Fluid action on zircon growth and recrystallization during quartz veining within UHP eclogite: Insights from U-Pb ages, O-Hf isotopes and trace elements

doi:10.1016/j.lithos.2011.06.012

	Fluid action on zircon growth and recrystallization during quartz veining within UHP eclogite: Insights from U-Pb ages, O-Hf isotopes and trace elements
	Sheng, Ying-Ming 1; Zheng, Yong-Fei 1; Chen, Ren-Xu 1; Li, Qiuli 2; Dai, Mengning 3
刊名	LITHOS
	2012-04-01
卷号	136 页码:126-144
关键词	Metamorphic fluid Xenocrystal zircon O isotope U-Pb age Trace element Quartz vein Eclogite Continental collision
ISSN号	0024-4937
DOI	10.1016/j.lithos.2011.06.012
文献子类	Article
英文摘要	In-situ SIMS analyses of O and U-Pb isotopes as well as LA-(MC)-ICPMS analyses of trace elements, U-Pb, and Lu-Hf isotopes were carried out for zircon from a quartz vein and its host UHP eclogite in the Dabie orogen. The results are integrated to decipher the effect of aqueous fluid on the new growth of metamorphic zircon and on the recrystallization of protolith zircon during continental subduction-zone metamorphism. Most zircons show distinct core-(mantle)-rim structures in CL images. The rims are unzoned and have low trace element contents, low Th/U ratios of 0.003 to 0.06 and shallow MREE-HREE patterns, and insignificant negative Eu anomalies, indicating their growth from metamorphic fluid. The rims from the vein have concordant U-Pb ages of 222 +/- 6 to 212 +/- 4 Ma, suggesting protracted growth during exhumation of the deeply subducted continental crust. In contrast, the rims from the eclogite gave two groups of concordant UPb ages at 221 +/- 3 and 208 +/- 3 Ma, respectively, corresponding to two episodes of fluid action. The all rims have relatively uniformly negative delta O-18 values of -2.59 to -1.23%. for the vein and -3.37 to -0.33%, for the eclogite, suggesting their growth from negative delta O-18 metamorphic fluids of the same origin. The cores exhibit clearly oscillatory or patchy zonation, high trace element contents, high Th/U ratios of 0.13 to 2.12, steep MREE-HREE patterns, and significant negative Eu anomalies. They gave discordia Neoproterozoic upper-intercept U-Pb ages for the both vein and eclogite. Most cores have discordant U-Pb ages and variably positive 8180 values, with no correlation between the two variables. This suggests non-linear isotope alteration of the protolith zircon by metamorphic recrystallization in the presence of aqueous fluid. The highest delta O-18 value of 4.76% with the concordant Neoproterozoic U-Pb age is considered as a proxy for the primary delta O-18 value for the protolith zircon. In this regard, the cores would crystallize from slightly low delta O-18 magmas in the Neoproterozoic, and interacted with the negative delta O-18 fluids of metamorphic origin in the Triassic. In particular, the cores in the vein are the xenocrystal that was trapped by the metamorphic fluids from the eclogite. Therefore, the occurrence of the both magmatic cores and metamorphic growth in the vein suggests that sinking of the metamorphic fluids into eclogite factures brought about both the physical transport of protolith zircon and the chemical transport of element Zr during the continental collision. (C) 2011 Elsevier B.V. All rights reserved.
WOS关键词	PRESSURE METAMORPHIC ROCKS ; HIGH-GRADE METAMORPHISM ; NEOPROTEROZOIC RIFT MAGMATISM ; SUBDUCTION-ZONE METAMORPHISM ; SCIENTIFIC-DRILLING PROJECT ; COESITE-BEARING ECLOGITE ; CENTRAL-EASTERN CHINA ; TI-IN-ZIRCON ; OXYGEN-ISOTOPE ; DABIE OROGEN
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000302517900009
资助机构	National Ministry of Science and Technology(2009CB825004) ; National Ministry of Science and Technology(2009CB825004) ; Natural Science Foundation of China(40921002 ; Natural Science Foundation of China(40921002 ; Fundamental Research Funds for the Central Universities ; Fundamental Research Funds for the Central Universities ; 40973004 ; 40973004 ; 40830318 ; 40830318 ; 40703002) ; 40703002) ; National Ministry of Science and Technology(2009CB825004) ; National Ministry of Science and Technology(2009CB825004) ; Natural Science Foundation of China(40921002 ; Natural Science Foundation of China(40921002 ; Fundamental Research Funds for the Central Universities ; Fundamental Research Funds for the Central Universities ; 40973004 ; 40973004 ; 40830318 ; 40830318 ; 40703002) ; 40703002) ; National Ministry of Science and Technology(2009CB825004) ; National Ministry of Science and Technology(2009CB825004) ; Natural Science Foundation of China(40921002 ; Natural Science Foundation of China(40921002 ; Fundamental Research Funds for the Central Universities ; Fundamental Research Funds for the Central Universities ; 40973004 ; 40973004 ; 40830318 ; 40830318 ; 40703002) ; 40703002) ; National Ministry of Science and Technology(2009CB825004) ; National Ministry of Science and Technology(2009CB825004) ; Natural Science Foundation of China(40921002 ; Natural Science Foundation of China(40921002 ; Fundamental Research Funds for the Central Universities ; Fundamental Research Funds for the Central Universities ; 40973004 ; 40973004 ; 40830318 ; 40830318 ; 40703002) ; 40703002)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/84188]
专题	中国科学院地质与地球物理研究所
通讯作者	Sheng, Ying-Ming
作者单位	1.Univ Sci & Technol China, Sch Earth & Space Sci, CAS Key Lab Crust Mantle Mat & Environm, Hefei 230026, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 3.NW Univ Xian, Dept Geol, State Key Lab Continental Dynam, Xian 710069, Peoples R China
推荐引用方式 GB/T 7714	Sheng, Ying-Ming,Zheng, Yong-Fei,Chen, Ren-Xu,et al. Fluid action on zircon growth and recrystallization during quartz veining within UHP eclogite: Insights from U-Pb ages, O-Hf isotopes and trace elements[J]. LITHOS,2012,136:126-144.
APA	Sheng, Ying-Ming,Zheng, Yong-Fei,Chen, Ren-Xu,Li, Qiuli,&Dai, Mengning.(2012).Fluid action on zircon growth and recrystallization during quartz veining within UHP eclogite: Insights from U-Pb ages, O-Hf isotopes and trace elements.LITHOS,136,126-144.
MLA	Sheng, Ying-Ming,et al."Fluid action on zircon growth and recrystallization during quartz veining within UHP eclogite: Insights from U-Pb ages, O-Hf isotopes and trace elements".LITHOS 136(2012):126-144.