Fig. 6

Effect of pressure and oxygen fugacity on S isotope fractionation. Degassing-induced S isotope fractionation modelling using the starting isotopic composition of the inferred parental El Hierro magma, showing the relative effects of pressure (P) and oxygen fucacity (fO2). Strongly divergent paths are determined mainly by oxygen fugacity. Solid lines and dashed lines correspond to the fractionation factors of Miyoshi et al.42 and Fiege et al.45, respectively