An extraterrestrial start and a volcanic end to the Cretaceous-Paleogene mass extinction?

Prof. Boswell Wing,
CU Boulder, Geological Sciences

"The Cretaceous–Paleogene (KPg) mass extinction is one of the “big five” mass extinctions that occurred during the last 550 million years. Although geological records of the KPg transition preserve ample evidence of an impact, there is significant controversy about whether this impact was the sole mass extinction trigger, or whether volcanism from the Deccan traps contributed significantly to the sudden onset of the biotic crisis. In this presentation I will discuss how precise measurements of the ratio of 34S-32S in KPg sediments at high-spatial resolution can trace atmospheric sulfur injections from these two events in the immediate vicinity of the KPg extinction horizon."