Could the gigantic asteroid that struck Earth some 66 millions ago triggered massive lava eruptions in India be held responsible for extinction of Dinosaurs?
Last week, April 30th, a team of Geophysicists at UC Berkeley, have come up with a new theory wherein the research team feels that an enormous asteroid triggered volcanic eruptions that resulted in the mass extinction of dinosaur species and ushered in the age of mammals. Further they also feel that the the massive eruptions of Lava in India which is known as the Deccan Traps is a result of the impact of this asteroid.
Researchers added that a massive asteroid banged into the ocean off Mexico some 66 million years ago “rang the Earth like a bell” triggered enormous volcanic eruptions around the globe was the main cause of disaster and extinction of many species. They further argued that the impact was likely responsible for triggering the massive eruptions of lava in India that is now referred to as the Deccan Traps. The researchers have elucidated a close coincidence between the Deccan Traps eruptions and the impact. This theory, whether asteroid was the sole cause of the end-Cretaceous mass extinction, has always cast doubt.
Team leader, Mark Richards, from the University of California, Berkeley said: “If you try to explain why the largest impact we know of in the last billion years happened within 100,000 years of these massive lava flows at Deccan, the chances of that occurring at random are minuscule.”
Researchers, further said that the flow of Deccan lava had begun before the asteroid banged Earth however it was erupted for several thousand years after re-ignition which probably led of discharge of extensive amounts of carbon dioxide and other noxious disastrous gases in the atmosphere. It is still not clear if these climatic and environmental changes contributed to the demise of life on Earth at the end of the age of Dinosaurs.
Richards further quoted : “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’.” By mentioning ‘forams’ he was actually referring to the tiny sea creatures called foraminifera. Researchers found that the foraminifera species were larger and more diverse during the end of Cretaceous period and comparatively most of the foraminifera disappeared from the fossil records almost overnight and the surviving species at beginning of the Tertiary period seems to have become smaller in their shapes.
Way back in 1989 Richards had proposed that plumes of hot rock referred to as “plume heads” rise through Earth’s mantle every 20-30 million years which is responsible for the huge lava flows known as “flood basalts” like the Deccan Traps. He realized that the last four or six mass extinctions seems to be concurrent with these massive eruptions. Further research on the Deccan eruptions confirmed this theory of Richards.
Michael Manga, part of the team, demonstrated that volcanic eruptions can also be triggered by seismic events like large earthquakes. The asteroid impact that is being referred here must have generated a magnitude equal to 9 or larger earthquake everywhere on the Earth which was sufficient to ignite the Deccan flood basalts including the mid ocean ridges and other places on the earth. He said:”It’s inconceivable that the impact could have melted a whole lot of rock away from the impact site itself, but if you had a system that already had magma and you gave it a little extra kick, it could produce a big eruption.”
After visiting India in 2014 for further study on the Deccan samples, Richard and his team ultimately found that as per the geological evidences the Deccan terraces indicate a period of quiescence prior to the asteroid impact. Hence Richard ultimately concluded that: “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.”
So it was ultimately concluded that the asteroid impact not only killed the Dinosaur species 66 millions ago but it also stirred enormous lava flow in India, resulting in the Deccan Traps.
