Reduced contribution of sulfur to the mass extinction associated with the Chicxulub impact event

Katerina Rodiouchkina, Steven Goderis, Ozgur Karatekin, Philippe Claeys , Michael Boettcher, Frank Vanhaecke, Cem Berk Senel, Ilia Rodushkin, Orkun Temel, Johan Vellekoop, Pim Kaskes

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 a main driving force. Yet, the magnitude of the S release remains poorly constrained. Here, the amount of impact-released S is estimated empirically relying on the concentration of S and its isotopic composition within the impact structure and a set of terrestrial K-Pg boundary ejecta sites for the first time. The value of 67 ± 39 Gt obtained is ~5-fold lower than recent numerical estimates but concurs with numerical estimates from the 1990s. The lower mass of S-released implies global average temperatures above freezing point with key implications for species survival during the first years following the impact.