The effect of oxygen fugacity and Na/(Na+K) ratio on iron speciation in pantelleritic glasses

The weak dependence of log (Fe3 +/Fe2 +) on log (fO2/bar) indicates a strong deviation from ideal mixing of iron species in pantelleritic compositions which suggests a different behaviour of alkali dominated peralkaline melts compared to other aluminosilicate melts in terms of fO2 and alkalis effects.