Whole-rock Ar-Ar dating for low-grade metavolcanics within the Dabie orogen and its geological signiflcance
文献类型:期刊论文
作者 | Gao Tianshan; Tang Jiafu; Sang Haiqing; Hu Shiling; Qian Cunchao |
刊名 | CHINESE SCIENCE BULLETIN
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出版日期 | 2006-06-01 |
卷号 | 51期号:12页码:1494-1500 |
关键词 | tuff crust detachment neoproterozoic continental subduction |
ISSN号 | 1001-6538 |
DOI | 10.1007/s11434-006-1494-5 |
文献子类 | Article |
英文摘要 | The genetic relationship between low-grade and ultrahigh-pressure (UHP) metamorphic units in the interior of the Dabie orogen has been controversial with respect to preservation of volcanic texture during continental subduction to mantle depths. In order to resolve this issue, whole-rock Ar-Ar dating was carried out for greenschist-facies metatuff that is in contact with UHP eclogite in Yuexi County, Anhui Province. One sample gave a plateau age of 784.4 +/- 2.0 Ma and an isochron age of 785.0 +/- 4.7 Ma, and the other sample a plateau age of 770.9 +/- 2.0 Ma and an isochron age of 769.5 +/- 3.1 Ma. It appears that the Ar isotopic system was not disturbed since the volcanic eruption at the middle Neoproterozoic. Because of the low closure temperature of Ar diffusion in volcanic rocks, retention of the Neoproterozoic ages indicates that the low-grade metavolcanics did not experience high-grade metamorphism up to eclogite-facies conditions during the Triassic subduction of continental crust. Furthermore the Neoproterozoic Ar-Ar ages are also in agreement with protolith ages of UHP metaigneous rocks in the Dabie orogen. Therefore, the metatuff is interpreted as a tectonic relict that was scraped off during the Triassic subduction and thus was not subducted to mantle depths like the adjacent eclogite. This lends support to the model for crustal detachment between cover and basement during continental collision. A tectonic melange model is proposed to explain the occurrence of contrasting grades of metamorphic rock within the UHP metamorphic zone. |
WOS关键词 | PRESSURE METAMORPHIC ROCKS ; CANADIAN APPALACHIANS ; ACCRETIONARY WEDGES ; CONTINENTAL-CRUST ; FLAKE TECTONICS ; EASTERN CHINA ; THRUST BELTS ; SULU OROGEN ; U-PB ; COLLISION |
WOS研究方向 | Science & Technology - Other Topics |
语种 | 英语 |
WOS记录号 | WOS:000239619800013 |
出版者 | SCIENCE CHINA PRESS |
源URL | [http://ir.iggcas.ac.cn/handle/132A11/67102] ![]() |
专题 | 中国科学院地质与地球物理研究所 |
通讯作者 | Gao Tianshan |
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.Anhui Survey Reg Geol, Hefei 230001, Peoples R China 3.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China 4.Anhui Inst Geol Survey, Hefei 230001, Peoples R China |
推荐引用方式 GB/T 7714 | Gao Tianshan,Tang Jiafu,Sang Haiqing,et al. Whole-rock Ar-Ar dating for low-grade metavolcanics within the Dabie orogen and its geological signiflcance[J]. CHINESE SCIENCE BULLETIN,2006,51(12):1494-1500. |
APA | Gao Tianshan,Tang Jiafu,Sang Haiqing,Hu Shiling,&Qian Cunchao.(2006).Whole-rock Ar-Ar dating for low-grade metavolcanics within the Dabie orogen and its geological signiflcance.CHINESE SCIENCE BULLETIN,51(12),1494-1500. |
MLA | Gao Tianshan,et al."Whole-rock Ar-Ar dating for low-grade metavolcanics within the Dabie orogen and its geological signiflcance".CHINESE SCIENCE BULLETIN 51.12(2006):1494-1500. |
入库方式: OAI收割
来源:地质与地球物理研究所
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