Altai-Sayan folded region

ALTAI-SAYAN FOLDED REGION (RU: Алтае-Саянская складчатая область) is the the region of the Paleozoic folding of the Southern Siberia, which stretches itself near the southern border of the USSR from the basin of the Lake Zaysan at the west to the Lake Baikal at the east.

The folding region has been formed by the systems of the variously oriented ridges with the absolute altitudes from several hundred metres to 4000 metres, and by the valleys, which are dividing them, and are incised by the valleys of the rivers (the upper parts of the Ob and Yenisei rivers). The main mountain structures are: Altai mountains, Mountainous Shoria, Salair ridge, Sayan mountains, Sangilen Highlands, Eastern and Western Tannu-Ola, Kuznetsk Alatau, and others. There correspond to the large intermountain depressions of the relief the Kuznetsk, Minusinsk, and Tuva depressions.

The relief of the Altai-Sayan folded region has formed itself as the result of the activation of the tectonic movements in the Neogene and Quaternary time. The Paleozoic folded structures of the Altai-Sayan folded region continue themselves at the south in China and Mongolia; these structures at the north submerge themselves under the cover of the Mesozoic-Cenozoic of the West Siberian plate, at the east frame the ancient Siberian platform, while nearer to the south proceed into the structures of the Western Transbaikalia, at the west merge with the structures of Kazakhstan of the same age.

The Altai-Sayan folded region has the diverse geological structure, the sharply differing strikes of the folded structures, and their end joints along the deep faults. Here are located the Baikal and Salair (Eastern Sayan, Kuznetsk Alatau, Mountainous Shoria), Caledonian (West Sayan, Southeast Tuva, partially Mountainous Altai), and Hercynian (Ore Altai, Salair) folded systems, and also the large massifs with the pre-Riphean basement (Sangilen, Khamar-Daban). The Altai-Sayan folded region is rich in the minerals. The leading minerals are: the ores of the iron, of the polymetals, of the rare metals, of the manganese, the coal, asbestos, phosphorites, bauxites, table salt.