MIT Experimental Petrology Laboratory

CORE FORMATION

There are few constraints on the early processes that led to the formation of the cores of the terrestrial planets.

Our approach is to pursue experiments that illuminate the effects of variations in sulfur fugacity and oxidation state recorded in the silicates that were subjected to a core-forming event.

This indirect approach allows compositional variations preserved in mantle minerals to be used to track a core-forming event, and to see if the conditions of core formation can be inferred.

The variations in partial pressures of sulfur and oxygen species in a planetary interior exercise key controls on the abundances of siderophile elements that partition between the silicate portion of a planet's interior and the metal portion that segregates to form the core.

Current experimental projects involve core formation on the Eucrite Parent body (4-Vesta) are exploring the apparent consensus that core formation occurred at low melt fractions.

In the Earth's mantle the high siderophile element abundances are inconsistent with any simple core-forming processes and understanding this paradox remains a continuing challenge.