We present high-resolution sulfur and carbon isotope records from the cap carbonate of the Doushantuo Formation, South China, a unique suite of depositional facies spanning across a pronounced paleo-oceanic depth gradient. The δ 34 S of carbonate-associated sulfate (CAS) decreases across a shelf-to-slope depth transect. We propose that the deeper-water slope profile represents syn-glacial sulfur isotope compositions of the seawater sulfates with impact of 34 S-depleted hydrothermal sulfur inputs, while the δ 34 S of the shallow inner-shelf were dominantly controlled by the 34 S-enriched terrigenous input. We suggest that the terrigenous sulfur inputs were mainly from weathering and erosion of the pre-Marinoan Datangpo Formation—glacially ground and then freshly exposed during rapid deglaciation. The widespread Datangpo Formation, deposited between the Sturtian and Marinoan glacial intervals, is noted for the unusually high δ 34 S values of its pyrite.The low sulfate conditions in the ocean allowed for strong local controls and consequent heterogeneities in seawater chemistry. The post-Marinoan ocean was stratified in the immediate wake of glaciation, with anoxic deep waters overlain by an oxic, melt-water layer. During the transgression, the shallow water was disturbed by upwelling. The oxidation of dissolved organic carbon (DOC) from deep water would lead to transiently enhanced 13 C depletions but 34 S enrichments in the shallow waters.