Platinum solubility in silicate melts: The effects of sulfur (S2-), temperature, and melt composition
文献类型：期刊论文
| 作者 | Wang, Wanying1,2,3; Li, Yuan1,2
|
| 刊名 | GEOCHIMICA ET COSMOCHIMICA ACTA
 |
| 出版日期 | 2023-11-15 |
| 卷号 | 361页码:113-132 |
| 关键词 | Platinum solubility Silicate melt Sulfur Partition coefficient Magmas Core formation |
| ISSN号 | 0016-7037 |
| DOI | 10.1016/j.gca.2023.10.016 |
| 英文摘要 | Platinum (Pt) solubility in silicate melt (Sol(Pt)(Sil)) has been determined to understand its behavior in planetary magmas. However, the effect of sulfur (S) in the silicate melt on Sol(Pt)(Sil) was paid little attention. Here we present experiments performed at 1-1.5 GPa, 1300-1700 degrees C, and oxygen fugacity (fO(2)) from IW-1.6 to IW+2.3 (IW denotes the iron-w & uuml;stite buffer) to determine Sol(Pt)(Sil) for silicate melts with major element compositions corresponding to those of rhyolite, mid-ocean ridge basalt, high-FeO basalt, and Martian basalt. The results show that Sol(Pt)(Sil) increases from similar to 0.1 to 10 mu g/g as the S content in silicate melt increases from nominally zero to similar to 4000 mu g/g, which indicates that Pt dissolves predominantly as Pt-sulfide species in S2--bearing silicate melt. Our results also show that Sol(Pt)(Sil) increases with increasing temperature and/or the silicate melt NBO/T (the ratio of non-bridging oxygens to tetrahedrally coordinated cations). Using our newly obtained Sol(Pt)(Sil) and previous data, we developed an empirical model that describes Sol(Pt)(Sil) as a multi-function of temperature, fO(2), the silicate melt NBO/T, and the S2- content in silicate melt in the case at reducing conditions (fO(2) < IW+3.5). The application of our empirical model to mantle partial melting suggests that Pt-rich alloys form only after sulfide liquid exhaustion because of the S-enhanced Sol(Pt)(Sil). We also applied our empirical model to predict the behavior of Pt during arc magmatic differentiation. The results agree with the observations that Pt-rich alloys formed before the saturation of sulfides in the oxidized Pual Ridge lavas. We suggest that the observed coexistence of Pt-bearing alloys and sulfide globules in oxidized arc magmas can be explained by an early formation of Pt-bearing alloys followed by a late formation of sulfide liquids. The strong effect of S2- on Sol(Pt)(Sil) also implies that the oxidization of magmatic melts can lead to direct precipitation of Pt-bearing alloys due to the S2- to S6+ transformation, which can also be subsequently entrapped in the sulfide liquids formed later. Finally, our results show a strong effect of S2- in the silicate melt on lowering the metal-silicate melt partition coefficients of Pt, which should be considered when using Pt to trace planetary accretion and differentiation processes. Collectively, our study demonstrates an important role for S2- in controlling the behavior of Pt during planetary core-mantle-crust differentiation. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001101340700001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/79066]  |
| 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, State Key Lab Isotope Geochem, Guangzhou Inst 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 | Wang, Wanying,Li, Yuan. Platinum solubility in silicate melts: The effects of sulfur (S2-), temperature, and melt composition[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2023,361:113-132. |
| APA | Wang, Wanying,&Li, Yuan.(2023).Platinum solubility in silicate melts: The effects of sulfur (S2-), temperature, and melt composition.GEOCHIMICA ET COSMOCHIMICA ACTA,361,113-132. |
| MLA | Wang, Wanying,et al."Platinum solubility in silicate melts: The effects of sulfur (S2-), temperature, and melt composition".GEOCHIMICA ET COSMOCHIMICA ACTA 361(2023):113-132. |
入库方式： OAI收割
来源：广州地球化学研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。