Ultrasonic measurements of the sound velocities in polycrystalline San Carlos olivine in multi-anvil, high-pressure apparatus

Sound velocities in polycrystalline San Carlos olivine have been measured to pressures of 7 GPa at room temperature in a 1000 t uniaxial, split-cylinder apparatus (USCA-1000) of the Kawai multi-anvil type. These velocities and elastic moduli are in good agreement with those calculated from single-crystal moduli determined by previous investigators. In preliminary experiments in a DIA-type, cubic anvil apparatus (SAM-85), ultrasonic interferometric techniques were used in conjunction with synchrotron X-radiation to determine the elastic properties of San Carlos olivine under simultaneous high pressures and temperatures. We demonstrate the feasibility of such experiments even in specimens which have undergone plastic deformation at elevated pressures and temperatures.