Elasticity of High Pressure Mantle Garnet Phases at High Pressures and High Temperatures

Delaware State University, Dover DE

Investigators

Abstract

Gwanmesia 0106528 The study is to make precise measurement of the acoustic wave velocities at simultaneous high-pressures and temperatures (P-Vp-Vs-T measurements) and the equation of state (P-V-T relations) for Mg3Al2Si3O12-pyrope garnet. The experiments will be conducted in a cubic anvil DIA-type high pressure apparatus, SAM-85, which is installed on the super conducting wiggler beam line (X17B1) at the National Synchrotron Light Source of the Brookhaven National laboratory. The high pressure and high temperature elasticity data, as well as the equation of state data, will be compared with data for Mg3Al2Si3O12-pyrope garnet obtained by other elasticity techniques using single-crystal or polycrystalline specimens. The study will utilize existing polycrystalline specimens of Mg3Al2Si3O12-pyrope garnet and other new specimens hot-pressed in a 2000-ton uniaxial split-sphere apparatus (USSA-2000) at conditions up to 5 GPa, and 1350C. Samples will be characterized by x-ray diffraction, optical, scanning and transmission electron microscopy and by bench top ultrasonic techniques, to ensure that the specimens are singled-phase, fine-grained and pore- and crack-free.