Asteroid impact may have boosted Deccan volcanism

An asteroid that slammed into the ocean off Mexico 66 million years ago, may have boosted Deccan volcanism triggering more volcanic eruptions, suggests new research.

Analysing Deccan Trap samples taken from the Mahabaleshwar region of Maharashtra, the scientists argue the impact was likely to have triggered most of the immense eruptions of lava in India known as the Deccan Traps.

The research seeks to explain the “uncomfortably close” coincidence between Deccan Traps eruptions and the asteroid impact, which has always cast doubt on the theory that the asteroid was the sole cause behind the disappearance of the dinosaurs from the Earth.

The disappearance of dinosaurs and many other animals around 65 million years ago – a period known as KT boundary – remains one of the big scientific mysteries.

In the past scientists theorised asteroid impact, massive volcanism and a rapid change in earth's climate due to excess carbon dioxide and dust in the atmosphere as possible reasons for the mass extinctions at the KT boundary.

“Whether the volcanism, which was clearly already underway when the impact occurred, would have been catastrophic without being boosted by the impact is a fundamental remaining question,” said Paul Renne, from the University of California, Berkeley and one of the scientists associated with the study.

Renne and his colleagues at Berkeley had proposed how plumes of hot rock, called “plume heads,” rise through Earth’s mantle every 20-30 million years and generate huge lava flows, called flood basalts, like the Deccan Traps.

The last four of the six known mass extinctions of life occurred at the same time as one of these massive eruptions.