Geologists uncover new clues about largest mass extinction ever

A new study could help explain the driving force behind the largest mass extinction in the history of earth, known as the End-Permian Extinction.

The event, also known as the Great Dying, occurred around 250 million years ago when a massive volcanic eruption in what is today the Russian province of Siberia sent nearly 90 percent of all life right into extinction. Geologists call this eruption the Siberian Flood Basalts, and it ran for almost a million years.

"The scale of this extinction was so incredible that scientists have often wondered what made the Siberian Flood Basalts so much more deadly than other similar eruptions," said Michael Broadley, a postdoctoral researcher at the Centre for Petrographic and Geochemical Research in Vandoeuvre-les-Nancy, France, and lead author of the paper.

The work, which was published in Nature Geoscience, was co-authored by Lawrence (Larry) Taylor, the former director of the Planetary Geosciences Institute at the University of Tennessee, Knoxville. Taylor, whose prolific career at UT spanned 46 years, passed away in September 2017 at age 79.

According to Broadley, "Taylor was instrumental in supplying samples of mantle xenoliths, rock sections of the lithosphere [a section of the planet located between the crust and the mantle] that get captured by the passing magma and erupted to the surface during the volcanic explosion. Taylor also provided advice throughout the study."

Through the analysis of samples, Broadley and his team tried to determine the composition of the lithosphere. They found that before the Siberian Flood Basalts took place, the Siberian lithosphere was heavily loaded with chlorine, bromine, and iodine, all chemical elements from the halogen group. However, these elements seem to have disappeared after the volcanic eruption.

"We concluded that the large reservoir of halogens that was stored in the Siberian lithosphere was sent into the earth's atmosphere during the volcanic explosion, effectively destroying the ozone layer at the time and contributing to the mass extinction," Broadley said.

Research paper

Related Links
University of Tennessee at Knoxville
Explore The Early Earth at TerraDaily.com

Tweet

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only

SpaceDaily Contributor
$5 Billed Once

credit card or paypal

Amber fossils illuminate early antlion evolution
Washington (UPI) Aug 22, 2018
Newly analyzed amber fossils have helped scientists characterize the evolutionary history of myrmeleontiformia, a group of lacewing insects that includes antlions and is distinguished by predatory larvae and unusual morphologies. Because the larvae of antlions and their relatives fail to fossilize outside amber inclusions, the fossil record is limited. The newly surveyed Burmese amber fossils, hailing from the mid-Cretaceous, allowed scientists to compare extant and extinct myrmeleontiformia ta ... read more