Ultrasonic P Wave Velocity and Attenuation in Pyroxenite Under 3.0 GPa up to 1170°C

Ultrasonic P wave velocity (V_P) and quality factor (Q_P value, on behalf of attenuation) in pyroxenite were presented as functions of pressures (0.3-3.0 GPa) and temperatures (20-1170°C). The experimental results show that V_P and Q_P depend upon pressure and temperature. V_P and Q_P in pyroxenite increase more rapidly at the pressure 0.3-1.4 GPa than those at 1.4-3.0 GPa. As the temperature rising from 20°C to about 1170°C at the pressure 3.0 GPa, an almost linear decrease up to 11% in V_P was observed, and Q_P drops from 243 at room temperature to 68 at 1170°C with the decrease of 72 %. The experimental data indicate that the pressure and temperature induced fabric changes and frictional sliding and dislocation in pyroxenite play a key role in wave propagation in rocks.