Carbon-bearing silicate melt at deep mantle conditions.

ABSTRACT: Knowledge about the incorporation and role of carbon in silicate magmas is crucial for our understanding of the deep mantle processes. CO₂ bearing silicate melting and its relevance in the upper mantle regime have been extensively explored. Here we report first-principles molecular dynamics simulations of MgSiO₃ melt containing carbon in three distinct oxidation states - CO₂, CO, and C at conditions relevant for the whole mantle. Our results show that at low pressures up to 15 GPa, the carbon dioxide speciation is dominated by molecular form and carbonate ions. At higher pressures, the dominant species are silicon-polyhedral bound carbonates, tetrahedral coordination, and polymerized di-carbonates. Our results also indicate that CO₂ component rem

SUBMITTER: Ghosh DB 

PROVIDER: S-EPMC5429813 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature