| Geochronology and geochemistry of the Early Jurassic Yeba Formation volcanic rocks in southern Tibet: Initiation of back-arc rifting and crustal accretion in the southern Lhasa Terrane | |
| Wei, Youqing1,2; Zhao, Zhidan1,2; Niu, Yaoling3,4; Zhu, Di-Cheng1,2; Liu, Dong1,2; Wang, Qing1,2; Hou, Zengqian5; Mo, Xuanxue1,2; Wei, Jiuchuan6 | |
| 2017-05-01 | |
| 发表期刊 | LITHOS
 |
| 卷号 | 278页码:477-490 |
| 文章类型 | Article |
| 摘要 | Understanding the geological history of the Lhasa Terrane prior to the India-Asia collision (similar to 55 +/- 10 Ma) is essential for improved models of syn-collisional and post-collisional processes in the southern Lhasa Terrane. The Miocene (similar to 18-10 Ma) adakitic magmatism with economically significant porphyry-type mineralization has been interpreted as resulting from partial melting of the Jurassic juvenile crust, but how this juvenile crust was accreted remains poorly known. For this reason, we carried out a detailed study on the volcanic rocks of the Yeba Formation (YF) with the results offering insights into the ways in which the juvenile crust may be accreted in the southern Lhasa Terrane in the Jurassic. The YF volcanic rocks are compositionally bimodal, comprising basalt/basaltic andesite and dacite/rhyolite dated at 183-174 Ma. All these rocks have an arc-like signature with enriched large ion lithophile elements (LILEs; e.g., Rb, Ba and U) and light rare earth elements (LREEs) and depleted high field strength elements (HFSEs; e.g., Nb, Ta, Ti). They also have depleted whole-rock Sr-Nd and zircon Hf isotopic compositions, pointing to significant mantle isotopic contributions. Modeling results of trace elements and isotopes are most consistent with the basalts being derived from a mantle source metasomatized by varying enrichment of subduction components. The silicic volcanic rocks show the characteristics of transitional I-S type granites, and are best interpreted as resulting from re-melting of a mixed source of juvenile amphibole-rich lower crust with reworked crustal materials resembling metagraywackes. Importantly, our results indicate northward Neo-Tethyan seafloor subduction beneath the Lhasa Terrane with the YF volcanism being caused by the initiation of back-arc rifting. The back-arc setting is a likely site for juvenile crustal accretion in the southern Lhasa Terrane. (C) 2017 Elsevier B.V. All rights reserved. |
| 关键词 | Geochemistry Geochronology Sr-nd-hf Isotopes Back-arc Yeba Formation Crustal Accretion |
| DOI | 10.1016/j.lithos.2017.02.013 |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000399258500032 |
| 引用统计 | |
| 文献类型 | 期刊论文 |
| 版本 | 出版稿 |
| 条目标识符 | http://ir.qdio.ac.cn/handle/337002/137058 |
| 专题 | 海洋地质与环境重点实验室 |
| 作者单位 | 1.China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Beijing 100083, Peoples R China 2.China Univ Geosci, Sch Earth Sci & Resources, Beijing 100083, Peoples R China 3.Chinese Acad Sci, Inst Oceanol, Qingdao 266071, Peoples R China 4.Univ Durham, Dept Earth Sci, Durham DH1 3LE, England 5.Chinese Acad Geol Sci, Inst Geol, Key Lab Continental Tecton & Dynam, Beijing 100037, Peoples R China 6.Shandong Univ Sci & Technol, Coll Earth Sci & Technol, Qingdao 266590, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wei, Youqing,Zhao, Zhidan,Niu, Yaoling,et al. Geochronology and geochemistry of the Early Jurassic Yeba Formation volcanic rocks in southern Tibet: Initiation of back-arc rifting and crustal accretion in the southern Lhasa Terrane[J]. LITHOS,2017,278:477-490. |
| APA | Wei, Youqing.,Zhao, Zhidan.,Niu, Yaoling.,Zhu, Di-Cheng.,Liu, Dong.,...&Wei, Jiuchuan.(2017).Geochronology and geochemistry of the Early Jurassic Yeba Formation volcanic rocks in southern Tibet: Initiation of back-arc rifting and crustal accretion in the southern Lhasa Terrane.LITHOS,278,477-490. |
| MLA | Wei, Youqing,et al."Geochronology and geochemistry of the Early Jurassic Yeba Formation volcanic rocks in southern Tibet: Initiation of back-arc rifting and crustal accretion in the southern Lhasa Terrane".LITHOS 278(2017):477-490. |
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| Geochronology and ge（2266KB） | 期刊论文 | 出版稿 | 限制开放 | CC BY-NC-SA | 浏览 | |
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