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Mass extinction 250 million years ago. Scientists have described another potential cause

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What caused the mass extinctions on Earth about 250 million years ago? A team of scientists has identified another factor that could have led to it. An analysis of minerals from southern China revealed that the eruptions of nearby volcanoes caused a phenomenon known as “volcanic winter”.

The mass extinction, which occurred some 250 million years ago, is the largest mass extinction ever observed in the history of life on Earth. 80 to 90 percent of terrestrial and marine species became extinct then.

One of the causes of this process is considered to be climate change, which was caused by prolonged volcanic activity in Siberia. At the turn of the Permian and Triassic, Siberian lava flows were formed, i.e. the largest Phanerozoic (Phanerozoic is a period in the history of the Earth that covers the last 500 million years and continues to this day). As a result of increased volcanism, large amounts of pollutants and sulfur compounds were released into the atmosphere. The access to light was blocked, the oxygenation of ocean waters decreased.

The deposits of minerals from China are another clue

A team of 20 scientists from various universities, including China and the United States, looked at other potential factors that could have caused mass extinctions. The research on the subject was published on November 17 in the journal Science Advances.

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In the southern regions of Chi, scientists discovered deposits of copper, mercury and other minerals that date back to the mass extinction period. Their chemical and isotopic composition suggests that these minerals were strongly influenced by sulfur. They were covered with layers of volcanic ash. According to researchers, it most likely indicates increased eruptions of nearby volcanoes.

“Volcanic winter”

‘The sulfuric acid aerosols that resulted from the eruption may have caused the rapid global cooling that occurred prior to significant warming during the mass extinction period,’ explained geologist Professor Michael Rampino of New York University, one of the authors of the study.

The drastic drop in temperature, which was supposed to be caused by the increased volcanic activity in Siberia, was called “volcanic winter”. According to researchers, he also contributed to the mass extinction of species.

sciencealert.com, eurekalert.com

Main photo source: Shutterstock



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