Pechora Coal Basin

the second largest source, after the Donets Coal Basin, of coking coals in the European USSR. The Pechora Coal Basin is located on the western slope of the Northern Urals and the Pai-Khoi, extending from the middle course of the Pechora River in the south to the Barents Sea in the north and the Chernyshev Mountains in the west. The basin is in the Komi ASSR and the Nenets National Okrug of Arkhangel’sk Oblast. The total area is about 90,000 sq km, and the total geological reserves are estimated at 344.5 billion tons.

The first information on the discovery of coal in the Pechora Coal Basin dates back to 1828. In 1919, V. Ia. Popov, a hunter, reported finding coal on the Vorkuta River. From 1924 to 1926, Professor A. A. Chernov directed geological expeditions in which major deposits of energy coal in the region were discovered. Exploration directed by geologist G. A. Chernov in 1930 and 1931 resulted in the discovery of coking coals. Coal mining began in 1934 and developed further after completion of the Pechora Railroad in 1942.

The eastern part of the Pechora Coal Basin is included in the Cisuralic foredeep, which to the west gradually becomes the Pechora syneclise. The structure of the basin is marked by an alternation of large, broad complex syneclises (Karskaia, Koro-taikhinskaia, and Usinskaia) with narrow anticlines that divide them (the Chernyshev Mountains, the Chernov rises, the Pai-Khoi anticlinorium).

The Pechora Coal Basin is composed primarily of Paleozoic beds, with a total thickness of 12–15 km. Coal-bearing Permian beds, with thicknesses ranging from 2 km in the southwest to 7 km in the northeast, lie transgressively on Carboniferous marine beds and are covered by a thin outwash of slightly coal-bearing Triassic formations (the Khey-yagan series). The beds are divided into the Iun’iagianskaia, Vorkuta (Lekvorkutskaia and Inta suites), and Pechora series. The Iun’iagianskaia series and the Lekvorkutskaia suite belong to the Lower Permian, while the Inta suite and Pechora series belong to the Upper Permian.

Nine geological-industrial regions are identified based on structural characteristics and coal content. Of these the best studied and most developed are the Vorkuta, Inta, Khal’mer-Iu and Vorga-Shor regions. The number and total thickness of seams (more than 0.5 m) decrease steadily from the northeast to the southwest, from 86 seams in the Khal’mer-Iu region to 74 in the Vorkuta region and 42 in the Inta region. Thin seams (to 1.3 m) and medium-sized seams (1.3–3.5 m) predominate; thick seams (up to 32 m) are encountered rarely and have complex structures (Rogovskoe deposit). The greatest coal content (eight to 14 working coal seams) is observed in the middle and upper parts of the Vorkuta series, in the Rudnitskaia member and the Inta suite. Humic coals range from lustrous to dull, and by degree of metamorphism they represent a complete genetic series. Close to the Urals and the Pai-Khoi there are anthracites, semianthracites, and short-flame coals. These are steadily replaced westward by narrow zones of coals of grades LS (lean-sintering), C (coking), M (metabituminous), and G (gas) and by a broader zone of LF-grade (long-flame) coals. Brown coals predominate in the west. The moisture content ranges from 6 percent in grade M and C coals to 11 percent in grade G and LF coals. Ash content varies from 9 to 40 percent, and phosphorus content from 0.1 to 0.2 percent. The average combustion heat is 30–36 megajoules per kg (7,200–8,600 kilocalories per kg). For working fuel the combustion heat is 18–26 megajoules per kg (4,300–6,340 kilocalories per kg). The best quality coals, which are valuable raw material for obtaining metallurgical and casting coke, are found in the Rudnitskaia member; the other subdivisions contain energy coal. Permafrost and artesian aquifers make mining conditions difficult; the mining shafts contain gas. Coal production in the Pechora basin was 273,000 tons in 1940, 17.56 million ton in 1960, and 22.6 million tons in 1972. The coals are primarily used for coking at the Cherpovets Metallurgical Plant in Vologda Oblast, for various industries in Leningrad, and for railroad transport. The cities of Vorkuta and Inta have developed and have flourished in the Pechora Coal Basin.