• journal_title：American Mineralogist
• Contributor：Carmen Sanchez-Valle ; Stanislav V. Sinogeikin ; Joseph R. Smyth ; Jay D. Bass
• Publisher：Mineralogical Society of America
• Date：2006-
• Format：text/html
• Language：en
• Identifier：10.2138/am.2006.2193
• journal_abbrev：American Mineralogist
• issn：0003-004X
• volume：91
• issue：5-6
• firstpage：961
• section：Letters

d="p-1">The single-crystal elastic properties of phase A have been investigated by Brillouin spectroscopy at ambient conditions. The Voigt-Reuss-Hill verage for the adiabatic bulk and shear moduli are K_S = 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 a-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 V_P and shear V_S 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.