Tunkin Depression

The depression consists of a number of basins and is covered by alluvial sediments of the Irkut River.

In the Cenozoic, rifting proper commenced generating basins that were filled by sediments and basaltic volcanism.

The causes of the rifting are unclear and may involve either tectonic effects of the India-Asia collision, mantle plumes and asthenospheric processes.

[2] The volcanic field consists of numerous cinder cones and lava flows west of the western tip of Lake Baikal.

The largest number of individual volcanoes is found close to the town of Tunka and is named the Khobok group.