Lena-Angara Plateau

The Lena-Angara Plateau (Лено-Ангарское плато), is a plateau in Siberia. Administratively it is in the Irkutsk Oblast, Russian Federation. The plateau is named after the Lena and Angara rivers, of which it forms the watershed. Rivers on the plateau flow mostly in a south–north direction.

The plateau has rich mining areas where iron and copper ores are extracted, as well as rock-salt, talc and mica. The Lena-Angara Plateau is mostly sparsely populated. The biggest settlements are Ust-Kut, Kirensk, Zheleznogorsk-Ilimsky, as well as the villages of Zhigalovo and Kachug. The Bratsk Reservoir is located in the plateau area.

Geography
The Lena-Angara Plateau rises in the middle part of Irkutsk Oblast, between the Angara River to the west and the Kirenga River, a tributary of the Lena, to the east. To the northwest it is bound by the Angara Range, to the south by the Angara valley, to the southeast by the Primorsky Range, and to the east by the Baikal Range, beyond which lies Lake Baikal.

To the north the Lena-Angara Plateau merges with the Central Siberian Plateau. It extends roughly for over 600 km with a maximum width of 380 km. The average height of the plateau surface is 1100 m in the south, decreasing to an average of 500 m in the north. Mountaintops are flat and elevations moderate; the highest point is the Namai, a 1464 m high summit. This same mountain, however, is marked as a 4852 ft peak in the E-8 sheet of the Defense Mapping Agency Navigation charts. The same peak is shown as a 1509 m summit in the N-48 sheet of the Soviet Topographic Map.

Hydrography
The plateau is dissected by deep river valleys with average depths ranging between 600 m and 200 m. The upper course of river Lena crosses the plateau roughly from south to north. Its tributaries Kirenga, Ilga, Tutura, Tayura and Kuta join it in the plateau area. The plateau also includes highly developed karst forms such as the Botovskaya Cave.

Flora
There are taiga forests made up mostly of larch, spruce and Siberian pine in the higher areas and larch in the river valleys.