Spatio-temporal volume recalibration shows Deccan volcanism caused Terminal Cretaceous Mass Extinctio

Abstract

The recognition of Deccan flood basalts as a causal mechanism for the Terminal Cretaceous Mass Extinction has been contentious. Our computation of their spatio-temporal distribution reiterates that ∼1.5 million km3 of the Deccan flood basalts erupted in <700 k.y., during Chron C29r (66.31−65.73 Ma) straddling the 66.05 Ma Cretaceous-Paleogene boundary (KPgB). Unlike earlier projections, we demonstrate that ∼70% of these lavas erupted in the terminal Maastrichtian before the KPgB. The toxic degassing of the lavas in the ∼300 k.y. prior to the KPgB set the stage for mass extinction. The early Danian lavas contributed to the delayed biotic recovery.