Acoustic velocities of pure and iron-bearing magnesium silicate perovskite measured to 25 GPa and 1200 K
Article first published online: 12 OCT 2012
©2012. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 39, Issue 19, 16 October 2012
How to Cite
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., , , , and (
- Issue published online: 12 OCT 2012
- Article first published online: 12 OCT 2012
- Manuscript Accepted: 12 SEP 2012
- Manuscript Revised: 11 SEP 2012
- Manuscript Received: 11 JUL 2012
- lower mantle;
 Ultrasonic interferometry measurements in conjunction with in situ X-ray techniques have been used to measure compressional and shear wave velocities and densities of MgSiO3perovskite (Mg-Pv) and Mg0.95Fe0.042+Fe0.013+SiO3perovskite ((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 lowKSvalue 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.