Professor of Science and Technology of China extinction of life on Earth, a new model

 BEIJING, Hefei February 27 (Xinhua Yang Baoguo Wu Lan) 27, a reporter learned from the China University of Technology, February 22, internationally renowned academic journal Chinese Academy of crust-mantle and Environment Laboratory, largest in the history of the Earth's mass extinction events in the cause of a life made new geochemical evidence.

paleontological record shows that in the past 540 million years of geological history, the earth 5 times total mass extinction event. Which took place in 250 million years ago, before the end-Permian extinction of life represents the life history of the most tragic extinction, killing more than 90% of marine species disappeared and a large land creatures perished. Over the years, Earth scientists around the world caused by the end-Permian mass extinction of life phenomena and study in depth the reasons, the establishment of a number of theories and models. Shen Yan, Professor of the latest research reports new geochemical evidence for the extinction of life made new models, so as to promote the awareness of the reasons for the end-Permian extinction understanding of life.

the National Natural Science Foundation of Outstanding Youth Science Foundation, the Shen Yan, Professor of Zhejiang Meishan section carried out a detailed geochemical studies. Geological age of the section is a Permian-Triassic boundary (about 2.5 million years ago) strata of global standards around the world to determine the precise formation of this time interval should be compared with the Meishan section relative, so called Golden Nail Professor Yan Shen and his colleagues first accurate determination of the Meishan section in a variety of sulfur isotopic composition, the gradual extinction event that started with the sulfur isotopic composition of a staged over time exception. According to the principle of sulfur isotope fractionation and chemical composition of the Permian sea, they believe, is anaerobic seawater sulfur isotopic anomaly (lack of oxygen in sea water) is caused by intermittent upwelling. Evidence indicates that the end-Permian deep ocean waters of oxygen, and in certain areas of the deep ocean concentration of carbon dioxide and hydrogen sulfide (rotten egg smell a smell like toxic gases). When the upwelling of deep water to shallow marine areas, it will cause a mass extinction of marine life.

Yanan Shen found that the sulfur isotopic anomalies, with many species before the mass extinction events is consistent with a significant reduction. Therefore, they contain large amounts of toxic gases made anaerobic intermittent upwelling of water caused a significant reduction of biological species and extinction.

Yanan Shen further explained that the research results show that the end-Permian atmospheric carbon dioxide enrichment, anaerobic intermittent upwelling of water, etc., causing the Earth's surface environment was deteriorating, leading to life's great extinction. This conclusion is of great inspiration to the modern meaning of global change: the rising atmospheric carbon dioxide could lead to oceans of oxygen, under certain conditions will produce a similar end-Permian ocean. If such further deterioration of the marine environment, ecological environment will be catastrophic human destruction.