Acoustic velocities of pure and iron-bearing magnesium silicate perovskite measured to 25 GPa and 1200 K

作者：Chantel, Julien^*; Frost, Daniel J.; McCammon, Catherine A.; Jing, Zhicheng; Wang, Yanbin

来源：Geophysical Research Letters, 2012, 39: L19307.

DOI：10.1029/2012GL053075

• EQUATION-OF-STATE
• MGSIO3 PEROVSKITE
• LOWER MANTLE
• CRYSTAL-STRUCTURE
• SOUND-VELOCITY
• HIGH-PRESSURE
• TEMPERATURE
• EARTH
• SPECTROSCOPY
• PARAMETERS

Ultrasonic interferometry measurements in conjunction with in situ X-ray techniques have been used to measure compressional and shear wave velocities and densities of MgSiO3 perovskite (Mg-Pv) and Mg0.95Fe0.042+Fe0.013+SiO3 perovskite ((Mg, Fe)-Pv) in the multianvil at pressures up to 25 GPa and temperatures to 1200 K. Data for Mg-Pv are consistent with previous studies and the (Mg, Fe)-Pv sample has almost identical shear properties to Mg-Pv. The adiabatic bulk modulus, Ks, for (Mg, Fe)-Pv, however, is found to be substantially lower than Mg-Pv, with a refined value of 236 GPa and a pressure derivative of 4.7. It is proposed that this low K-S value result from a change in the elasticity of Fe-bearing perovskite at low pressures <30 GPa. High temperature data are consistent with recent models and it is shown that the obtained elastic properties of (Mg, Fe)-Pv are not inconsistent with a lower mantle of bulk silicate Earth composition. Citation: Chantel, J., D. J. Frost, C. A. McCammon, Z. Jing, and Y. Wang (2012), Acoustic velocities of pure and iron-bearing magnesium silicate perovskite measured to 25 GPa and 1200 K, Geophys. Res. Lett., 39, L19307, doi:10.1029/2012GL053075.

• 出版日期2012-10-12