Dissolution of Silicon and Oxygen in Molten Iron at High Pressure and Temperature

Abstract

Reaction between molten iron and silicate at high pressure and temperature was examined by employing a mixture of pure iron and (Mg_0.9Fe_0.1)₂SiO₄ olivine as the starting material. The experimental charge quenched at 24 GPa and 2550°C demonstrated that certain amount of SiO₂ component (at least 2wt% of Si) dissolved into mol ten iron fromthe silicate melt. It is suggested that the dissolving would be enhanced with increasing pressure. The experimental results indicate that Si and O are the important alloying light-elements in the earth's core if the core segregation proceeded in the magma ocean of the proto-earth. Concurrently, SiO₂ contents of the mantle should be substantially reduced from its primitive content.