| Autor: |
Callegaro S; Centre for Earth Evolution and Dynamics, University of Oslo, Sem Sælands vei 2A, 0371 Oslo, Norway.; Centre for Planetary Habitability, University of Oslo, Sem Sælands vei 2A, 0371 Oslo, Norway., Baker DR; Department of Earth and Planetary Sciences, McGill University, 3450 University St., Montreal, QC, Canada., Renne PR; Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA 94709, USA.; Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA 94720, USA., Melluso L; Dipartimento di Scienze della Terra, Ambiente e Risorse, University of Napoli Federico II, via Cintia 21, 80126 Napoli, Italy., Geraki K; Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK., Whitehouse MJ; Swedish Museum of Natural History, Stockholm, Sweden., De Min A; Department of Mathematics and Geoscience, University of Trieste, via Weiss 2, 34128 Trieste, Italy., Marzoli A; Dipartimento Territorio e Sistemi Agro-Forestali, University of Padova, 35020 Legnaro, Italy. |
| Abstrakt: |
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. |
