estimated by the major data and Zr contents for garnet-rich granite, which is lower than the peak metamorphic temperature ( 850 C). The zircon SHRIMP U-Pb dating show that (1) the ages for the inherited cores are ranging from 519Ma to 525Ma, exhibit the Namche Barwa complex rocks had been influenced in the pan-African movement; (2) the latest growth rim of zircon grains have three stage ages of 39 4-4 Ma. 24 25 Ma and 7. 3Ma, the first is the forming time of garnet-rich granite veins, the second shows the following MCI. and STDS tectonic event in later Oligocene, and the last indicates the tectonic-surficial feedback information in later Miocene. To sum up, the garnet-rich granite veins in the retrogressive granulite are high-K, peraluminous calc-alkaline granite, formed by fluid-absent partial melting of the lower crust under the condition of isothermally decompression during rapid exhumation of the Namche Barwa complex, and the exhumation of Namche Barwa complex followed on the heel of the peak metamorphism. The garnet-rich granite had been changed during the movement of STDS and MCT, and tectonic-surficial feedback.
学科主题	构造地质学
WOS关键词	ZIRCON SATURATION ; EVOLUTION ; CONSTRAINTS ; TIBET ; INDIA
WOS研究方向	Geology
语种	中文
出版者	SCIENCE CHINA PRESS
WOS记录号	WOS:000276676700026
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39187]
专题	中国地质调查局
作者单位	Beijing Bur Geol & Mineral Survey Explorat & Dev, Beijing 100050, Peoples R China
推荐引用方式 GB/T 7714	Qi, XX ,Li, HQ ,Li, TF ,et al. U-Pb dating for garnet-rich granite veins in high-pressure granulites from the Namche Barwa complex, eastern syntaxis of the Himalayas, and the relationship with exhumation[J]. ACTA PETROLOGICA SINICA,2010,26(3):975-984.
APA	Qi, XX ,Li, HQ ,Li, TF ,Cai, ZH ,&Yu, CL .(2010).U-Pb dating for garnet-rich granite veins in high-pressure granulites from the Namche Barwa complex, eastern syntaxis of the Himalayas, and the relationship with exhumation.ACTA PETROLOGICA SINICA,26(3),975-984.
MLA	Qi, XX ,et al."U-Pb dating for garnet-rich granite veins in high-pressure granulites from the Namche Barwa complex, eastern syntaxis of the Himalayas, and the relationship with exhumation".ACTA PETROLOGICA SINICA 26.3(2010):975-984.