Recurring volcanic winters during the latest Cretaceous: Sulfur and fluorine budgets of Deccan Traps lavas

Abstract

Two events share the stage as main drivers of the Cretaceous-Paleogene mass extinction—Deccan Traps volcanism, and an asteroid impact recorded by the Chicxulub crater. We contribute to refining knowledge of the volcanic stressor by providing sulfur and fluorine budgets of Deccan lavas from the Western Ghats (India), which straddle the Cretaceous-Paleogene boundary. Volcanic fluorine budgets were variable (400 to 3000 parts per million) and probably sufficient to affect the environment, albeit only regionally. The highest sulfur budgets (up to 1800 parts per million) are recorded in Deccan lavas emplaced just prior (within 0.1 million years) to the extinction interval, whereas later basalts are generally sulfur-poor (up to 750 parts per million). Independent evidence suggests the Deccan flood basalts erupted in high-flux pulses. Our data suggest that volcanic sulfur degassing from such activity could have caused repeated short-lived global drops in temperature, stressing the ecosystems long before the bolide impact delivered its final blow at the end of the Cretaceous.

Geochronological Constraints on the Evolution and Petrogenesis of the Malwa Plateau Subprovince of the Deccan Traps

“…The Deccan Traps were the first continental LIP to have been invoked as a driver of mass extinctions and/or periods of major ecological change (Callegaro et al., 2023; Courtillot et al., 1986; McLean, 1985). The relationship of Deccan magmatic activity with the Cretaceous—Paleogene boundary (KPB) extinctions remains ambiguous and warrants continued investigation.…”