9725453 Duffy This grant provides partial support of the costs of acquiring a Brillouin spectroscopy system for direct measurement of the single-crystal elastic moduli of minerals in diamond anvil cells (DAC) at upper to lower mantle pressures and temperatures. These measurements are fundamental to interpretation of the composition, thermal structure and rheology of the Earth's mantle. Additionally, mineral elasticity data are fundamental to problems in mineral physics including understanding the phenomenon of pressure induced amorphization and development of an absolute pressure scale for high pressure experimentation. The proposed facility will generated new data on the elastic properties of minerals and mineral assemblages at pressure ranges that span an important transition zone in the uppermost lower mantle of the Earth and which are fundamental to our understanding of mantle dynamics and to interpretation of seismic data. ***
