Sulfur isotope distribution in sulfides and sulfates from Broken Hill South, New South Wales

Sphalerite and galena are the dominant primary ore minerals found in the Broken Hill orebody of western New South Wales and both occur in minor amounts as supergene suifides, especially at Broken Hill South. Isotope values for the primary sulfides sigma S34 range from 0 to +1.7. Secondary sulfates of the same metals (anglesite and goslarite) follow these figures very closely. The sphalerite and galena of supergene origin are among the highest sigma S34 values yet recorded averaging -43.3 and reaching --51.9. This is considered due to near optimum conditions of freedom of circulation of the downward moving ground waters and thus to maximum availability of the two sulfur isotopes.