West and East Siberia. Inner Asia

West Siberia consists of the lowland of that name; it extends about 2 500 km north to south and 1 900 km west to east. Its basement is a plate formed in the Palaeozoic, covered by Mesozoic and Cenozoic deposits. Its main minerals are oil, gas and coal. The relief is flat, not above 300 m. Arctic air dominates in winter and temperate air in summer: winter –25…–30 °C, summer about +22 °C, rainfall 480–550 mm. The Ob, Irtysh, Taz and Pur flow into the Arctic Ocean. In the north there are tundra-gley and marshy soils, in the south fertile black soils. East Siberia extends from West Siberia to the Kolyma valley. Its centre is the hard Siberian Platform formed in the Archean; the relief is plateaus — the Central Siberian Plateau (average 400–600 m) and up to 1 701 m in the Putorana Mountains. East Siberia lies in the arctic, subarctic and temperate zones and has a sharply continental climate: –20…–40 °C in winter and +16…+18 °C in summer. At Oymyakon the official record is –67.7 °C (the book’s –71 °C is unofficial). Its rivers are the Yenisei, Lena, Aldan, Kolyma and Vilyuy. Permafrost is widespread in the north; there are arctic desert, tundra and taiga landscapes. Taiga trees are larch, pine, spruce, cedar and Siberian fir; animals include the Arctic fox, wolf, sable and reindeer.