Kinetics of High-Pressure Transformations in Earth's Mantle Minerals

Abstract

Kinetics of high-pressure transformations in Earth's mantle minerals have been studied up to 35 GPa and 2,000 K based on time-resolved X-ray diffraction measurements with energy-dispersive method by combining Kawai-type high-pressure apparatus and synchrotron radiation. Kinetic behaviors are different among various types of transformations occurred in the mantle transition zone, and the rates of transformations depend on not only temperatures but also water contents. These metastable phase transformations would affect the density and viscosity of the down going cold current of mantle convection.