Ultrasonic measurements of the elastic wave velocities of olivine and beta polymorphs of magnesium silicon oxide at mantle transition zone P and T and geophysical implications

New techniques for acoustic velocity measurements on millimeter sized specimens have been developed to pressures greater than 12 GPa at room temperature and at simultaneous pressure and temperature to 10 GPa 1000;The feasibility of performing direct velocity measurements on millimeter sized specimens to the mantle transition zone pressure and temperature using ultrasonic interferometry in the same high pressure apparatus has been demonstrated by preliminary experiments on polycrystalline forsterite to 10 GPa and 1030...