Iron isotope fractionation during mid-ocean ridge basalt (MORB) evolution: Evidence from lavas on the East Pacific Rise at 10 degrees 30 ' N and its implications
文献类型：期刊论文
| 作者 | Chen, Shuo3,4,5; Niu, Yaoling1,2,4; Guo, Pengyuan3,4,5; Gong, Hongmei3,4,5; Sun, Pu3,4,5 ; Xue, Qiqi5; Duan, Meng3,4,5; Wang, Xiaohong3,4,5
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| 刊名 | GEOCHIMICA ET COSMOCHIMICA ACTA
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| 出版日期 | 2019-12-15 |
| 卷号 | 267页码:227-239 |
| ISSN号 | 0016-7037 |
| 关键词 | Fe isotope Mid-ocean ridge basalts East Pacific Rise Bulk silicate earth |
| DOI | 10.1016/j.gca.2019.09.031 |
| 英文摘要 | Whether the Earth's mantle has a chondritic delta Fe-56 (deviation in Fe-56/Fe-54 from the IRMM-014 standard in parts per thousand) value or not remains under debate. The current view is that the observed average delta Fe-56 of mid-ocean ridge basalts (MORB) cannot be explained by partial melting of mantle source with chondritic value alone. Here, we report Fe isotope compositions on 29 MORB glasses sampled along a flowline traverse across the East Pacific Rise (EPR) axis at 10 degrees 30'N. These glasses show large MgO variation (1.8-7.4 wt.%) that forms a compositional continuum resulting from varying extent of fractional crystallization, which is accompanied by systematic Fe isotopic variation. Fractional crystallization modeling suggests that early crystallization of olivine, pyroxene and plagioclase gives rise to an iron enrichment trend and an increase in delta Fe-56. Once Fe-Ti oxides appear on the liquidus and begin to crystallize, the FeOt and TiO2 contents of the residual melt decrease rapidly, which lead to a slight decrease in delta Fe-56. These observations indicate that significant Fe isotope fractionation can indeed take place during MORB melt evolution. Hence, delta Fe-56 values of variably evolved MORB melts do not represent those of primary MORB melts and thus cannot be used to infer mantle source Fe isotope compositions. Importantly, delta Fe-56 values of primary MORB melts after correction for the effect of fractional crystallization can be well reproduced by mantle melting. Therefore, our study supports the idea that the Fe isotope composition of the accessible Earth is close to be chondritic. We note that conclusion would assume that the core, which takes up similar to 90% of the Earth's Fe, must have a chondritic Fe isotope composition. (C) 2019 Elsevier Ltd. All rights reserved. |
| 资助项目 | National Natural Science Foundation (NSFC)-Shandong Joint Fund for Marine Science Research Centers[U1606401] ; China Postdoctoral Science Foundation[2019M652496] ; NSFC[41630968] ; NSFC[41776067] ; NSFC[41130314] ; 111 project[B18048] |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| 出版者 | PERGAMON-ELSEVIER SCIENCE LTD |
| WOS记录号 | WOS:000491872600013 |
| 版本 | 出版稿 |
| 源URL | [http://ir.qdio.ac.cn/handle/337002/165031]  |
| 专题 | 中国科学院海洋研究所 |
| 通讯作者 | Chen, Shuo; Niu, Yaoling |
| 作者单位 | 1.China Univ Geosci, Beijing 100083, Peoples R China 2.Univ Durham, Dept Earth Sci, Durham DH1 3LE, England 3.Chinese Acad Sci, Ctr Ocean Megasci, 7 Nanhai Rd, Qingdao 266071, Shandong, Peoples R China 4.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Geol, Qingdao 266061, Shandong, Peoples R China 5.Chinese Acad Sci, Inst Oceanol, Qingdao 266071, Shandong, Peoples R China |
| 推荐引用方式 GB/T 7714 | Chen, Shuo,Niu, Yaoling,Guo, Pengyuan,et al. Iron isotope fractionation during mid-ocean ridge basalt (MORB) evolution: Evidence from lavas on the East Pacific Rise at 10 degrees 30 ' N and its implications[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2019,267:227-239. |
| APA | Chen, Shuo.,Niu, Yaoling.,Guo, Pengyuan.,Gong, Hongmei.,Sun, Pu.,...&Wang, Xiaohong.(2019).Iron isotope fractionation during mid-ocean ridge basalt (MORB) evolution: Evidence from lavas on the East Pacific Rise at 10 degrees 30 ' N and its implications.GEOCHIMICA ET COSMOCHIMICA ACTA,267,227-239. |
| MLA | Chen, Shuo,et al."Iron isotope fractionation during mid-ocean ridge basalt (MORB) evolution: Evidence from lavas on the East Pacific Rise at 10 degrees 30 ' N and its implications".GEOCHIMICA ET COSMOCHIMICA ACTA 267(2019):227-239. |
入库方式： OAI收割
来源：海洋研究所
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