Geochemistry, zircon U - Pb geochronology and Lu - Hf isotopic;composition of eclogites and their host gneisses in the Dulan area,;North Qaidam UHP terrane: New evidence for deep continental subduction

doi:10.1016/j.gr.2012.07.018

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	Geochemistry, zircon U - Pb geochronology and Lu - Hf isotopic;composition of eclogites and their host gneisses in the Dulan area,;North Qaidam UHP terrane: New evidence for deep continental subduction
	Yu, Shengyao 5; Zhang, Jianxin ; Li, Huaikun 1; Hou, Kejun 2; Mattinson, C. G.; Gong, Jianghua
刊名	GONDWANA RESEARCH
	2013
卷号	23 期号:3;SI SI 页码:901-919
关键词	North Qaidam UHP terrane Eclogite Zircon U - Pb geochronology Lu - Hf isotopes Whole-rock geochemistry
ISSN号	1342-937X;EI 1878-0571
DOI	10.1016/j.gr.2012.07.018
英文摘要	In this study, we link zircon U-Pb SHRIMP and LA-ICP-MS geochronology and the Lu-Hf isotopic composition of edogites and their host gneisses/schists with whole-rock geochemistry of eclogites in the Dulan area to constrain their protoliths and metamorphic relationships. U-Pb dating suggests that the protolith of one of the eclogites was a Neoproterozoic mafic intrusive rock (828 +/- 58 Ma) and the protolith of enclosing orthogneiss was an early-Neoproterozoic granitoid (923 +/- 12 Ma). Detrital zircons from Grt-bearing mica-schists yield ages of 0.9-2.5 Ga, with a dominant range of 1.0-1.8 Ga, indicating sedimentary sources from Neoproterozoic to Neoarchean crust and a depositional age <= 0.9 Ga. The matching metamorphic ages of eclogites (438 +/- 5 Ma, 436 +/- 4 Ma) and their country rocks (Grt-bearing mica-schists: 438 +/- 4 Ma, 439 +/- 8 Ma; orthogneiss: 427 +/- 8 Ma) indicate that all studied samples experienced coeval Early Paleozoic HP/UHP metamorphism. The U-Pb ages and Hf isotopic compositions of the inherited magmatic zircon cores of an eclogite sample (epsilon(HF) (800)=2.6-9.2, T-DM1 = 1.0-1.3 Ga, T-DM2 = 1.1-1.4 Ga) suggest that the protolith may be derived from Neoproterozoic depleted mantle with variable proportions of an older crustal component. The magmatic zircon cores of the orthogneiss (epsilon(Hf) (900) = -7.3 to 00.2; T-DM2 = 1.8-2.1 Ga) suggest that the parental magma was derived from a Paleoproterozoic crustal source. Hf isotopic compositions of the detrital zircons from the metasediments (epsilon(Hf)(t) = 19.4 to +10.6) suggest three crust formation and reworking events: (1) Archean (T-DM2 = 2.7-2.9 Ga) juvenile crust reworked at similar to 2.5 Ga; (2) early Paleoproterozoic (T-DM2 = 2.3-2.5 Ga) juvenile crust reworked at similar to 1.8 Ga; and (3) late Paleoproterozoic (T-DM2 = 1.5-1.9 Ga) juvenile crust reworked in the Neoproterozoic.;Whole-rock geochemical data suggest that the protoliths of the Dulan eclogites were probably derived from a continental rift or an incipient oceanic basin rather than a large, long-lived ocean basin. Thus, combined with field relationships, petrology, geochemistry, zircon U-Pb dating and the Lu-Hf isotopic analysis presented in this paper and reported from previous studies, we suggest that the Dulan eclogites and their country rocks experienced a common UHP metamorphism during Late Ordovician deep continental subduction. (C) 2012 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
学科主题	变质岩岩石学
WOS关键词	ULTRAHIGH-PRESSURE METAMORPHISM ; PLASMA-MASS SPECTROMETRY ; HIGH-GRADE ; METAMORPHISM ; IN-SITU ANALYSIS ; NW CHINA ; WESTERN CHINA ; TIBETAN ; PLATEAU ; TRACE-ELEMENT ; LASER-ABLATION ; HP/UHP TERRANE
WOS研究方向	Geology
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000315543400005
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40084]
专题	中国地质调查局天津地质调查中心
作者单位	1.Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China. 2.CGS, Tianjin Inst Geol & Mineral Resources, Tianjin 300170, Peoples R China. 3.Chinese Acad Geol Sci, Inst Mineral Resources, Beijing 100037, Peoples R China. 4.Mattinson, C. G.] Cent Washington Univ, Dept Geol Sci, Ellensburg, WA 98926 USA. 5.中国地质科学院地质研究所
推荐引用方式 GB/T 7714	Yu, Shengyao,Zhang, Jianxin,Li, Huaikun,et al. Geochemistry, zircon U - Pb geochronology and Lu - Hf isotopic;composition of eclogites and their host gneisses in the Dulan area,;North Qaidam UHP terrane: New evidence for deep continental subduction[J]. GONDWANA RESEARCH,2013,23(3;SI SI):901-919.
APA	Yu, Shengyao,Zhang, Jianxin,Li, Huaikun,Hou, Kejun,Mattinson, C. G.,&Gong, Jianghua.(2013).Geochemistry, zircon U - Pb geochronology and Lu - Hf isotopic;composition of eclogites and their host gneisses in the Dulan area,;North Qaidam UHP terrane: New evidence for deep continental subduction.GONDWANA RESEARCH,23(3;SI SI),901-919.
MLA	Yu, Shengyao,et al."Geochemistry, zircon U - Pb geochronology and Lu - Hf isotopic;composition of eclogites and their host gneisses in the Dulan area,;North Qaidam UHP terrane: New evidence for deep continental subduction".GONDWANA RESEARCH 23.3;SI SI(2013):901-919.