The fate of carbon dioxide in water-rich fluids under extreme conditions.

ABSTRACT: Investigating the fate of dissolved carbon dioxide under extreme conditions is critical to understanding the deep carbon cycle in Earth, a process that ultimately influences global climate change. We used first-principles molecular dynamics simulations to study carbonates and carbon dioxide dissolved in water at pressures (P) and temperatures (T) approximating the conditions of Earth's upper mantle. Contrary to popular geochemical models assuming that molecular CO₂(aq) is the major carbon species present in water under deep Earth conditions, we found that at 11 GPa and 1000 K, carbon exists almost entirely in the forms of solvated carbonate ([Formula: see text]) and bicarbonate ([Formula: see text]) ions and that even carbonic acid [H₂CO₃(aq)]

SUBMITTER: Pan D 

PROVIDER: S-EPMC5061492 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature