Sulfur and carbon isotopic variations in Neoproterozoic sedimentary rocks from southern China

A new set of δ 34S sulfide, δ 34S sulfate and δ 13C carbonate values has been reported from Neoproterozoic sedimentary rocks in southern China. The interglacial black shales of the Datangpo Fm. display higher δ 34S sulfide values with >+20‰ average, but the postglacial black shales from the Doushantuo Fm. show negative δ 34S sulfide values. However, the Jinjiadong Fm., the same post-glaciation as the Doushantuo Fm., has positive δ 34S sulfide values, implying that the δ 34S value of sedimentary sulfides would be controlled by lithofacies and paleogeographic environments. The δ 34S sulfate values relative to δ 13C carbonate were obtained by extraction of trace sulfate from the successive carbonate sequences in the Yangtze Gorges sections. A preliminary interpretation suggests that the oceanic environment may fluctuate dramatically at the post-glacial Doushantuo stage and, then, recover its stability at the Dengying stage on the basis of the high resolution δ 34S and δ 13C curves of seawater.