Siberian “super volcano”caused 250 million year old extinction of life on land
About 250 million years ago, one of the largest extinctions of life on Earth took place, with more than 70% of terrestrial life and 90% of marine life disappearing. The latest study by Professor Shen Yan’an’s group at the University of Science and Technology of China concluded that the Siberian “super volcano” spewed huge amounts of sulfur dioxide into the atmosphere, causing the Earth’s surface layer to suffer from sulfuric acid rain corrosion and other disasters, which may be the main reason for the mass extinction of life on land.
Five mass extinctions have occurred in the history of the Earth, with the third one at the end of the Permian period about 250 million years ago being the most tragic. Trilobites, echinoderms, and ancient corals in the oceans became extinct, most animals and insects on land became extinct, and the mass extinction of plants left the coal seams missing during that period. The causes and mechanisms of this mass extinction of life have been a major topic of academic interest.
Shen Yanan’s group collaborated with foreign researchers to study the Permian to Triassic stratigraphy of the Sydney Basin, Australia. By measuring and analyzing more than 1000 meters of subsurface borehole samples and related stratigraphic layers, the researchers determined the extinction of terrestrial organisms in the Sydney Basin, and thus determined the time of their extinction.
Further high-precision testing of pyrite from the associated strata revealed that the sulfur isotope content of pyrite was essentially the same before and after the extinction of terrestrial organisms, except for a significant decrease during the extinction period.
“Our study found that this anomaly in sulfur isotopes was related to the dramatic increase in sulfate concentration in the lake water of the Sydney Basin at that time.” Dr. Menghan Li of Yanan Shen’s group said that these sulfates came from atmospheric deposition and originated from the Siberian “super volcano” eruption.