Two pulses of oceanic environmental disturbance during the Permian–Triassic boundary crisis

Pyrite morphology, iron speciation, and pyrite sulfur isotope data from the Xiakou section (Hubei Province, South China) were integrated to explore oceanic environmental variations through the Permian–Triassic transition and their possible relations to the largest mass extinction in Earth history. High ratios of highly-reactive iron to total iron (FeHR/FeT > 0.6) and pyrite iron to highly-reactive iron (FePy/FeHR > 0.7) together with a high...