Contrasting Cu isotopes in mid-ocean ridge basalts and lower oceanic crust: Insights into the oceanic crustal magma plumbing systems
文献类型：期刊论文
| 作者 | Zou, Zongqi1,7; Wang, Zaicong1,6; Xu, Yi-Gang2,7; Ciazela, Jakub3; Wang, Xia1; Foley, Stephen4; Zhang, Wei-Qi5; Li, Wei5; Li, Ming1; Liu, Yongsheng1 |
| 刊名 | EARTH AND PLANETARY SCIENCE LETTERS
 |
| 出版日期 | 2024-02-01 |
| 卷号 | 627页码:13 |
| 关键词 | Cu isotope MORBs Gabbro Sulfide Plumbing systems |
| ISSN号 | 0012-821X |
| DOI | 10.1016/j.epsl.2023.118563 |
| 英文摘要 | Magma plumbing systems exert strong controls on the formation and evolution of the oceanic crust during crust accretion. However, plumbing system dynamics based largely on mid-ocean ridge basalts (MORBs) are extremely difficult to constrain because the MORBs are aggregated melts and original information may have been blurred. Copper isotopic compositions of lower crustal gabbroic cumulates effectively archive early-stage histories because sulfides constitute the dominant Cu budget of gabbroic cumulates and are largely isolated from subsequent magma filtering processes. Here, we present Cu isotopes of a suite of gabbroic cumulates from the ultraslow-spreading Southwest Indian Ridge (Hole U1473A), and MORBs from the South Mid-Atlantic Ridge and East Pacific Rise. The delta 65Cu of the MORBs from this study (+0.04 %o to +0.19 %o) match those of previous MORB analyses, indicating uniform delta 65Cu at various spreading rates. In contrast, the delta 65Cu of gabbroic rocks vary significantly (-1.14 %o to 0.87 %o), exceeding by far the range known for peridotites. The Cu budget of these gabbroic rocks is hosted in sulfides and the mantle-like S isotopic compositions of sulfides indicate their origin of igneous processes. These results thus suggest that magma accumulation and sulfide segregation would lead to notable Cu isotopic fractionation in the lower oceanic crust. We propose that repeated recharging of primitive melts and efficient mixing of melts within the plumbing system can buffer the removal of early 63Cu-rich sulfides from sulfide-saturated MORBs. The discrepancy in delta 65Cu between lower oceanic crust and MORBs is a natural consequence of continuous replenishment that occurs concurrently with melt-rock interaction, mixing, crystallization and extraction, irrespective of the oceanic settings. The consistent delta 65Cu in MORBs (0.09 +/- 0.08 %o) and komatiites (0.06 +/- 0.06 %o) further indicates that their Cu isotopes reflect the mean mantle source composition, providing a robust delta 65Cu for bulk silicate Earth (BSE) of 0.08 +/- 0.08 %o (2sd). Accordingly, we propose that in open sub-ridge plumbing systems, other incompatible element isotopes and ratios of elements with similar incompatibility in MORBs as Cu isotopes suggest, could also represent mean mantle source compositions. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001154776600001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/76200]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 通讯作者 | Wang, Zaicong |
| 作者单位 | 1.China Univ Geosci, Sch Earth Sci, State Key Lab Geol Proc & Mineral Resources, Wuhan 430074, Peoples R China 2.Southern Marine Sci & Engn Guangdong Lab Guangzhou, Guangzhou 511458, Peoples R China 3.Polish Acad Sci, Inst Geol Sci, Ul Twarda 51-55, PL-00818 Warsaw, Poland 4.Macquarie Univ, Sch Nat Sci, N Ryde, NSW 2109, Australia 5.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 6.Minist Nat Resources, State Ocean Adm, Inst Oceanog 2, Key Lab Submarine Geosci, Hangzhou 310012, Peoples R China 7.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zou, Zongqi,Wang, Zaicong,Xu, Yi-Gang,et al. Contrasting Cu isotopes in mid-ocean ridge basalts and lower oceanic crust: Insights into the oceanic crustal magma plumbing systems[J]. EARTH AND PLANETARY SCIENCE LETTERS,2024,627:13. |
| APA | Zou, Zongqi.,Wang, Zaicong.,Xu, Yi-Gang.,Ciazela, Jakub.,Wang, Xia.,...&Liu, Yongsheng.(2024).Contrasting Cu isotopes in mid-ocean ridge basalts and lower oceanic crust: Insights into the oceanic crustal magma plumbing systems.EARTH AND PLANETARY SCIENCE LETTERS,627,13. |
| MLA | Zou, Zongqi,et al."Contrasting Cu isotopes in mid-ocean ridge basalts and lower oceanic crust: Insights into the oceanic crustal magma plumbing systems".EARTH AND PLANETARY SCIENCE LETTERS 627(2024):13. |
入库方式： OAI收割
来源：广州地球化学研究所
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