The Start of Sulfur Oxidation in Continental Environments: About 2.2 × 10 9 Years Ago

Abstract
Whereas dissimilatory sulfate reduction in marine environments has been postulated on the basis of sulfur isotope abundances as commencing before about 2.8 x 109 years ago, data from the Huronian Supergroup, Canada, suggest that oxidative-reductive reactions involving sulfur in continental environments were not significant before about 2.2 x 109 years ago.