| The origin of Cenozoic basalts from central Inner Mongolia, East China: The consequence of recent mantle metasomatism genetically associated with seismically observed paleo-Pacific slab in the mantle transition zone | |
Guo, Pengyuan1,2; Niu, Yaoling3,4; Sun, Pu3 ; Ye, Lei2; Liu, Jinju2; Zhang, Yu2; Feng, Yue-xing5; Zhao, Jian-xin5
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| 2016 | |
| 发表期刊 | LITHOS
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| 卷号 | 240页码:104-118 |
| 文章类型 | Article |
| 摘要 | We present new major element, trace element and Sr-Nd-Hf isotope data on Cenozoic basalts from central Inner Mongolia (CIM) in eastern China to study the origin of the incompatible-element enriched component in these basalts by testing whether or not the paleo-Pacific plate lying in the mantle transition zone beneath eastern China is the immediate cause. The Cenozoic CIM basalts have a large variation in major element, trace element and isotope compositions. Fractional crystallization of olivine and clinopyroxene can readily explain much of the major element compositional variation, while trace element and isotope ratio variation largely reflect source heterogeneities and source histories. The variably low Sr-87/Sr-86, high epsilon(Nd), high epsilon(Hf) and elevated ratios of high field strength element over large ion lithophile element (HFSE/LILE, e.g., Nb/U, Nb/La) indicate that the CIM basalts are of asthenospheric origin, which is characterized by mixing between DMM and EM1. However, the CIM basalts are enriched in incompatible elements and enriched in the progressively more incompatible elements (e.g., variably high [La/Sm](N) = 1.66-3.38), suggesting that the magma source(s) must have been enriched prior to the major episode of the magmatism. Participation of subducted ocean crust in the mantle source region of these basalts is recognized, but cannot be the major source material because the subducted ocean crust is expectedly too depleted in incompatible elements (e.g., [La/Sm](N) << 1) to produce magmas highly enriched in incompatible elements with [La/Sm](N) >> 1. With the new data, we consider that low mass fraction (low-F) melt metasomatism in the seismic low velocity zone (LVZ) beneath eastern China as the most likely process to generate incompatible-element enriched source(s) for mantle melts parental to the Cenozoic CIM basalts. The low-F meta somatic agent most likely resulted from dehydration melting of the transition-zone paleo-Pacific slab, which has been taking place in the Cenozoic. This recent/current metasomatic process also explains the strong decoupling of the abundances and ratios of incompatible elements (e.g., Rb/Sr, Sm/Nd, Lu/Hf, La/Sm, Sm/Yb) from Sr-Nd-Hf isotopes because of the inadequate time for radiogenic ingrowth. In this case, we emphasize that the Cenozoic volcanism in eastern China (including the CIM basalts) is a special consequence of plate tectonics. |
| 关键词 | Intra-plate Basalts Metasomatism Hydrous Low-f Melt Recycled Ocean Crust Subducted Paleo-pacific Plate |
| DOI | 10.1016/j.lithos.2015.11.010 |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000372383600007 |
| 引用统计 | |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://ir.qdio.ac.cn/handle/337002/126216 |
| 专题 | 海洋地质与环境重点实验室 |
| 作者单位 | 1.Chinese Acad Sci, Inst Deep Sea Sci & Engn, Lizhigou Rd, Sanya 572000, Hainan, Peoples R China 2.Lanzhou Univ, Sch Earth Sci, Lanzhou 730000, 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.Univ Queensland, Sch Earth Sci, Radiogen Isotope Facil, Brisbane, Qld 4072, Australia |
| 推荐引用方式 GB/T 7714 | Guo, Pengyuan,Niu, Yaoling,Sun, Pu,et al. The origin of Cenozoic basalts from central Inner Mongolia, East China: The consequence of recent mantle metasomatism genetically associated with seismically observed paleo-Pacific slab in the mantle transition zone[J]. LITHOS,2016,240:104-118. |
| APA | Guo, Pengyuan.,Niu, Yaoling.,Sun, Pu.,Ye, Lei.,Liu, Jinju.,...&Zhao, Jian-xin.(2016).The origin of Cenozoic basalts from central Inner Mongolia, East China: The consequence of recent mantle metasomatism genetically associated with seismically observed paleo-Pacific slab in the mantle transition zone.LITHOS,240,104-118. |
| MLA | Guo, Pengyuan,et al."The origin of Cenozoic basalts from central Inner Mongolia, East China: The consequence of recent mantle metasomatism genetically associated with seismically observed paleo-Pacific slab in the mantle transition zone".LITHOS 240(2016):104-118. |
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| The origin of Cenozo（1767KB） | 期刊论文 | 出版稿 | 限制开放 | CC BY-NC-SA | 浏览 | |
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