About 250million years ago, the largest life extinction event took place on the earth, and more than 70% of terrestrial life and 90% of marine life disappeared. According to the latest research of the research group of Professor shenyan'an of the University of science and technology of China, the Siberian "super volcano" sprayed a huge amount of sulfur dioxide into the atmosphere at that time, causing the earth's surface to suffer from sulfuric acid rain corrosion and other disasters, which may be the main reason for the mass extinction of terrestrial life. There have been five mass extinctions in the history of the earth, the third of which was the most tragic at the end of the Permian about 250million years ago. Trilobites, ratchets and ancient corals in the sea were extinct, most animals and insects on the land were extinct, and a large number of plants were destroyed, resulting in the loss of coal seams in this period. The cause and mechanism of this mass extinction has always been a major subject of academic concern. (extinct liana monoreticulum fern fossils at the end of Permian. (photo provided by shenyan'an research group) Shen Yan'an research group cooperated with foreign researchers to study the Permian to Triassic strata in Sydney Basin, Australia. Through the measurement and analysis of the underground borehole samples with a length of more than 1000 meters and related strata, the researchers determined the extinction horizon of terrestrial organisms in the Sydney Basin, and thus determined their extinction time. Further high-precision testing of pyrite in relevant strata shows that the sulfur isotope content of pyrite is basically the same before and after the extinction of terrestrial organisms, but it decreases significantly during the extinction period. "Our study found that this anomaly of sulfur isotope was related to the sharp rise of sulfate concentration in the lake water of the Sydney Basin at that time." Dr. limenghan of Shen Yan'an research group said that these sulfates came from atmospheric sedimentation and came from the eruption of Siberian "super volcano". (the extinction horizon at the northern edge of Sydney Basin, Australia (shown by the red line). (photo provided by shenyan'an research group) Siberian "super volcano" has been erupting for hundreds of thousands of years since the end of Permian, triggering a chain reaction of the earth's ecology. This study shows that the sulfur dioxide emitted by the volcano is transformed into sulfate aerosol and diffuses around the world, forming "sulfuric acid rain" to corrode the surface environmental system. In addition, it also produces "ice chamber effect" to cool the world, leading to the mass extinction of terrestrial life. Recently, the international academic journal earth and Planetary Science newsletter published this achievement. (Xinhua News Agency)