Sulphur isotopes in Permian–Triassic evaporites: an 80‐million‐year record of pyrite burial

The Permian–Triassic time interval is associated with major perturbations in the biogeochemical cycling of several redox-sensitive elements. In particular, sulphur isotope ratios (δ34S) reveal substantial perturbations in sedimentary sulphates. Despite this, few studies utilise this δ34S variability for long-term high-resolution correlation. Through the sulphur isotope analysis of sedimentary evaporites of the Staithes S-20 borehole (northeast England), we have generated the most stratigraphically complete evaporite sulphur isotope (δ34Sevap) curve from a single stratigraphic section for the late Permian to Late Triassic. The Staithes S-20 record and its comparison with the global δ34Sevap curve demonstrate the utility of sulphur isotope data for stratigraphic correlation and dating, especially evaporite bearing sequences. The δ34Sevap data for the late Permian to Late Triassic were incorporated into a biogeochemical box model to yield estimates for the pyrite burial flux with time. We propose three significant pyrite burial events (i.e. PBEs) throughout the Triassic. Our model outputs predict a major increase in pyrite burial over the Permian/Triassic boundary, possibly driven by Siberian Traps volcanism. After ~10 million years, the pyrite burial flux achieves relative stability until the latest Triassic.