Evidence for decoupling within subducting continental crust.
文献类型：期刊论文
| 作者 | Dong Feng; Li ShuGuang; Li QiuLi; Liu YiCan; Chen FuKun |
| 刊名 | ACTA PETROLOGICA SINICA
 |
| 出版日期 | 2006-07-01 |
| 卷号 | 22期号:7页码:1791-1798 |
| 关键词 | Chinese Continental Scientific Drilling Project (Ccsd) Uhp Metamorphic Rocks Common Lead Dabie-sulu |
| ISSN号 | 1000-0569 |
| 文献子类 | Article |
| 英文摘要 | This paper reports common Pb isotope data of omphacite in eclogite and feldspar in gneiss from the Chinese Continental Scientific Drilling (CCSD) ( 100 similar to 2000m). The radiogenic Pb of samples from the upper section (0 similar to 800m in drilling core is moderately high with small variations (Pb-206/Pb-204 = 16. 81 similar to 17. 29, (207) Pb/Pb-204 = 15. 37 similar to 15. 45, (208) Pb/Pb-204 = 37.20 similar to 37.66), indicating either high U/Pb and Th/Pb or high initial Pb isotope ratios of their protoliths. The radiogenic Pb of samples from the middle section (800 similar to 1600m) in the drilling core, where ductile shear zones are developed, begins to drop with larger variations (Pb-206/Pb-204 = 16. 26 similar to 16. 72, Pb-207/Pb-204 = 15. 27 similar to 15. 38, Pb-208/Pb-204 = 36. 73 similar to 37. 40). The radiogenic Pb of samples from the lower section ( 1600 similar to 2000m) is moderately low with small variations (Pb-206/Pb-204 = 16. 05 similar to 16. 46, Pb-207/Pb-204 = 15. 22 - 15. 29 Pb-208/Pb-204 = 36. 68 similar to 37. 48) indicating either low U/Pb and Th/Pb or low initial Pb isotope ratios of their protoliths. Comparison between the observed Pb isotopic data and modeling of Pb isotope evolution suggests that the common Pb difference between the upper and lower sections of the drilling core partly inherited from the initial Pb isotope difference between their protoliths, and partly caused by difference p, values of their protoliths. Combined with oxygen isotope data, we interpret the upper and lower sections are two different slabs derived from subducting upper curst and middle crust, respectively. The former is the decoupled upper crust from the subducting continental lithosphere. The detachment between the upper slab and subducting continental lithosphere might have occurred during the continental subduction time, and then the upper slab was uplifted to a shallow depth along the detachment surface by thrust. The lower slab may be a decoupled middle crust, which was detached from the subducting continental lithosphere latterly and was uplifted to a shallower depth below the upper slab. The lowest delta O-18 value (Xiao et al., 2006) in ductile shear zones of the middle section (800 - 1600m) suggests that the detachment surface might have developed along an ancient fault zone, which was a channel of cold meteoric water activity in late Proterozoic. |
| WOS关键词 | ZIRCON U-PB ; O-18 DEPLETION ; EASTERN CHINA ; ECLOGITE ; SULU ; ORTHOGNEISS ; EXHUMATION ; TERRANE ; OXYGEN ; ROCKS |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000245957000004 |
| 出版者 | SCIENCE CHINA PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/66018]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Dong Feng |
| 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, Lab Radiogen Isotope Geochem, Beijing 100029, Peoples R China |
| 推荐引用方式 GB/T 7714 | Dong Feng,Li ShuGuang,Li QiuLi,et al. Evidence for decoupling within subducting continental crust.[J]. ACTA PETROLOGICA SINICA,2006,22(7):1791-1798. |
| APA | Dong Feng,Li ShuGuang,Li QiuLi,Liu YiCan,&Chen FuKun.(2006).Evidence for decoupling within subducting continental crust..ACTA PETROLOGICA SINICA,22(7),1791-1798. |
| MLA | Dong Feng,et al."Evidence for decoupling within subducting continental crust.".ACTA PETROLOGICA SINICA 22.7(2006):1791-1798. |
入库方式： OAI收割
来源：地质与地球物理研究所
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