Abstract
The single-crystal elastic moduli of natural samples of grossular (99.0 mol % Ca3Al2Si3O12) and spessartite (94.8 mol % Mn3Al2Si3O12) have been measured by Brillouin spectroscopy under ambient conditions. From these results the adiabatic bulk moduli Ks and shear moduli μ are calculated to be Ks = 168.4 ± 0.7, μ = 108.9 ± 0.4 for grossular, and Ks = 178.8 ± 0.8, μ 96.3 ±0.5 for spessartite (all in units of gigapascals). Of the major rock-forming silicate garnets, spessartite has the largest bulk modulus, and grossular has the largest shear modulus, with the possible exception of majorite (a high-pressure form of pyroxene). Approximate values for the bulk and shear moduli of common aluminosilicate garnet solid solutions can be obtained with an estimated uncertainty of less than 3% from a linear molar average of the end-member properties. The elastic properties of pure almandite garnet (Fe3Al2Si3O12), which have thus far not been measured, are estimated as Ks = 177 ± 3 and μ = 97 ± 1 GPa by a linear regression analysis of extant measurements on garnet solid solutions and end-members. -from Author
Original language | English (US) |
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Pages (from-to) | 7621-7628 |
Number of pages | 8 |
Journal | Journal of Geophysical Research |
Volume | 94 |
Issue number | B6 |
DOIs | |
State | Published - 1989 |
ASJC Scopus subject areas
- Geophysics
- Forestry
- Oceanography
- Aquatic Science
- Ecology
- Water Science and Technology
- Soil Science
- Geochemistry and Petrology
- Earth-Surface Processes
- Atmospheric Science
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science
- Palaeontology