The First Discovery of Isotopic (δ34S, Δ33S) Sulfur Anomalies in Authigenic Sulfides from the Permian–Triassic Boundary Deposits of Siberia

A unique discovery of isotopic anomalies established by studying the ratios of three stable sulfur isotopes (32S, 33S, and 34S) in authigenic sulfides from sedimentary rocks formed at the end of the Permian period (~252 Ma ago) in northeastern Asia (Suol section, Southern Verkhoyanye, Eastern Siberia) is reported. The range of δ34S variations reaches 65‰, the deviation of Δ33S values from zero values varies from 0.11‰ to 0.46‰. The presence of sulfur isotopic anomalies at high paleolatitudes of the Boreal Superrealm has been recorded for the first time. The anomalies indicate intense UV fluxes penetrating the Earth’s atmosphere, which may be related to the weakening of ozone protection as a result of the decrease in magnetic field intensity and the release of large amounts of gaseous sulfur compounds and halogens into the atmosphere during massive volcanic eruptions. Active hard UV radiation had a direct, deadly effect on both terrestrial and marine (primarily surface plankton) biota.