Experimental Constraints on Physical Mechanisms of Core Formation

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Understanding both the chemical and physical processes that contribute to the early differentiation of planets into rocky (silicate) mantles and metallic cores is fundamental to the understanding of Earth's evolution. It has been proposed that the early Earth experienced wide spread melting, and the resulting metallic liquid segregated from the remaining silicate material at high pressures and temperatures forming the core. A comprehensive framework for core formation mechanisms in a partially molten silicate at the grain scale has not yet been fully established. This project utilizes recently developed experimental methods and imaging techniques coupled with numerical simulations to determine the physical processes that allow for segregation of metallic liquids from partially molten silicates at conditions relevant to the differentiation of the planet Earth.This work will address the rate(s) of metal segregation for several equilibrium and non-equilibrium core formation scenarios at the grain scale. Specifically, the effect varying degrees of partially molten silicate melt, different compositions of metallic melt and the influence of sustained deformation on the distribution and mobility of metallic melts will be quantified. The combined approach of experimental measurement and numerical simulation adds a new way of quantifying the three dimensional geometry and grain scale mobility of core forming melts that has not been available through traditional estimates of permeability and migration velocity.