The Baikal rift zone is a deep fracture of the earth's crust in the continental part of Eurasia, with a length of about 1,500 km, extending from the south-west to the north-east; he is a divergent border . The central part of the rift is occupied by the fresh, deep-water lake Baikal . Presumably in the rift zone there is a divergence of the earth's crust. In the west of the rift is the Eurasian Plate , and in the east it is bordered by the Amur Plate , moving from the rift towards Japan at a speed of about 4 mm per year. It is characterized by high seismic activity , the presence of volcanoes and hot springs , confined to a system of deep faults. This is the largest “living” tectonic structure of the Eurasian continent.
| UNESCO World Heritage Site | |
| Lake Baikal, located in the Baikal rift zone [* 1] | |
|---|---|
| [* 2] | |
 Lake Baikal | |
| A country | Russia |
| Type of | Natural |
| Criteria | vii, viii, ix, x |
| Link | 754 |
| Region [* 3] | Asia |
| Turning on | 1996 (20th session) |
The crust in the area of the Baikal rift is sophisticated. Hot springs are present both at the bottom of the lake, and on the earth's surface. During the construction of the North Mui tunnel, faults were discovered, through which hot water from the depths of the Earth began to flow in large volumes in the adit, which greatly complicated the construction of the tunnel. No signs of volcanic activity in the immediate vicinity of the shoreline of Lake Baikal were found. In the Quaternary, modern volcanism manifested itself near the lake and was probably associated with the rift zone.
Content
Volcanism of the Baikal Rift Zone
In the Baikal rift zone, modern volcanism of the postglacial period of the Neogene-Quaternary is widely represented. It is represented by lava flows and young, often well-preserved slag cones. South-west of Lake Baikal on the northern side of the Tunkinsky depression on the left bank of the Irkut River is Chersky volcano, as well as fresh traces of the volcanic activity of other underground foci. The volcanic zone on the Udokan plateau, [1] lies about 400 km northeast of the upper edge of the lake; In the Sayan mountains there is a volcanic Oka plateau [2] with Kropotkin and Peretolchin volcanoes and the crater of the Old volcano drowned in a basalt stream [3] . Actually, the Oka volcanic plateau is formed by a basalt stream over 75 km that has poured over a deep fault fracture, which completely or partially filled the valleys of the Khi-Gol and Zhom-Bolok rivers and poured into the valley of the Oka River (Sayanskaya), formerly known as Ok-Khem among the Tuvans, and the Buryats - Aha. Further northwest of the Oka volcanic plateau lies an extensive little-explored volcanic region with a large number of young post-glacial volcanoes. In the southwestern part of the Baikal rift, on the territory of Mongolia, is Lake Hubsugul. The Tunkinsky Basin , located between the Khubsugul and Baikal lakes, is now an unfilled part of the rift - a former lake similar to Baikal and Khubsugul, whose bed is nowadays filled with deluvial and alluvial deposits, as well as products of the Quaternary volcanic activity: spilled basalts and slags. To the southwest of the Tunkinsky volcanic region in the Jida river valley there is another young volcanic region of the same name marked by slag cones. East of Lake Baikal, on the right side of the Vitim River valley, in its upper reaches, volcanic cones and small basalt flows were also found. Thus, in the Baikal rift area there are at least five volcanic regions of the Neogene-Quaternary time:
- Sayansky, including the Oka basalt plateau
- Dzhidinsky
- Tunkinsky with Chersky volcano
- Udokansky
- Vitimsky.
Presumably, part of the volcanic regions of Mongolia and Northern China can also be formed by geophysical processes in the Baikal rift.
The origin of the rift
Some researchers explain the formation of the Baikal rift by the transform fault mechanism, others suggest the presence of a mantle plume under Lake Baikal, while others explain the formation of a basin by passive rifting as a result of a collision between the Eurasian Plate and Hindustan . There are pseudoscientific assumptions that the subsidence of the cavity is associated with the formation of vacuum foci due to the outpouring of basalts on the surface ( Quaternary ). Baikal rift is active. In its vicinity, earthquakes constantly occur.
Along with the East African Rift , Baikal is another example of a divergent border located within the continental crust.
Gallery
The main rift lake - Baikal
Khubsugul Lake is also located in the Baikal Rift, at its southwestern tip
Between Baikal and Khubsugul there is an unfilled section of the rift - the Tunkinsky depression
Layout of the bed of Lake Baikal. Exhibit of the Central Siberian Geological Museum. Akademgorodok
Notes
- ↑ Baikal rift zone : [ eng. ] // Global Volcanism Program . - Smithsonian Institution .
- ↑ Baikal rift zone : [ eng. ] // Global Volcanism Program . - Smithsonian Institution .
- ↑ Baikal rift zone : [ eng. ] // Global Volcanism Program . - Smithsonian Institution .
Literature
- Lyamkin V.F. Ecology and zoogeography of mammals in the intermontane basins of the Baikal rift zone / Ed. ed. Doctor of Biological Sciences A. S. Pleshanov ; Institute of Geography SB RAS . - Irkutsk: Publishing House of the Institute of Geography SB RAS, 2002. - 133 p.
Links
- Baikal Rift System / V.E. Khain // Ankiloz - Banka. - M .: Great Russian Encyclopedia, 2005. - P. 662. - ( Great Russian Encyclopedia : [in 35 vols.] / Ch. Ed. Yu. S. Osipov ; 2004—2017, vol. 2). - ISBN 5-85270-330-3 .