New clues emerge in mass extinction mystery

A mass extinction which occurred 250 million years ago now has a new contributing factor. Published in the journal Science Advances, the research shows that analysis of minerals from China suggest a volcanic winter playing a role.  

The extinction event was the most severe of the the last 500 million years, killing 80 to 90 percent of both marine and terrestrial species. For decades, scientists have looked for clues that would point to the cause of this massive die off. 

Some experts have looked at huge lava flows in Siberia and the subsequent global temperature rise caused by increased atmospheric carbon. This would also lead to lower levels of oxygen in the ocean, suffocating much of the sea life. 

“As we look closer at the geologic record at the time of the great extinction, we are finding that the end-Permian global environmental disaster may have had multiple causes among marine and non-marine species,” said study co-author Michael Rampino, professor at New York University.

The research was carried out by dozens of collaborating scientists from institutions the world over looking for potential causes of the extinction. They found mineral deposits in the southern part of China – especially copper and mercury. The ages of these deposits coincide with the extinction events in terrestrial areas. These deposits were covered with layers of ash from a local volcanic eruption. 

“Sulfuric acid atmospheric aerosols produced by the eruptions may have been the cause of rapid global cooling of several degrees, prior to the severe warming seen across the end-Permian mass-extinction interval,” said Professor Rampino. 

The research suggests that volcanic eruptions in Siberia alone are not responsible for the global extinction. Regardless, these newly discovered eruptions in China likely played an important role. 

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By Zach Fitzner, Earth.com Staff Writer