Deccan Volcanic Activity Linked to Dinosaur Mass Extinction Event
A groundbreaking study has revealed that volcanic eruptions in India's Deccan Plateau played a dominant role in the mass extinction event that wiped out non-avian dinosaurs and numerous other species approximately 66 million years ago. Published in The Geological Society of America Bulletin, the research provides new insights into the environmental toxicity caused by these eruptions.
Timing and Scale of Eruptions
The analysis indicates that about 70% of the volcanic eruptions in the Deccan Plateau occurred during the terminal Maastrichtian era, which represents the final few hundred thousand years of the Cretaceous Period. This period immediately precedes the Cretaceous-Paleogene boundary, a critical marker for the mass extinction event.
Researchers from the Advanced Centre for Water Resources Development and Management and Fergusson College in Pune computed that 1.5 million cubic kilometres of Deccan flood basalts erupted over a span of 700,000 years, from 66.31 to 65.73 million years ago. This timeframe straddles the Cretaceous-Paleogene boundary, highlighting the intense volcanic activity during this epoch.
Toxic Degassing and Environmental Impact
The study emphasizes that the toxic degassing from these lavas, particularly in the 300,000 years leading up to the Cretaceous-Paleogene boundary, set the stage for the mass extinction. During and after eruptions, hazardous gases and aerosols were released into the atmosphere through the degassing process, contributing to severe environmental crises.
By coupling geochronology with previously published paleomagnetic and paleontological data from sediments associated with the Deccan volcanic activity, the researchers concluded that the late Maastrichtian flood basalt volcanism was significantly larger in magnitude compared to the Danian volcanism in the same region.
Clarifying Historical Ambiguities
The findings address long-standing ambiguities regarding the environmental impact of volcanism during the terminal Cretaceous times. The authors state that earlier projections of the temporal distribution of Deccan lavas were open to revision, and this new analysis solidifies the link between volcanic activity and the mass extinction.
We conclude that the late Maastrichtian Deccan volcanism was the dominant contributor to the environmental crisis resulting in the Terminal Cretaceous Mass Extinction, the researchers wrote. This event not only eradicated non-avian dinosaurs but also pterosaurs and many marine organisms, reshaping Earth's biological landscape.
The study underscores the profound effects of volcanic activity on global ecosystems and provides a clearer understanding of one of history's most catastrophic extinction events.
