Back to Search
Start Over
Melting of CaSiO 3 Perovskite at High Pressure
- Source :
- Geophysical Research Letters
- Publication Year :
- 2019
- Publisher :
- American Geophysical Union (AGU), 2019.
-
Abstract
- Ab initio molecular dynamics simulations predict that CaSiO3 perovskite melts at 5600 K at 136 GPa, and 6400 K at 300 GPa, significantly higher than MgSiO3 perovskite. The entropy of melting (1.8 kB per atom) is much larger than that of many silicates at ambient pressure and of simple liquids and varies little with pressure. The volume of melting decreases rapidly with increasing pressure, to 3 % at 136 GPa, producing a melting slope that diminishes rapidly with pressure. We determine the melting temperature via the ZW method, combining the Z method, for which we clarify the theoretical basis, with a waiting time analysis. The ZW method results are internally confirmed by integrating the Clausius‐Clapeyron equation, which also yields our results for the entropy and volume of melting. We find the eutectic composition on the MgSiO3‐CaSiO3 join to be x Ca = 0.26 at 136 GPa and that metasilicate melt is denser than coexisting silicates.<br />Key Points Calcium silicate perovskite melts at 5600 K at the core mantle boundaryMetasilicate liquids are denser than coexisting crystalline silicates at the core‐mantle boundaryThe Z method allows precise ab initio melting temperature determination
- Subjects :
- Equations of State
Waiting time
melting
Materials science
010504 meteorology & atmospheric sciences
Melting temperature
Volcanology
Thermodynamics
010502 geochemistry & geophysics
01 natural sciences
Ab initio molecular dynamics
Research Letter
Composition of the Mantle
Solid Earth
Planetary Sciences: Solid Surface Planets
density functional theory
Mineralogy and Petrology
0105 earth and related environmental sciences
Eutectic system
Metasilicate
Interiors
magma ocean
Mineral Physics
silicate liquids
ab initio simulation
Research Letters
High-Pressure Behavior
Geochemistry
Tectonophysics
Geophysics
High pressure
General Earth and Planetary Sciences
Density functional theory
Cryosphere
mantle
Planetary Interiors
Ambient pressure
Subjects
Details
- ISSN :
- 19448007 and 00948276
- Volume :
- 46
- Database :
- OpenAIRE
- Journal :
- Geophysical Research Letters
- Accession number :
- edsair.doi.dedup.....37d99dc6a0daf5b3161cea4327ca545f