The effect of sulfur degassing on oxygen fugacity of basaltic melt; a preliminary result using equilibrium batch degassing model

Abstract

The effect of sulfur degassing on fO₂ condition of the petit-spot site-B basaltic melt is numerically examined assuming equilibrium batch degassing. The results indicate that the effect of S degassing on fO₂ of melt depends on initial fO₂ condition of melt. At fO₂ ~ QMF+0.7, sulfur degassing does not influence on melt fO₂ condition. For melt more/less oxidized than QMF+0.7, melt fO₂ increases/decreases as S degasses. By considering < 2000 ppm of sulfur degassing, initial fO₂ condition of petit spot melt is estimated to be > QMF+1.4, indicating arc-like fO₂ condition of petit-spot mantle.