Abstract
The single-crystal elastic properties of a hydrous silicate garnet, hibschite, were measured using Brillouin spectroscopic techniques. The adiabatic bulk modulus of hibschite, Ks = 99.8 ± 1.0 GPa, and the shear modulus, μ = 64.3 ± 0.5 GPa, are 40% lower than the bulk and shear moduli for anhydrous grossular garnet. Density considerations indicate that hydrogarnet is likely to be stable relative to an assemblage with H2O as a separate phase throughout the upper mantle and probably the transition zone. Assuming garnet to be the sole repository for mantle water, the seismic wave velocities of a "wet' eclogitic layer are 6-8% lower than those of dry eclogite. A hydrated eclogitic layer several times thicker than the oceanic crust would probably be required for a water-rich region of the mantle to be seismologically detectable. -from Authors
Original language | English (US) |
---|---|
Pages (from-to) | 20,031-20,037 |
Journal | Journal of Geophysical Research |
Volume | 98 |
Issue number | B11 |
DOIs | |
State | Published - 1993 |
Externally published | Yes |
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