[S-CG57] Dynamics in mobile belts

[SCG57-P32] Ultrasonic velocity measurements of plycrystalline clinopyroxene under high P-T conditions

*Yumiko Tsubokawa¹, Masahiro Ishikawa¹ (1.Yohokohama National University)

Keywords:elastic velocity, clinopyroxene, submicron

Ultrasonic elastic velocity measurements of polycrystalline clinopyroxene with submicron-sized grains were conducted under high P-T conditions in a piston-cylinder apparatus. We prepared nano-sized powders of clinopyroxene from naturally occurring clinopyroxene single crystal and successfully fabricated fine-grained polycrystalline clinopyroxene. P and S wave velocities are determined as a function of pressure to 1.0 GPa at temperatures up to 650 °C for Vp and 750 °C for Vs. At room temperature, Vp, Vs and Vp/Vs increased during pressurization. On the other hand, at 1.0 GPa, Vp and Vs decreased and Vp/Vs slightly increased with increasing temperature. From P and S wave velocities and estimated density, we calculated the elastic constants of clinopyroxene and found that the bulk modulus obtained in this study is smaller than previously published data.