Geocheminar winter-2013

Silicate melts are a major driving force of planetary differentiation and play a large role in the thermal and chemical evolution of the earth. During crystallization of a putative magma ocean and also during partial melting events in predominantly solid mantle environments, the formation of chemically distinct reservoirs controlled by gravitational differentiation is intimately linked to the solid and liquid equations of state (EOS). Hence, a fundamental knowledge of silicate liquid volumes at extreme pressure and temperature conditions is necessary for understanding the evolution of the earth, yet melts are complex materials that can create many challenges to experimental and theoretical prediction of their properties. I will be presenting the results and challenges of constraining liquid EOS using shock wave pre-heated sample techniques. Specific to these results, I will discuss our current understanding of the temperature dependence of sound speed in ultramafic liquids and also explore the question of whether a liquid could be gravitationally stable at the core-mantle boundary.