New host for carbon in the deep Earth.

ABSTRACT: The global geochemical carbon cycle involves exchanges between the Earth's interior and the surface. Carbon is recycled into the mantle via subduction mainly as carbonates and is released to the atmosphere via volcanism mostly as CO(2). The stability of carbonates versus decarbonation and melting is therefore of great interest for understanding the global carbon cycle. For all these reasons, the thermodynamic properties and phase diagrams of these minerals are needed up to core mantle boundary conditions. However, the nature of C-bearing minerals at these conditions remains unclear. Here we show the existence of a new Mg-Fe carbon-bearing compound at depths greater than 1,800 km. Its structure, based on three-membered rings of corner-sharing (CO(4))(4-) tetrahedra, is in close agreement wi

SUBMITTER: Boulard E 

PROVIDER: S-EPMC3069163 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature