PRESSURE DERIVATIVES OF ELASTIC PROPERTIES OF POLYCRYSTALLINE QUARTZ AND RUTILE

Ultrasonic measurements at 298°K as a function of hydrostatic pressure to 7 Kb for polycrystalline quartz and rutile yield the following values of pressure coefficients of the velocities of compressional (P) and shear (S) waves, the adiabatic bulk modulus (KS), and its isothermal pressure derivative: {A table is presented} These data are discussed in relation to the structure and the phase instability at high pressure. The relatively small values of (∂ ℓn VS/∂P)T may indicate that neither high thermal gradient nor partial melting is required to account for the low velocity layer in the earth. © 1969.