Elastic properties of hydrogrossular garnet and implications for water in the upper mantle

B. O'Neill, Jay D Bass, G. R. Rossman

Research output: Contribution to journalArticle

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 languageEnglish (US)
JournalJournal of Geophysical Research
Volume98
Issue numberB11
StatePublished - Jan 1 1993
Externally publishedYes

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elastic property
Garnets
garnets
shears
upper mantle
garnet
Earth mantle
elastic properties
bulk modulus
Elastic moduli
shear modulus
Water
silicates
water
shear
mantle
crystals
eclogite
grossular
seismic waves

ASJC Scopus subject areas

  • Geophysics
  • Oceanography
  • Forestry
  • Aquatic Science
  • Ecology
  • Condensed Matter Physics
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Physical and Theoretical Chemistry
  • Polymers and Plastics
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Materials Chemistry
  • Palaeontology

Cite this

Elastic properties of hydrogrossular garnet and implications for water in the upper mantle. / O'Neill, B.; Bass, Jay D; Rossman, G. R.

In: Journal of Geophysical Research, Vol. 98, No. B11, 01.01.1993.

Research output: Contribution to journalArticle

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