TY - JOUR
T1 - Single-crystal elastic properties of dense hydrous magnesium silicate phase A
AU - Sanchez-Valle, Carmen
AU - Sinogeikin, Stanislav V.
AU - Smyth, Joseph R.
AU - Bass, Jay D.
PY - 2006/5
Y1 - 2006/5
N2 - The single-crystal elastic properties of phase A have been investigated by Brillouin spectroscopy at ambient conditions. The Voigt-Reuss-Hill average for the adiabatic bulk and shear moduli are Ks = 106(1) GPa and μ = 61(1) GPa respectively. The present acoustic measurements resolve discrepancies between the bulk moduli obtained in earlier compression studies. The axial compressibility of the hexagonal (P63) structure is highly anisotropic with the c-axis, which is perpendicular to the distorted close-packed layers, approximately 21% stiffer than the α-axis, in agreement with previous compression studies. The hydration of forsterite to phase A decreases the bulk and shear moduli by about 18 and 21%, respectively, while both compressional Vp and shear Vs wave velocities decrease by about 7%. These results suggest that water could be identified seismologically if phase A is present in abundance in cold subducted slabs.
AB - The single-crystal elastic properties of phase A have been investigated by Brillouin spectroscopy at ambient conditions. The Voigt-Reuss-Hill average for the adiabatic bulk and shear moduli are Ks = 106(1) GPa and μ = 61(1) GPa respectively. The present acoustic measurements resolve discrepancies between the bulk moduli obtained in earlier compression studies. The axial compressibility of the hexagonal (P63) structure is highly anisotropic with the c-axis, which is perpendicular to the distorted close-packed layers, approximately 21% stiffer than the α-axis, in agreement with previous compression studies. The hydration of forsterite to phase A decreases the bulk and shear moduli by about 18 and 21%, respectively, while both compressional Vp and shear Vs wave velocities decrease by about 7%. These results suggest that water could be identified seismologically if phase A is present in abundance in cold subducted slabs.
KW - Brillouin spectroscopy
KW - Phase A
KW - Single-crystal elasticity
KW - Water in subduction zones
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U2 - 10.2138/am.2006.2193
DO - 10.2138/am.2006.2193
M3 - Article
AN - SCOPUS:33745460939
SN - 0003-004X
VL - 91
SP - 961
EP - 964
JO - American Mineralogist
JF - American Mineralogist
IS - 5-6
ER -