The sulfur isotopic composition of Neoproterozoic to early Cambrian seawater — evidence from the cyclic Hanseran evaporites, NW India

The sulfur isotopic composition has been determined for terminal Neoproterozoic to early Cambrian evaporites from the Hanseran Group in NW India. δ34S values, ranging from +27.5‰ to +39.7‰ vs. Canyon Diablo Troilite (CDT) (n=26), further substantiate the strongly positive sulfur isotope signature of contemporaneous seawater. Distinct stratigraphic variations in δ34S within this succession suggest secular variations in seawater composition which might be of global importance. Overall, this documents major pertubations of the sulfur cycle in response to paleooceanographic changes trailing tectonic, climatic and/or biological rearrangements during the Neoproterozoic and early Paleozoic.