Eocene high grade metamorphism and crustal anatexis in the North Himalaya Gneiss Domes, Southern Tibet

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	Eocene high grade metamorphism and crustal anatexis in the North Himalaya Gneiss Domes, Southern Tibet
	Gao, LE (Gao LiE); Zeng, LS (Zeng LingSen); Xie, KJ (Xie KeJia)
刊名	CHINESE SCIENCE BULLETIN
	2012
卷号	57 期号:6 页码:639-650
关键词	Tibet Himalayan orogenic belt North Himalayan Gneiss Domes high-grade metamorphism crustal anatexis
ISSN号	1001-6538
英文摘要	Determination of the timing and geochemical nature of early metamorphic and anatectic events in the Himalayan orogen may provide key insights into the physical and chemical behavior of lower crustal materials during the early stage of tectonic evolution in large-scale collisional belts. The Yardoi gneiss dome is the easternmost dome of the North Himalayan Gneiss Domes (NHGD), and contains three types of amphibolites with distinct mineral assemblage, elemental and radiogenic isotope geochemistry, as well as various types of gneisses. SHRIMP zircon U/Pb analyses on the garnet amphibolite and garnet-bearing biotite granitic gneiss yield ages of nearly peak metamorphism at 45.0 +/- 1.0 Ma and 47.+/- 1.8 Ma, respectively, which are 2 to 4 Ma older than the age for partial melting in migmatitic garnet amphibolite (43.5 +/- 1.3 Ma). Available data have demonstrated that ultra-high pressure metamorphism in the Tethyan Himalaya occurred at similar to 55 Ma, and high amphibolite facies to granulite facies metamorphism at 45 to 47 Ma. In addition, partial melting at thickened crustal conditions occurred at 43.5 +/- 1.3 Ma, which led to the formation of high Sr/Y ratios two-mica granites. The high-grade metamorphic rocks in the NHGD may represent the subducted front of the Indian continental lithosphere. In large collisional belts, fertile components in crustal materials could melt and form granitic melts with relatively high Na/K and Sr/Y ratios under thickened crustal conditions, significantly different from those formed by decompressional melting during rapid exhumation.
学科主题	变质岩岩石学
WOS关键词	INDIA-ASIA COLLISION ; ULTRAHIGH-PRESSURE METAMORPHISM ; PB ZIRCON AGES ; U-PB ; CONTINENTAL-CRUST ; GEOCHEMICAL CONSTRAINTS ; GEOLOGICAL IMPLICATIONS ; TETHYAN HIMALAYA ; OROGENIC BELT ; SLAB BREAKOFF
WOS研究方向	Science & Technology - Other Topics
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000299924600013
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39637]
专题	中国地质调查局
作者单位	Nonferrous Mineral Explorat Engn Res Ctr Henan Pr, Zhengzhou 450016, Peoples R China
推荐引用方式 GB/T 7714	Gao, LE ,Zeng, LS ,Xie, KJ . Eocene high grade metamorphism and crustal anatexis in the North Himalaya Gneiss Domes, Southern Tibet[J]. CHINESE SCIENCE BULLETIN,2012,57(6):639-650.
APA	Gao, LE ,Zeng, LS ,&Xie, KJ .(2012).Eocene high grade metamorphism and crustal anatexis in the North Himalaya Gneiss Domes, Southern Tibet.CHINESE SCIENCE BULLETIN,57(6),639-650.
MLA	Gao, LE ,et al."Eocene high grade metamorphism and crustal anatexis in the North Himalaya Gneiss Domes, Southern Tibet".CHINESE SCIENCE BULLETIN 57.6(2012):639-650.