Immiscible two-liquid regions in the Fe-O-S system at high pressure: Implications for planetary cores |
| |
| Authors: | Kyusei Tsuno Eiji Ohtani Hidenori Terasaki |
| |
| Institution: | Institute of Mineralogy, Petrology, and Economic Geology, Faculty of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan |
| |
| Abstract: | We have determined phase relations in the Fe-O and Fe-O-S systems in the range of 15-21 GPa and 1825-2300 °C. Below the liquidus temperatures, solid FeO and metallic liquids are observed in both the Fe-O and the Fe-O-S systems. An immiscible two-liquid region exists in the Fe-O binary system in the pressure range investigated, and the immiscibility gap between Fe-rich metallic liquid and FeO-rich ionic liquid does not greatly change with either pressure or temperature. On the other hand, an immiscible two-liquid region in the Fe-O-S ternary system narrows significantly with increasing pressure at constant temperature and vice versa, and it almost disappears at 21 GPa, and 2300 °C. Immiscible two-liquid regions are thus not expected to exist in the Fe-O-S system in the Earth's core, suggesting that both oxygen and sulfur can be incorporated into the core. Our results are consistent with a geochemical model for the core containing 5.8 wt.% oxygen and 1.9 wt.% sulfur as proposed by McDonough and Sun McDonough, W.F., Sun, S.-S., 1995. The composition of the Earth. Chem. Geol. 120, 223-253]. |
| |
| Keywords: | Core Fe-alloys Liquid immiscibility Miscibility High pressure |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
