A recent study provides insight into the recovery of marine ecosystems following the end-Permian mass extinction. The research focuses on the sulfur cycle during this time, and reports carbonate carbon and oxygen, carbonate-associated sulfate (CAS) sulfur and oxygen, and pyritic sulfur isotopic ratios from samples covering the Smithian-Spathian substage boundary (SSB). The section was obtained from the Jesmond section, Cache Creek Terrane, western Canada, which was formed as a tropical atoll in the Panthalassic Ocean.

The results allow for estimates of paleo-seawater sulfate concentrations, with Early Triassic seawater sulfate estimates of 2.5 to 9.1 mM being higher than in previous studies of the Permian-Triassic boundary.

The study, “Sulfur-isotope evidence for recovery of seawater sulfate concentrations from a PTB minimum by the Smithian-Spathian transition,” was published in the journal Earth-Science Reviews. The work was performed at the NSF/NASA Center for Chemical Evolution (CCE) at the Georgia Institute of Technology in Atlanta, Georgia. The CCE is a collaborative program supported by the National Science Foundation (NSF) and the NASA Astrobiology Program.