DISSOLUTION OF SILICON AND OXYGEN IN MOLTEN IRON AT HIGH-PRESSURE AND TEMPERATURE

Reaction between molten iron and silicate at high pressure and temperature was examined by employing a mixture of pure iron and (Mg0.9Fe0.1)2SiO4 olivine as the starting material. The experimental charge quenched at 24 GPa and 2550-degrees-C demonstrated that Certain amount of SiO2 component (at least 2 wt% of Si) dissolved into molten iron from the 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.