Brown 9418827 The PI will continue studies of the physical properties (principally the elastic constants and thermal diffusivity) of candidate mantle constituents under earth mantle conditions of pressure and temperature. Seismic velocities provide the most highly resolved view of Earth's interior and laboratory calibration at high pressure and temperature is essential in interpretation of seismic models. Acquisition of these data will remove the current ambiguities associated with uncertain extrapolations to high pressure, and thus will provide better constraints on the thermal and compositional state of the mantle. Measurements will be extended to simultaneous high temperature and high pressure and studies of high pressure mantle silicate phases will be initiated. ****
