Provenance and age of gneisses in the Dulan area, North Qaidam UHP metamorphic belt Evidence from zircon U-Pb geochronology, REE and Hf isotopic analyses.

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	Provenance and age of gneisses in the Dulan area, North Qaidam UHP metamorphic belt Evidence from zircon U-Pb geochronology, REE and Hf isotopic analyses.
	Yu, SY (Yu ShengYao); Zhang, JX (Zhang JianXin)
刊名	ACTA PETROLOGICA SINICA
	2010
卷号	26 期号:7 页码:2083-2098
关键词	Dulan Gneiss Zircon U-Pb dating Lu-Hf isotope
ISSN号	1000-0569
英文摘要	In the eastern part of the North Qaidam HP/UHP metamorphic belt, near Dulan, orthogneiss and paragneiss enclose minor eclogites and ultramafic rocks. Although showing a common amphibolite-facies metamorphism overprint, field relationship and coesite inclusion in gneiss indicates that both gneiss and eclogite experienced UHP metamorphism. In this study, we link U-Pb age, trace element analyses and Hf isotope composition to unravel the provenance and possible metamorphic age of two gneisses. The combination of cathodoluminescence (CL) image, trace element analyses and U-Pb age reveals that the zircon retains distinct core, mantle and rim. Zircon cores yield ages of 2322 similar to 2365Ma, suggesting an Early Paleoproterozoic magmatic event in the source area. Zircon mantle gives upper intercept ages of 1830 similar to 1837Ma, indicating that the gneisses experienced metamorphism and anatexis in Late Paleoproterozoic time. Zircon rim gives lower intercept ages of 451 similar to 465Ma consistent with Ordovician eclogite facies metamorphism previously determined from eclogite and paragneiss. The negative epsilon(Hf)(t) values of both Early Paleoproterozic detrital zircon cores and Late Paleoproterozic metamorphic/anatectic zircon mantles and corresponding Archean model ages (2.73 similar to 2.84Ga) imply a crust growth at Neoarchean and experienced two episodes of reworking events during Paleoproterozoic. This is similar to the Archean-Paleoproterozoic history of crust evolution decribed in the Oulongbuluke microcontinent to the north of the Dulan area, but gneisses from Dulan area experienced deep subduction together with enclosed eclogite during Early Paleozoic era.
学科主题	变质岩岩石学
WOS关键词	WESTERN CHINA ; TIBETAN PLATEAU ; NW CHINA ; LASER-ABLATION ; HP/UHP TERRANE ; TRACE-ELEMENT ; HIGH-PRESSURE ; GEOLOGICAL SIGNIFICANCE ; CONTINENTAL COLLISION ; CRUSTAL EVOLUTION
WOS研究方向	Geology
语种	中文
出版者	SCIENCE CHINA PRESS
WOS记录号	WOS:000280658100010
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39164]
专题	中国地质调查局
作者单位	Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China
推荐引用方式 GB/T 7714	Yu, SY ,Zhang, JX . Provenance and age of gneisses in the Dulan area, North Qaidam UHP metamorphic belt Evidence from zircon U-Pb geochronology, REE and Hf isotopic analyses.[J]. ACTA PETROLOGICA SINICA,2010,26(7):2083-2098.
APA	Yu, SY ,&Zhang, JX .(2010).Provenance and age of gneisses in the Dulan area, North Qaidam UHP metamorphic belt Evidence from zircon U-Pb geochronology, REE and Hf isotopic analyses..ACTA PETROLOGICA SINICA,26(7),2083-2098.
MLA	Yu, SY ,et al."Provenance and age of gneisses in the Dulan area, North Qaidam UHP metamorphic belt Evidence from zircon U-Pb geochronology, REE and Hf isotopic analyses.".ACTA PETROLOGICA SINICA 26.7(2010):2083-2098.