Experimental investigations of melting and phase relations in the Earth’s core

The Earth’s core is an iron rich alloy, having a minor light element component whose composition remains uncertain. Identifying this light element component is important to understanding the chemical evolution of the Earth, as well as core dynamics, generation of the magnetic field, and mantle-core interaction. I will present recent experimental work on melting and other phase relations in iron-rich systems at high pressures and temperatures, with application to the core. Laser heated diamond anvil cell methods are used to generate the high-P,T conditions, and synchrotron X-ray diffraction and/or optical methods are used to determine melting points and other phase boundaries. The decades-old problem of the core’s composition has not been solved, but these and other recent experimental developments offer important tests of candidate core compositions.