Author:

Keywords:

STG/21/026#56734393, Science & Technology, Multidisciplinary Sciences, Science & Technology - Other Topics, CRETACEOUS-TERTIARY BOUNDARY, K-PG BOUNDARY, PALEOGENE BOUNDARY, ASTEROID IMPACT, STEVNS-KLINT, BRAZOS RIVER, IRIDIUM, CRATER, CLIMATE, SULFATE, Extinction, Biological, Animals, Dinosaurs, Sulfur, Fossils, Sulfur Isotopes

Abstract:

The Chicxulub asteroid impact event at the Cretaceous-Paleogene (K-Pg) boundary ~66 Myr ago is widely considered responsible for the mass extinction event leading to the demise of the non-avian dinosaurs. Short-term cooling due to massive release of climate-active agents is hypothesized to have been crucial, with S-bearing gases originating from the target rock vaporization considered an important driving force. Yet, the magnitude of the S release remains poorly constrained. Here we empirically estimate the amount of impact-released S relying on the concentration of S and its isotopic composition within the impact structure and a set of terrestrial K-Pg boundary ejecta sites. The average value of 67 ± 39 Gt obtained is ~5-fold lower than previous numerical estimates. The lower mass of S-released may indicate a less prominent role for S emission leading to a milder impact winter with key implications for species survival during the first years following the impact.