Stability of calcium and magnesium carbonates at lower mantle thermodynamic conditions
| Autor: | João F. Justo, Michel L. Marcondes, Lucy V. C. Assali, Samuel S. M. Santos |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Condensed Matter - Materials Science
010504 meteorology & atmospheric sciences Magnesium CARBONATOS Thermodynamics chemistry.chemical_element Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Calcium 010502 geochemistry & geophysics 01 natural sciences Mantle (geology) Geophysics chemistry Space and Planetary Science Geochemistry and Petrology Ab initio quantum chemistry methods Earth and Planetary Sciences (miscellaneous) Chemical composition Geology 0105 earth and related environmental sciences |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| DOI: | 10.48550/arxiv.1804.07252 |
| Popis: | We present a theoretical investigation, based on ab initio calculations and the quasi-harmonic approximation, on the stability properties of magnesium (MgCO3) and calcium (CaCO3) carbonates at high temperatures and pressures. The results indicate that those carbonates should be stable in the Earth's lower mantle, instead of dissociating into other minerals, in chemical environments with excess of SiO2, MgO, or MgSiO3. Therefore, considering the lower mantle chemical composition, consisting mostly of the MgSiO3 and MgO minerals, calcium and magnesium carbonates are the primary candidates as carbon hosts in that region. For the thermodynamic conditions of the mantle, the results also indicate that carbon should be primarily hosted on MgCO3, contrasting with what was found by other theoretical studies, which neglected temperature effects. Finally, the results indicate that carbon, in the form of free CO2, is unlikely in the lower mantle. |
| Databáze: | OpenAIRE |
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