Home » SCIENCE » Did dinosaur-killing asteroid also trigger largest lava flow as evident in Mahabaleshwar?

Did dinosaur-killing asteroid also trigger largest lava flow as evident in Mahabaleshwar?

The asteroid that slammed into the ocean off Mexico 66 million years ago and killed off the dinosaurs could have triggered devastating volcanic eruptions on earth leading to its pinnacle virtually eroding entire life on earth, said a team of UC Berkeley geophysicists.

Mark Richards

Mark Richards sampling a weathered zone between two lava flows of the Deccan Traps, near the town of Mahabeleshwar, India. These zones, locally called “red boles,” may represent periods of time elapsed between the eruption of successive gigantic lava flows. (Paul Renne photo)

Interestingly, the impact on India was immense, according to the researchers, known as the Deccan Traps, explaining the end-Cretaceous mass extinction. Mark Richards, UC Berkeley professor of earth and planetary science, said: “It’s not a very credible coincidence.”

Richards and his team showcased a weathered zone between two lava flows of the Deccan Traps, near the town of Mahabeleshwar, India. These zones, locally called “red boles,” may represent periods of time elapsed between the eruption of successive gigantic lava flows, said the researchers in their paper published in The Geological Society of America Bulletin.

The Deccan lava flows probably spewed immense amounts of carbon dioxide and other noxious gases perhaps causing the demise of most of life on Earth at the end of the Age of Dinosaurs, Richards said but quickly added that more research is required to ascertain it.

“This connection between the impact and the Deccan lava flows is a great story and might even be true, but it doesn’t yet take us closer to understanding what actually killed the dinosaurs and the ‘forams,’” he said, referring to tiny sea creatures called foraminifera, many of which disappeared from the fossil record virtually overnight at the boundary between the Cretaceous and Tertiary periods, called the KT boundary.

The disappearance of the landscape-dominating dinosaurs is widely credited with ushering in the age of mammals, eventually including humans.

Richards calculates that the asteroid that created the Chicxulub crater might have generated the equivalent of a magnitude 9 or larger earthquake everywhere on Earth, sufficient to ignite the Deccan flood basalts and perhaps eruptions many places around the globe, including at mid-ocean ridges.

Richards and  his team along with Deccan volcanology experts Steven Self and Loÿc Vanderkluysen, visited India in April 2014 to obtain lava samples for dating, and noticed that there are pronounced weathering surfaces, or terraces, marking the onset of the huge Wai subgroup flows.

Geological evidence suggests that these terraces may signal a period of quiescence in Deccan volcanism prior to the Chicxulub impact. Apparently never before noticed, these terraces are part of the western Ghats, a mountain chain named after the Sanskrit word for steps.

Western Ghats, India
Photograph of part of the main stack of 66 million year old Deccan Traps lava flows near the city of Mahabaleshwar, India. The entire volume of the Deccan Traps could have covered an area as large as the state of California in a mile deep pile of lava flows.(Mark Richards photo)

“This was an existing massive volcanic system that had been there probably several million years, and the impact gave this thing a shake and it mobilized a huge amount of magma over a short amount of time,” Richards said.

“The beauty of this theory is that it is very testable, because it predicts that you should have the impact and the beginning of the extinction, and within 100,000 years or so you should have these massive eruptions coming out, which is about how long it might take for the magma to reach the surface,” he added.

 

 

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