Stability of Perovskite (MgSiO 3 ) in the Earth's Mantle
- 22 November 1996
- journal article
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 274 (5291) , 1357-1359
- https://doi.org/10.1126/science.274.5291.1357
Abstract
Available thermodynamic data and seismic models favor perovskite (MgSiO3) as the stable phase in the mantle. MgSiO3 was heated at temperatures from 1900 to 3200 kelvin with a Nd-YAG laser in diamond-anvil cells to study the phase relations at pressures from 45 to 100 gigapascals. The quenched products were studied with synchrotron x-ray radiation. The results show that MgSiO3 broke down to a mixture of MgO (periclase) and SiO2 (stishovite or an unquenchable polymorph) at pressures from 58 to 85 gigapascals. These results imply that perovskite may not be stable in the lower mantle and that it might be necessary to reconsider the compositional and density models of the mantle.Keywords
This publication has 11 references indexed in Scilit:
- FeFeS eutectic temperatures to 620 kbarPhysics of the Earth and Planetary Interiors, 1996
- Earth mineralogical model: Gibbs free energy minimization computation in the system MgOFeOSiO2Geochimica et Cosmochimica Acta, 1996
- Thermoelastic properties of MgSiO3 perovskite determined by in situ X ray observations up to 30 GPa and 2000 KJournal of Geophysical Research, 1996
- Molecular dynamics of NaCl (B1 and B2) and MgO (B1) melting; two-phase simulationAmerican Mineralogist: Journal of Earth and Planetary Materials, 1996
- Measurement of melting temperatures of some minerals under lower mantle pressuresJournal of Geophysical Research, 1995
- ILR1, an Amidohydrolase That Releases Active Indole-3-Acetic Acid from ConjugatesScience, 1995
- High-Temperature Phase Transition and Dissociation of (Mg, Fe)SiO 3 Perovskite at Lower Mantle PressuresScience, 1995
- Transformation of stishovite to a denser phase at lower-mantle pressuresNature, 1995
- A new, post-stishovite highpressure polymorph of silicaNature, 1989
- The mineralogy and chemistry of the lower mantle: an implication of the ultrahigh-pressure phase relations in the system MgO FeO SiO2Earth and Planetary Science Letters, 1984