Diffusion pathways of Fe2+ and Fe3+ during the formation of ferrian chromite: a µXANES study

The alteration of chromian spinel is a key process during serpentinization and metamorphism of ultramafic rocks controlled by oxygen fugacity (fO2) and Fe2+ ↔ Fe3+ exchange during fluid–rock interaction. Chromian spinel alteration is better recorded in less permeable chromitite than in peridotites where extensive fluid–rock interaction frequently overprints the record of earlier stages of alteration. To shed light on that process we have studied...