Figure 7
Plot of δ34S vs. ∆33S for the Bruddesta pyrite and galena precipitates, compared to present-day biogenic and hydrothermal sulphide and vent H2S from the East Pacific Rise and Mid-Atlantic Ridge41 and sedimentary pyrites from the Ediacaran‒Cambrian transition42. The model fields illustrate the field of S-isotope compositions produced by sulphate reduction where disproportionation could occur but not required (black outlined field) and sulphate reduction combined with sulphur disproportionation (black dotted line field)43,44.
