Oxygen solubility in Fe-Ni-S alloy at high pressure and implications for the formation and compositions of planetary cores

• Antragsteller: Professor Dr. Falko Langenhorst; Professor Dr. David Rubie
• Fachliche Zuordnung: Mineralogie, Petrologie und Geochemie
• Förderung: Förderung von 2005 bis 2010
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 18244188

The most important fractionation event to affect the geochemistry of the terrestrial planets was their segregation into metallic Fe-rich cores and silicate mantles. Although this process clearly influenced the distribution of siderophile elements between these regions, the conditions under which it took place and the resulting distribution of light elements remain poorly constrained. In the course of this study we aim to develop new models for the geochemical evolution of terrestrial planets during core formation. The solubility of oxygen and sulphur in Fe and Fe-Ni-rich liquid metal will be studied in experiments to pressures of up 25 GPa. Using a thermodynamic model fit to the results of these experiments the geochemical consequences of metal silicate equilibration in realistic magma ocean environments will be explored, partly in collaboration with Prof. U. Hansen/Münster. These models will enable us to understand, for example, whether the core formed progressively as a result of a series of relatively shallow magma oceans during accretion or whether core-mantle equilibration was partly or completely established during melting of the entire mantle.

• DFG-Verfahren: Schwerpunktprogramme
• Teilprojekt zu: SPP 1115: Mars und die terrestrischen Planeten
• Beteiligte Person: Professor Dr. Daniel J. Frost