Crust-Mantle Interaction in a Continental Subduction Channel: Evidence from Orogenic Peridotites in North Qaidam, Northern Tibet
文献类型：期刊论文
| 作者 | Chen, Ren-Xu1; Li, Hai-Yong1; Zheng, Yong-Fei1; Zhang, Long1; Gong, Bing1; Hu, Zhaochu2; Yang, Yueheng3 |
| 刊名 | JOURNAL OF PETROLOGY
 |
| 出版日期 | 2017-02-01 |
| 卷号 | 58期号:2页码:191-226 |
| 关键词 | continental collision subduction zone metamorphic geochemistry slab-mantle interaction orogenic peridotite garnet pyroxenite metasomatic zircon |
| ISSN号 | 0022-3530 |
| DOI | 10.1093/petrology/egx011 |
| 文献子类 | Article |
| 英文摘要 | A combined study of rock-forming mineral and O isotope compositions, zircon U-Pb ages, trace element compositions, mineral inclusions and Hf-O isotopes was made on orogenic peridotites from North Qaidam in northern Tibet to provide insights into crustal metasomatism at the slab-mantle interface in a continental subduction channel. Rock-forming mineral O isotope analyses yield olivine delta O-18 values of 5.0-5.6 parts per thousand for lherzolites and 3.5-5.3 parts per thousand for dunites; orthopyroxene has delta O-18 values of 4.5-5.3 parts per thousand for lherzolites, 4.5-5.3 parts per thousand for dunites, and 7.8 parts per thousand for pyroxenites. It appears that the protolith of these ultramafic rocks underwent high-temperature metasomatism by both low-and high-delta O-18 fluids. The occurrence of zircon in thin section and the presence of olivine inclusions in zircon from these rocks explicitly indicates the growth of metasomatic zircon during continental subduction zone processes. Two distinct groups of zircon domains are distinguished. Intermediate-to high-luminescent zircon domains have U-Pb ages of 417 +/- 4 to 426 +/- 3Ma, variable Th/U ratios, low rare earth element (REE) contents, flat heavy REE (HREE) patterns with a relative lack of negative Eu anomalies, and inclusions of olivine, clinopyroxene, orthopyroxene and graphite. These features are interpreted as zircon growth through metasomatic reaction by addition of fluids in the early exhumation stage of deeply subducted continental crust. The Hf-O isotope compositions of these zircon domains suggest the same origin for these fluids. In contrast, low-luminescent zircon rims mostly exhibit younger U-Pb ages of 404 +/- 3 to 405 +/- 8Ma, low Th/U ratios <0.1, high REE contents, and steep HREE patterns with negative Eu anomalies, and contain calcite inclusions as well as multiphase solid inclusions of Cal+Kfs and Qtz+Kfs+Pl. Such observations indicate their growth through metasomatic reaction by infiltration of hydrous silicate melts during the late exhumation stage. All the zircon domains have variable Hf isotope compositions with a large difference between samples, but a narrow delta O-18 range from 5.4 to 6.6 parts per thousand. Their Hf-O isotope compositions are similar to those of UHP metamorphic rocks in North Qaidam, suggesting that the metasomatic fluids originated from deeply subducted continental crust. Whereas the high-delta O-18 fluids originated from deeply subducted continental crust, the low-delta O-18 fluids were derived from dehydration of the subducting oceanic crust that preceded the subduction of continental crust. The orogenic peridotites thus record the metasomatic reaction of mantle wedge peridotite with fluids of different origins. |
| WOS关键词 | OXYGEN-ISOTOPE FRACTIONATION ; PRESSURE METAMORPHIC ROCKS ; U-PB AGES ; MULTIPHASE SOLID INCLUSIONS ; WESTERN GNEISS REGION ; SULU UHP TERRANE ; IN-SITU ANALYSIS ; LU-HF ISOTOPE ; LA-ICP-MS ; GARNET-PERIDOTITE |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000404122800001 |
| 出版者 | OXFORD UNIV PRESS |
| 资助机构 | Chinese Ministry of Science and Technology(2015CB856106) ; Natural Science Foundation of China(41590620 ; Youth Innovation Promotion Association CAS(2013283) ; Fundamental Research Funds for the Central Universities(WK 3410000009) ; Foundation for the Author of National Excellent Doctoral Dissertation of PR China(201229) ; 41422301 ; 41372073) ; Chinese Ministry of Science and Technology(2015CB856106) ; Natural Science Foundation of China(41590620 ; Youth Innovation Promotion Association CAS(2013283) ; Fundamental Research Funds for the Central Universities(WK 3410000009) ; Foundation for the Author of National Excellent Doctoral Dissertation of PR China(201229) ; 41422301 ; 41372073) ; Chinese Ministry of Science and Technology(2015CB856106) ; Natural Science Foundation of China(41590620 ; Youth Innovation Promotion Association CAS(2013283) ; Fundamental Research Funds for the Central Universities(WK 3410000009) ; Foundation for the Author of National Excellent Doctoral Dissertation of PR China(201229) ; 41422301 ; 41372073) ; Chinese Ministry of Science and Technology(2015CB856106) ; Natural Science Foundation of China(41590620 ; Youth Innovation Promotion Association CAS(2013283) ; Fundamental Research Funds for the Central Universities(WK 3410000009) ; Foundation for the Author of National Excellent Doctoral Dissertation of PR China(201229) ; 41422301 ; 41372073) |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/51795]  |
| 专题 | 地质与地球物理研究所_岩石圈演化国家重点实验室 |
| 通讯作者 | Chen, Ren-Xu |
| 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.China Univ Geosci, State Key Lab Geol Proc & Mat Resources, Fac Earth Sci, Wuhan 430074, Peoples R China 3.Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China |
| 推荐引用方式 GB/T 7714 | Chen, Ren-Xu,Li, Hai-Yong,Zheng, Yong-Fei,et al. Crust-Mantle Interaction in a Continental Subduction Channel: Evidence from Orogenic Peridotites in North Qaidam, Northern Tibet[J]. JOURNAL OF PETROLOGY,2017,58(2):191-226. |
| APA | Chen, Ren-Xu.,Li, Hai-Yong.,Zheng, Yong-Fei.,Zhang, Long.,Gong, Bing.,...&Yang, Yueheng.(2017).Crust-Mantle Interaction in a Continental Subduction Channel: Evidence from Orogenic Peridotites in North Qaidam, Northern Tibet.JOURNAL OF PETROLOGY,58(2),191-226. |
| MLA | Chen, Ren-Xu,et al."Crust-Mantle Interaction in a Continental Subduction Channel: Evidence from Orogenic Peridotites in North Qaidam, Northern Tibet".JOURNAL OF PETROLOGY 58.2(2017):191-226. |
入库方式： OAI收割
来源：地质与地球物理研究所
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