Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4742974 | Physics of the Earth and Planetary Interiors | 2006 | 12 Pages |
Abstract
Acoustic wave velocities for synthetic polycrystalline pyrope (Mg3Al2Si3O12) were measured to 9 GPa and temperatures up to 1000 °C by ultrasonic interferometry combined with energy-dispersive synchrotron X-ray diffraction in a cubic-anvil DIA-type apparatus (SAM-85). Specimen lengths at high pressures (P) and temperatures (T) are directly measured by X-radiographic methods. Elastic wave travel times and X-ray diffraction data were collected after heating and cooling at high pressures to minimize effect of non-hydrostatic stress on the measurements. A linear fit to the high P and T data set yields the elastic bulk and shear moduli [KS = 175 (2) GPa; G = 91 (1) GPa] and their pressure and temperature derivatives [Kâ²S=3.9±0.3; Gâ²Â = 1.7 ± 0.2 and (âKS/âT)P = â18 (2) MPa/K; (âG/âT)P = â10 (1) MPa/K]. In a separate analysis, the pressure-volume-temperature data collected during these acoustic experiments were fit to a high temperature Birch-Murnaghan (HTBM) equation [with Kâ² fixed at 3.9] and to each isothermal P-V-T data yielding (âKT/âT)P = â22 (2) MPa/K and (âKT/âT)P = â20 (5) MPa/K, respectively. Comparison of Py100 data with those other Py-Mj compositions indicates that the thermo elastic properties are insensitive to majorite content in the garnet along the pyrope-majorite join.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geophysics
Authors
Gabriel D. Gwanmesia, Jianzhong Zhang, Kenneth Darling, Jennifer Kung, Baosheng Li, Liping Wang, Daniel Neuville, Robert C. Liebermann,