Sulfur isotope profiles in the pelagic Panthalassic deep sea during the Permian–Triassic transition

Abstract

Mesozoic accretionary complexes in Japan and New Zealand contain Panthalassic low latitude and southern mid-latitude deep-water sedimentary rock respectively. These sedimentary rocks record environmental changes in the pelagic Panthalassic Ocean during the transition associated with the severe Permian–Triassic mass extinction. This study presents sulfur isotope records of sulfide from continuous deep-sea Permian–Triassic boundary sections located in northeast Japan (the Akkamori section-2, the most continuous section among other previously reported deep-sea sections) and North Island of New Zealand (the Waiheke-1 section, providing the first sulfur isotopic record from a southern hemisphere deep-sea section). Both sections show sharp ~15‰ drops of the sulfur isotope ratio coupled with a negative shift of organic carbon isotope ratio. Similar decreases in sulfur isotope ratio of carbonate-associated sulfates by ~10‰ accompanied with a negative shift of inorganic carbon isotope ratio at the end-Permian mass extinction horizon have been reported in some shallow water Paleotethyan sections. These sulfur isotope changes suggest that a massive release of 32S-enriched sulfur from the H2S-rich water to the oxic surface-waters coincided with the end-Permian mass extinction.