Baikal Rift Zone

A series of basins form along the zone for more than 2,000 kilometres (1,200 mi), creating a rift valley.

[16] The area was originally characterized by Precambrian and Paleozoic northeast-southwest fold and thrust belts.

The late Cretaceous is also the age of sedimentary rocks in some basins, and the same series lasted into the Eocene.

[17] Rifting resumed beginning in the Oligocene, and is commonly held to have increased since the middle Pliocene,[6] causing the formation of basins in the form of grabens.

Outside of the grabens basalt volcanics erupted from either end of the rift system during the uplift.

Finally there is the modern rift unit of fluvial, glacial, and deltaic sediments.

[17] Examining Pliocene and younger sediments reveals sands, argillites, and silts, indicating lacustrine deposition.

[6] The first seismic station in the region was opened in Irkutsk in 1901, which began instrumental observations.

[5] Due to the distance from active plate boundaries, the driving forces of the rift are unknown; however, possibilities include the subduction of the Pacific Plate and the collision of the Indian subcontinent with Eurasia.