250 million years ago, the land life was extinct. Is the "main criminal"?

About 25 million years ago, a largest life extinction occurred on the earth, more than 70%of land creatures and 90%of marine life disappeared. Professor Shen Yanan's research group of Professor Shen Yan'an of China University believes that at that time, the "super volcano" of Siberia sprayed huge amounts of sulfur dioxide into the atmosphere, causing disasters such as sulfuric acid -type rainy corrosion of the earth's surface, which may be the main reason for the extinction of land life.

Five great extinction occurred in the history of the earth, about the third time at the end of the two stacks of about 250 million years ago. Three -leafworm, spiny fish, ancient corals, etc. in the ocean, most animals and insects on land are extinct, and a large number of plants have lack of coal seams in the period. The reasons and mechanisms of this life extinction have always been a major issue for the academic circles.

The ending of the vine plant single -net sheep tooth fossil. (Photo confession of Shen Yanan's research group)

The Shen Yan'an research group and foreign researchers cooperated to study the Trifloat -to Triplatitude of the Sydney Basin in Australia. By surveying and analysis of underground drilling samples and related strata with a length of more than 1,000 meters, researchers have determined the layers of land organisms in the Sydney basin, thereby determining their extinction time.

Further conducting high -precision tests on the related strata of pyromics found that before and after terrestrial creature extinction, the sulfur isotope content of pyrite is basically the same, and the exterior period is significantly reduced.

"Our research found that this abnormality of sulfur equivalent is related to the sharp increase in sulfate concentration in the lake in the Sydney basin at that time." Dr. Li Menghan, Shen Yanan's research group, said that these sulfate came from the atmosphere and originated from the "super volcano" of Siberia. Run.

The biological extinction layer of the northern edge of the Sydney Basin in Australia (shown in the red line). (Photo confession of Shen Yanan's research group)

Siberia's "Super Volcano" has continued to erupt for hundreds of thousands of years from the end of the two -stack, which has caused a chain reaction of the earth's ecology. This study shows that the sulfur dioxide from the volcano transformed into sulfate gas solids in the world, forming a "sulfuric acid rain" corrosion of the surface environment system. In addition, the "ice room effect" has cooled the world, which leads to great extinction of land life.

A few days ago, the international academic journal "Earth and Planet Science Communications" published the result. (Reporter Xu Haitao, Dawei)

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