Redox processes and the role of carbon-bearing volatiles from the slab–mantle interface to the mantle wedge

The valence of carbon is governed by the oxidation state of the host system. The subducted oceanic lithosphere contains considerable amounts of iron so that Fe 3+ /Fe 2+ null equilibria in mineral assemblages are able to buffer the null f O 2 null and the valence of carbon. Alternatively, carbon itself can be a carrier of redox budget when transferred from the slab to the mantle, prompting the oxidation of the sub-arc mantle. Also, the oxidation...