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How millions of years of volcanic eruption led to the deadliest mass extinctions in Earth's history



About 250 million years ago, nearly 90 percent of Earth's life disappeared in the most vicious mass extinction the world has ever known – the Permian-Triassic extinction or the "Great Dying."

Around the same time, hot rock rose in the mantle, roared, steamed and stuttered in a colossal volcanic eruption that raged for nearly a million years. Researchers have long searched for possible links between this eruption and mass extinction.

Now, a team of geologists in Nature Geoscience believes that they have shown how the wild event could have driven the strange and titanic death. out. Researchers believe the volcano has shaken chemicals into the atmosphere and destroyed the ozone layer, a protective shield that protects our planet from dangerous ultraviolet radiation.

The outbreak occurred in the north of the ancient supercontinent Pangea, which finally broke into the modern continents see today. It took place in present-day Siberia, Russia, a region marked by its violent volcanic history. Today it is known as the Siberian flood basalts or the Siberian traps.

"The extent of this extinction was so incredible that scientists have often wondered what made the Siberian tide basalts so much more lethal than other similar eruptions," Michael Broadley, a postdoctoral fellow at the Center for Petrographic and Geochemical Research in Vandœuvre- lès-Nancy, France, and lead author of the published research, said in a statement.

Broadley and colleagues looked at the lithosphere ̵

1; our crust and upper part of our planet's mantle – for clues to the dramatic history of the region. Team member Lawrence Taylor, a former director of the Planetary Geosciences Institute at the University of Tennessee, who passed away in September 2017, procured a series of rocks once deep in the earth.

"Taylor provided samples of mantle xenoliths, lithospheric strata, which are caught by the passing magma during the volcanic explosion and thrown to the surface," Broadley said. [194559007]  8_28_Lava lake A lake of lava is shown. Volcanic activity could be behind the largest extinction event in Earth's history, scientists have shown. Getty Images

Sophisticated analyzes of these samples showed that this region of the lithosphere was full of halogens, including chlorine, bromine, and iodine. Halogens are chemicals that produce salts when they react with metals.

But after the outbreak, these chemicals were nowhere to be seen. "We came to the conclusion that the large reservoir of halogens stored in the Siberian lithosphere reached the Earth's atmosphere during the volcanic explosion, destroying the ozone layer at that time and contributing to mass extinction," Broadley said.

Rich In terms of Earth's history, Siberia has yielded other incredible scientific discoveries. Earlier this month, scientists found a 40,000-year-old extinct young horse that is almost perfectly preserved in the region's permafrost.


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