Hypotheses about the origin of Baikal
One of the first to explain the appearance of Lake Baikal was put forward by the participants of the expedition of the St. Petersburg Academy of Sciences in late 18th century. German researchers Johann Georgi and Peter Pallas, who collaborated with the Academy at the invitation of Catherine the Second, believed that the depression of the lake was formed after the tectonic failure of part of the land, which was caused by natural cataclysm.
The cause of the failure, Georgi believed, was a powerful earthquake, which could well affect even the course of local rivers.
A century later, political exile Jan Czerski, a Pole by descent, put forward his own version of Baikal’s origin. He was based on his observations and surveys that he made in the course of his travels around the lake. The talented scientist suggested that the hollows and mountains around it arose after the Earth’s crust was slowly compressed horizontally.
Since that time, very many scientists have put forward their own arguments in favor of a hypothesis, which often differed only in small details. The closest to the modern scientific understanding of the problem of education of Baikal came V.A. Obruchev. In his opinion, Baikal formed together with Siberia’s mountain system.
Obruchev believed that the depression, which subsequently became a lake, arose after subsidence of land over two rupture surfaces that followed in a vertical direction.
Modern view on the problem of occurrence of Baikal
Advance in the study of the question of the origin of the Baikal basin allowed only scientific achievements of the last century. When the existence of a global crustal fault system was discovered by geologists and geophysicists, it was revealed that the appearance of Baikal became part of the processes that took place on a planet-wide scale. Researchers found that several depressions on Earth have a nature similar to Baikal. An example is Lake Tanganyika and Nyasa, as well as the Red Sea.
According to scientists, the tectonic processes that led to the formation of the lake began more than 30 million years ago.
The Baikal depression is considered today to be the central part of the rift of the same name, that is, the depression formed after the shear of the Earth’s crust. The length of the rift is more than two thousand kilometers. The depression is located between two powerful lithospheric plates. At first, geophysicists believed that the lake hole had resulted from the collision of these plates, but then it was assumed that the temperature of the mantle had been added to their interaction, $ located under the Baikal depression.