Siberian natural resources refers to resources found in Russian Siberia, in the North Asian Mainland. The Siberian region is rich in resources, including coal, oil and metal ores. Contribution to Soviet economy Siberia’s contribution to the Soviet economy in percent of national output was given in Soviet statistical yearbooks for 1973 (1940 in brackets) as: Coal 33% (23%), Coking coal 30% (17%), Oil 21% (1.6%), Natural gas 8.5% (from 1.5% in 1950), Electric power output 18% (6.6%), Iron ore 6.9% (1.6%), Pig iron 9.5% (10%), Crude steel 8.3% (10%), Rolled steel 10% (9.1%). But regional breakdowns were omitted in the yearbooks from 1973, except for a few 1975 figures. Energy sources Coal In the important Chelyabinsk coalfields, production rose from 390,000 tonnes in 1925 to 3,519,000 tonnes in 1936. The total production for the East Urals was 8,080,000 tonnes in 1937. Reserves for the following coalfields are shown in millions of tonnes: East Urals: (Triassic lignite): 2,872 Karaganda (Low Carboniferous period, for coking): 52,696 Kuznets (Permian, for coking): 450,658 Minusinsk (Permian): 20,612 Chulym-Yenisei: (Jurassic lignite): 43,000 Kansk: (Jurassic lignite): 42,000 Irkutsk and Transbaikalia (Jurassic): 81,397 Bureya: 26,116 Suchan (for coking): 42,000 Tunguska (low Carboniferous): 400,000 Lena (Mesozoic): 60,000 Kuznetsk Coal Zone The development of the coal fields of Kuznetsk Basin, (sometimes called the "Kuzbass") transformed the Siberian steppe. The south sector of the Trans-Siberian Railway became a great industrial center because of the activity surrounding the coalfields. These ancient reserves of 13,000,000,000 tonnes grew to 450,658,000,000 tonnes. In 1937, the 50 mines in this area produced a total of 17,300,000 tonnes. The coal production of this zone was comparable with that of all of British India, and half of that produced by Japan. Kuznetsk coal was the best in the USSR, with high energy and low sulphur content. The total anthracite reserve was 54 million tonnes; and was used in the Ural-Kuznetsk Metallurgical Combine. Siberia is also the coldest winters to survive, this includes freezing temperature such as -50 degrees. Other coal deposits Another important reserve is at Karaganda near the Magnitogorsk (Magnet City) Higt Ovens. Production in 1937 was 3,937,200 tonnes. Other important coal deposits are: Minusinsk near Chernogorsk, which joins the mining zone of Chulym-Yenisei at the Yenisei river; the Kansk deposits north of Krasnoyarsk; the Irkutsk deposits, which yielded 3,000,000 tonnes from the Cheremkovo mine in 1937; the Lake Baikal deposits; the Lena sector; the Norilsk sector