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Stratiform barite beds, interlayered with (fuchsite) quartzites and mafic metavolcanics and containing minor disseminations of sulfides, occur in the Archaeagn (> 3.3 Ga) Sargur Group of rocks at Ghattihosahalli, in the state of Karnataka, south India and near Jagat, within quartzites and metamorphosed flood basalts underlying the middle Proterozoic (∼ 2.0 Ga) Aravalli Supergroup in the state of Rajasthan, northwest India (Fig. 1). The Sargur barites have δ 34 S in the range of 4.02 to 7.45‰(x ̄= 5.40‰). Disseminations of detrital pyrite, occurring in layers in the barite have δ 34 S between− 3.62 and− 5.87‰. These barites are also characterized by low 87 Sr 86 Sr ratios (∼ 0.7018±7). The basal Aravalli barites, in contrast, have exceptionally high 87 Sr 86 Sr ratios (0.72284 to 0.72382) and δ 34 S between 17.11 and 21.24‰(o ̄ vbar| x= 18.75‰). δ 34 S in disseminated chalcopyrite within banded barite …