Experimental constraints on the behavior of Pt and Re in oxidized arc magmas
文献类型：期刊论文
| 作者 | Liu, Zhiwei1,2,3; Li, Yuan1,2
|
| 刊名 | EARTH AND PLANETARY SCIENCE LETTERS
 |
| 出版日期 | 2023-02-01 |
| 卷号 | 603页码:14 |
| 关键词 | rhenium platinum sulfides magnetite partition coefficients arc magmas |
| ISSN号 | 0012-821X |
| DOI | 10.1016/j.epsl.2022.117986 |
| 英文摘要 | Highly siderophile elements such as Pt and Re are important tracers for Earth's crust-mantle differen-tiation. The behavior of Pt and Re in oxidized arc magmas are thought to be controlled by their strong partitioning into sulfides and/or magnetite. Disequilibrium fractionation of sulfide liquid was proposed to explain the Pt systematics in magmas when using sulfide liquid-silicate melt partition coefficients of Pt (DSul/Sil Pt ) of 105. However, the segregating sulfides are coexisting monosulfide-solid-solution (MSS) and Cu-rich sulfide liquid in thin island arcs, but mainly as MSS in thick continental arcs. Here we exper-imentally determine the MSS-silicate melt partition coefficients of Pt (DMSS/Sil Pt) and magnetite-silicate melt partition coefficients of Re (DMag/Sil Re ) at 0.4-0.5 GPa, 1020-1100 degrees C, and oxygen fugacity ( f O2) from below FMQ-1.7 to-FMQ+2.5, using a piston cylinder apparatus. The results show that DMSS/Sil range Pt between 20-8700 and increase with increasing Pt concentration (20-530 mu g/g) in MSS at a given fO2, which can be explained by the presence of Pt-rich nuggets in MSS and the non-Henrian law behavior of DMSS/Sil Pt . This finding suggests that Pt in oxidized arc magmas is much less chalcophile than previously thought. The obtained DMag/Sil Re increase from 0.5 to 2.9 with fO2 decreasing from-FMQ+2.5 to FMQ+1, suggesting that Re is incompatible to slightly compatible in magnetite in oxidized arc magmas. Re dis-solves as Re4+ in magnetite through the substitution of Re4+ + Fe2+ for 2Fe3+. The application of our new Ds together with previous Ds to a magmatic differentiation model, which involves an equilibrium fractionation of MSS and/or sulfide liquid, magnetite, and silicate minerals, can fully reproduce the evo-lution trends of Pt, Re, and Cu in oxidized, sulfide-saturated arc magmas. Our model results demonstrate that equilibrium fractionation of sulfides predominantly controls the behavior of Pt and Re in oxidized arc magmas with sulfide saturation.(c) 2023 Elsevier B.V. All rights reserved. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000920947300001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/72446]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 通讯作者 | Li, Yuan |
| 作者单位 | 1.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China 2.CAS Ctr Excellence Deep Earth Sci, Guangzhou 510640, Peoples R China 3.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing 100049, Peoples R China |
| 推荐引用方式 GB/T 7714 | Liu, Zhiwei,Li, Yuan. Experimental constraints on the behavior of Pt and Re in oxidized arc magmas[J]. EARTH AND PLANETARY SCIENCE LETTERS,2023,603:14. |
| APA | Liu, Zhiwei,&Li, Yuan.(2023).Experimental constraints on the behavior of Pt and Re in oxidized arc magmas.EARTH AND PLANETARY SCIENCE LETTERS,603,14. |
| MLA | Liu, Zhiwei,et al."Experimental constraints on the behavior of Pt and Re in oxidized arc magmas".EARTH AND PLANETARY SCIENCE LETTERS 603(2023):14. |
入库方式： OAI收割
来源：广州地球化学研究所
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