New techniques and combinations of existing techniques will be used in our studies of the properties of mantle and core materials. The research will consist of two general areas of high pressure/temperature research: 1) the measurement of strength of mantle materials at high pressures and temperatures using diamond anvil cells and synchrotron radiation, 2) study of phase transitions and melting in MgSiO3, MgO and iron at very high pressures and temperatures by laser heating and synchrotron radiation. Our understanding of the dynamics of the mantle and especially the origin of deep earthquakes depends on our knowledge of the mechanisms and kinetics of phase transitions and the strength of various phases at the pressure/temperature conditions of the Earth's mantle. Our understanding of the temperature distribution and composition of the mantle and core depends on our knowledge of the melting temperatures of important mantle and core materials.