中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Zircon U-Pb and Hf isotope constraints from the Ailao Shan-Red River shear zone on the tectonic and crustal evolution of southwestern China

文献类型:期刊论文

作者Lin, Te-Hsien1; Chung, Sun-Lin1; Chiu, Han-Yi1; Wu, Fu-Yuan2; Yeh, Meng-Wan3; Searle, Mike P.4; Iizuka, Yoshiyuki5
刊名CHEMICAL GEOLOGY
出版日期2012-01-06
卷号291页码:23-37
关键词Zircon U-Pb and Lu-Hf isotopes Ailao Shan-Red River shear zone Tectonic evolution Crustal formation South China
ISSN号0009-2541
DOI10.1016/j.chemgeo.2011.11.011
文献子类Article
英文摘要The Ailao Shan-Red River (ASRR) shear zone, one of the most prominent geologic strike-slip shear zones in Southeast Asia, consists of high-grade metamorphic complexes that provide a rare opportunity to sample the mid-crustal rocks along the western margin of the Yangtze Block of South China. Here we report combined, in-situ analyses of zircon U-Pb and Lu-Hf isotopes of eight gneisses from the Diancang Shan and Ailao Shan segments of the ASRR shear zone. Our zircon U-Pb data indicate that the rocks contain abundant magmatic zircons ranging in age from 1785 to 25 Ma, with peak ages at ca. 770, 350 and 240 Ma, suggesting three major periods of protolith formation. The 350-Ma zircons, observed only in an orthogneiss from the Diancang Shan, show uniform initial Hf isotopic ratios marked by high and positive epsilon(Hf)(T) values from +16 to +10. This is in contrast with the other two zircon populations that are more common, occurring in both the Diancang Shan and Ailao Shan, and overall delineate very heterogeneous Hf isotopic compositions, with epsilon(Hf)(T) values ranging from +15 to -16. Many zircons reveal distinctive core-rim age variations. Zircon rims, formed between ca. 34 and 26 Ma, show significant variations in Th/U ratios (5-0.01) and epsilon(Hf)(T) values (+14 to 10) that suggest complicated magmatic and metamorphic zircon overgrowth during the Oligocene. The presence of both metamorphic and magmatic overgrowths on zircons suggests that the metamorphism reached upper amphibolite facies, corresponding to mid-crustal level P-T conditions, as also suggested by structural and petrologic data. Our data furthermore suggest that the ASRR gneisses were not produced solely by shear heating during the Tertiary strike-slip faulting, but are uplifted, mid-crustal basement rocks that formed essentially during two major stages of magmatism, represented by the Neoproterozoic Kangding Complex and Late Permian Emeishan large igneous province. As a result of the India-Asia collision, these basement rocks underwent regional magmatic and metamorphic overprinting in the Oligocene that, based on our relevant work (Searle et al., 2010, Geosphere, 6, 1-23), predated the initial left-lateral movement along the ASRR shear zone. The 350-Ma protolith, which requires a dominant depleted-mantle input in the petrogenesis, cannot be linked to any major magmatic events in South China but may be interpreted as part of the Paleotethys remnants that were later incorporated into the ASRR shear zone. (C) 2011 Elsevier B.V. All rights reserved.
WOS关键词LARGE IGNEOUS PROVINCE ; EMEISHAN FLOOD BASALTS ; WESTERN YANGTZE BLOCK ; LEFT-LATERAL SHEARING ; NAM-DINH AREA ; SOUTH CHINA ; SW CHINA ; SE ASIA ; MANTLE PLUME ; GEOCHEMICAL EVIDENCE
WOS研究方向Geochemistry & Geophysics
语种英语
WOS记录号WOS:000300202300003
出版者ELSEVIER SCIENCE BV
资助机构National Science Council, Taiwan, ROC ; National Science Council, Taiwan, ROC ; National Science Council, Taiwan, ROC ; National Science Council, Taiwan, ROC ; National Science Council, Taiwan, ROC ; National Science Council, Taiwan, ROC ; National Science Council, Taiwan, ROC ; National Science Council, Taiwan, ROC
源URL[http://ir.iggcas.ac.cn/handle/132A11/84272]  
专题中国科学院地质与地球物理研究所
通讯作者Chung, Sun-Lin
作者单位1.Natl Taiwan Univ, Dept Geosci, Taipei 10764, Taiwan
2.Chinese Acad Sci, Inst Geol & Geophys, Beijing, Peoples R China
3.Natl Taiwan Normal Univ, Ctr Gen Educ, Taipei, Taiwan
4.Univ Oxford, Dept Earth Sci, Oxford OX1 3AN, England
5.Acad Sinica, Inst Earth Sci, Taipei 115, Taiwan
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GB/T 7714
Lin, Te-Hsien,Chung, Sun-Lin,Chiu, Han-Yi,et al. Zircon U-Pb and Hf isotope constraints from the Ailao Shan-Red River shear zone on the tectonic and crustal evolution of southwestern China[J]. CHEMICAL GEOLOGY,2012,291:23-37.
APA Lin, Te-Hsien.,Chung, Sun-Lin.,Chiu, Han-Yi.,Wu, Fu-Yuan.,Yeh, Meng-Wan.,...&Iizuka, Yoshiyuki.(2012).Zircon U-Pb and Hf isotope constraints from the Ailao Shan-Red River shear zone on the tectonic and crustal evolution of southwestern China.CHEMICAL GEOLOGY,291,23-37.
MLA Lin, Te-Hsien,et al."Zircon U-Pb and Hf isotope constraints from the Ailao Shan-Red River shear zone on the tectonic and crustal evolution of southwestern China".CHEMICAL GEOLOGY 291(2012):23-37.

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来源:地质与地球物理研究所

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