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TOMSK, Aug 13 – RIA Tomsk. Scientists of Tomsk State University (TSU) are studying the ancient igneous rocks of the Eastern Sayan to find out what critical climatic events led to the mass extinction of animals more than 400 million years ago - at the end of the Ordovician Period, the press service of the university said on Tuesday.
The press service clarifies that the employees of the TSU Faculty of Geology and Geography with colleagues from Institute of Geology and Mineralogy of the Siberian Branch of the RAS and Insitute of geology Komi SC UB RAS conduct a joint expedition to Mongolia. In the southern spurs of the Eastern Sayan researchers take samples of ancient igneous rocks. In them "recorded" the history of the Earth and those climatic changes that occurred on the planet in the distant past.
"There is a wealth of evidence that indicates a direct relationship between sudden changes in the environment and magmatic processes, including the eruption of ancient supervolcanoes. For four of the five largest extinctions this relationship has already been proven. For the fifth, which happened at the end of the Ordovician Period, when it died 85% of all living things, the exact cause has not yet been established", - is said in the report.
Scientists are finding out whether there is a relationship between the formations of large igneous provinces and the climate catastrophe that happened on Earth about 440 million years ago. They want to extract the necessary information from zircons - one of the very first minerals formed on our planet.
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“The objects of interest to us are located in the south of the Great Lakes basin and in Prikhubsugul, in the southern spurs of the Eastern Sayan Mountains. We plan to bring rock samples from various massifs and complexes, including samples of more than 10 kilograms - for the extraction of geochronometer minerals and their dating using modern equipment of the laboratory of geochronology and geodynamics", - the employee of TSU Alexey Semiryakov is quoted in the message.
According to the press service, geologists will “read” the information using a unique installation for radioisotope dating conducting. This is the most accurate method for determining the age of objects in hundreds of millions and even billions of years. The analysis will also help to identify isotopic changes and geochemical anomalies which carry information about the climatic effects of the past.
"The analysis of the samples will help to find out how large the erupted provinces are involved in the mass extinction during the Ordovician Period. To get the full picture, we will conduct research of samples taken during the expeditions to Mongolia, Tuva, to the territory of North and Central Asia", - the research supervisor of the TSU Laboratory of Geochronology and Geodynamics Richard Ernst is quoted in the message.