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DOI	10.1016/j.lithos.2010.03.006
	Evolution of the Luliangshan garnet peridotites in the North Qaidam UHP belt, Northern Tibetan Plateau: Constraints from Re-Os isotopes
	Shi, R. D.; Griffin, W. L.; O'Reilly, S. Y.; Zhao, G. C.; Huang, Q. S.; Li, J.; Xu, J. F.
通讯作者	Shi, RD (通讯作者)
发表日期	2010
ISSN	0024-4937
EISSN	1872-6143
起始页码	307
结束页码	321
卷号	117 期号:1-4
英文摘要	Garnet pendotite. interlayered with lesser amounts of dunite and olivine websterite and interwoven with garnet pyroxenite dikes, makes up a 0.5 km(2) massif near Luliangshan in the North Qaidam ultrahigh-pressure (UHP) metamorphic belt, Northern Tibetan Plateau Previous studies have suggested that the garnet peridontes represent Alaskan-style magmatic cumulates or oceanic serpentirutes that were subducted to depths of >200 km. Re-Os isotopic data provide new constraints on the origin and formation of the pendotites Most dunites (Mg# 92 -> 95) have high Os contents (2.90-4.25 ppb) and low Os-187/Os-188 (minimum 0 1108), while garnet pyroxenites have high Os-187/Os-188 (up to 0.2847) and low Os contents (0.03-1 ppb), garnet Iherzolites lie between these extremes The Archean model ages (TRD = 2.6 Ga, TMA = 28 Ga) of the most refractory dunites represent minimum estimates for the age of the original melt depletion. In an Os-Os-187/Os-188 plot, almost all garnet peridotites fall along two mixing lines: one is defined by mixing between the most refractory dunite and a garnet-rich pyroxenite, and the other by mixing between the dunite and a garnet-poor pyroxenite The extremely depleted nature of the dunites, the high Ca and Al contents of the Iherzolites, the variable enrichment in incompatible elements, and the Re-Os isotopic data suggest that the Luliangshan garnet peridotites represent a fragment of subcontinental mantle, in which ancient residues after melt extraction (e.g. dunite) were refertilised by mafic melts similar to the garnet pyroxenites Modelling of the garnet peridotite data suggests that at least some of the metasomatism is Paleoproterozoic in age. Re also may have been introduced into some of the garnet peridotites during the Paleozoic UHP Qaidam orogeny The Luliangshan peridotites are interpreted as refertilised Archean subcontinental lithospheric mantle, probably derived from beneath the North China Craton and entrained in the surrounding gneisses during their subduction into the mantle; the garnet peridotite assemblages may have formed during the original refertilisation event, or during the subduction. (C) 2010 Elsevier BV All rights reserved
关键词	PRESSURE METAMORPHIC BELT LITHOSPHERIC MANTLE BENEATH WESTERN GNEISS REGION GEOCHEMICAL CONSTRAINTS ARCHEAN MANTLE PB ISOTOPE CHINA ORIGIN XENOLITHS MELT
英文关键词	Re-Os isotope; Garnet peridotite; North Qaidam; Tibetan Plateau; Mantle refertilisation
语种	英语
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS类目	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:000278731800020
来源期刊	LITHOS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/257796
推荐引用方式 GB/T 7714	Shi, R. D.,Griffin, W. L.,O'Reilly, S. Y.,et al. Evolution of the Luliangshan garnet peridotites in the North Qaidam UHP belt, Northern Tibetan Plateau: Constraints from Re-Os isotopes[J]. 中国科学院青藏高原研究所,2010,117(1-4).
APA	Shi, R. D..,Griffin, W. L..,O'Reilly, S. Y..,Zhao, G. C..,Huang, Q. S..,...&Xu, J. F..(2010).Evolution of the Luliangshan garnet peridotites in the North Qaidam UHP belt, Northern Tibetan Plateau: Constraints from Re-Os isotopes.LITHOS,117(1-4).
MLA	Shi, R. D.,et al."Evolution of the Luliangshan garnet peridotites in the North Qaidam UHP belt, Northern Tibetan Plateau: Constraints from Re-Os isotopes".LITHOS 117.1-4(2010).