Thermodynamics for (Mg, Fe)2SiO4 from the Hugoniot
- Murli H. Manghnani and
- Yasuhiko Syono
Published Online: 21 MAR 2013
Copyright © 1987 by Terra Scientific Publishing Company (TERRAPUB), Tokyo.
High-Pressure Research in Mineral Physics: A Volume in Honor of Syun-iti Akimoto
How to Cite
Brown, J. M., Furnish, M. D. and Mcqueen, R. G. (1987) Thermodynamics for (Mg, Fe)2SiO4 from the Hugoniot, in High-Pressure Research in Mineral Physics: A Volume in Honor of Syun-iti Akimoto (eds M. H. Manghnani and Y. Syono), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM039p0373
- Published Online: 21 MAR 2013
- Published Print: 1 JAN 1987
Print ISBN: 9780875900667
Online ISBN: 9781118664124
- Mineralogy and Crystal Chemistry;
- Phase transformations;
- High Pressure-High Temperature Research
We review current knowledge of the compression behavior of magnesian olivine (Mg:(Mg+Fe)≥0.90) and its high-pressure decomposition products. Results from static and dynamic compression experiments are relatively consistent, although equation-of-state parameterizations remain uncertain. The dynamic compression experiments give Hugoniot parameters of C 0=6.57 and S=0.85 for a low-pressure phase and 3.80 and 1.69, respectively, for the high-pressure phase. The behavior of the isothermal bulk modulus for the high-pressure phase is compatible with the estimated properties of perovskite plus magnesiowustite. Preliminary sound velocities are reported for synthetic forsterite and San Carlos peridot shocked into the high-pressure phase. These data support our previous suggestion that the high-pressure phase of olivine melts near a Hugoniot pressure of 150 GPa. In addition, sound velocities below the inferred melting point match lower mantle longitudinal wave velocity profiles. At 168 GPa the measured velocity is consistent with a bulk sound velocity in a liquid having relatively large values for specific heat and the Grüneisen parameter. The solid-liquid mixed-phase regime probably extends beyond 168 GPa. Since limited data have been obtained for only one silicate phase, conclusions concerning compositional constraints for the lower mantle remain premature.