中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
首页 机构 成果 学者
  
  1. CAS IR Grid
  2. 地质与地球物理研究所
  3. 中国科学院地质与地球物理研究所
Origin of TTG-like rocks from anatexis of ancient lower crust: Geochemical evidence from Neoproterozoic granitoids in South China

文献类型：期刊论文

作者Zhang, Shao-Bing1; Zheng, Yong-Fei1; Zhao, Zi-Fu1; Wu, Yuan-Bao4; Yuan, Honglin3; Wu, Fu-Yuan2
刊名LITHOS
出版日期2009-12-01
卷号113期号:3-4页码:347-368
关键词Zircon Hf isotope Source inheritance TTG Granitoid Crustal anatexis
ISSN号0024-4937
DOI10.1016/j.lithos.2009.04.024
文献子类Article
英文摘要TTG rocks are commonly assumed to form by partial melting of oceanic crust during slab subduction or anatexis of thickened lower crust. The two models are tested by an integrated study of geochronology and geochemistry for a composite batholith of Neoproterozoic granitoids (mainly TTG-like) from the Yangtze Gorge in South China. Zircon U-Pb dating indicates that all granitoids crystallized in a period of 820 to 800 Ma. Zircon delta(18)O values are 4.85 to 6.84 parts per thousand, suggesting limited contributions from supracrustal materials to magma sources. Zircon epsilon(Hf)(t) values for syn-magmatic domains range from -3.6 to -29.7, concordant with whole-rock epsilon(Nd)(t) values of -2.1 to -21.3. Correspondingly, zircon Hf model ages are 2.09 to 3.16 Ga, suggesting their derivation from ancient crust of Paleoproterozoic to Archean ages. TTG-like rocks contain inherited zircon cores that yield two groups of U-Pb ages at Paleoproterozoic (1.8 to 2.0 Ga) and Archean (similar to 2.9 Ga), respectively. They show variable epsilon(Hf)(t) values from -48.4 to -33.4. Because the Neoproterozoic magmatism leads to variable increases of epsilon(Hf)(t) values for some inherited cores, only the lowest epsilon(Hf)(t) values for the inherited cores are assumed to represent the original Hf isotopes in source rocks. The screened results are consistent with those for Archean TTG gneiss and migmatite in this region. In addition, the TTG-like rocks have lower epsilon(Nd)(t) and epsilon(Hf)(t) values, higher Sr/Y and (La/Yb)(N) ratios and stronger depletion in Nb, Ta and Ti than the other granitoids. Two alternative scenarios are proposed to account for their petrogenesis: (1) anatexis of Archean and Paleoproterozoic mafic crust in the stable depths of garnet and amphibole, respectively; or (2) anatexis of Archean TTG and Paleoproterozoic mafic rocks in amphibole-stable depths. Nevertheless, the second one is preferred because the inherited zircons with Paleoproterozoic to Archean U-Pb ages are preserved in the TTG-like rocks, which is incompatible with high temperatures to generate the primary TTG magmas. Therefore, the Neoproterozoic TTG-like rocks were derived from the anatexis of ancient non-thickened lower crust, with the TTG features inheriting from their source. (C) 2009 Elsevier B.V. All rights reserved.
WOS关键词OXYGEN-ISOTOPE FRACTIONATION ; EARLY CONTINENTAL-CRUST ; ZIRCON U-PB ; TRONDHJEMITE-GRANODIORITE TTG ; YANGTZE CRATON ; ARCHEAN CRUST ; EXPERIMENTAL CONSTRAINTS ; PHASE-RELATIONSHIPS ; PRECAMBRIAN CRUST ; SUPERIOR PROVINCE
WOS研究方向Geochemistry & Geophysics ; Mineralogy
语种英语
WOS记录号WOS:000272787200001
出版者ELSEVIER SCIENCE BV
资助机构Chinese Academy of Sciences(KZCX2-YW-Q08) ; Chinese Academy of Sciences(KZCX2-YW-Q08) ; Natural Science Foundation of China(40803005) ; Natural Science Foundation of China(40803005) ; Chinese Academy of Sciences(KZCX2-YW-Q08) ; Chinese Academy of Sciences(KZCX2-YW-Q08) ; Natural Science Foundation of China(40803005) ; Natural Science Foundation of China(40803005) ; Chinese Academy of Sciences(KZCX2-YW-Q08) ; Chinese Academy of Sciences(KZCX2-YW-Q08) ; Natural Science Foundation of China(40803005) ; Natural Science Foundation of China(40803005) ; Chinese Academy of Sciences(KZCX2-YW-Q08) ; Chinese Academy of Sciences(KZCX2-YW-Q08) ; Natural Science Foundation of China(40803005) ; Natural Science Foundation of China(40803005)
源URL[http://ir.iggcas.ac.cn/handle/132A11/70480]  
专题中国科学院地质与地球物理研究所
通讯作者Zhang, Shao-Bing
作者单位1.Univ Sci & Technol China, CAS Key Lab Crust Mantle Mat & Environm, Sch Earth & Space Sci, Hefei 230026, Peoples R China
2.Chinese Acad Sci, State Key Lab Lithospher Evolut, Inst Geol & Geophys, Beijing 100029, Peoples R China
3.NW Univ Xian, State Kay Lab Continental Dynam, Dept Geol, Xian 710069, Peoples R China
4.China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Fac Earth Sci, Wuhan 430074, Peoples R China
推荐引用方式
GB/T 7714		 Zhang, Shao-Bing,Zheng, Yong-Fei,Zhao, Zi-Fu,et al. Origin of TTG-like rocks from anatexis of ancient lower crust: Geochemical evidence from Neoproterozoic granitoids in South China[J]. LITHOS,2009,113(3-4):347-368.
APA Zhang, Shao-Bing,Zheng, Yong-Fei,Zhao, Zi-Fu,Wu, Yuan-Bao,Yuan, Honglin,&Wu, Fu-Yuan.(2009).Origin of TTG-like rocks from anatexis of ancient lower crust: Geochemical evidence from Neoproterozoic granitoids in South China.LITHOS,113(3-4),347-368.
MLA Zhang, Shao-Bing,et al."Origin of TTG-like rocks from anatexis of ancient lower crust: Geochemical evidence from Neoproterozoic granitoids in South China".LITHOS 113.3-4(2009):347-368.

入库方式： OAI收割

来源：地质与地球物理研究所

浏览0
下载0
收藏0
其他版本

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。