Coalfield(redirected from coalfields)
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an area of considerable size or with substantial coal reserves where coal-bearing formations are distributed continuously or in island-like patterns. The formation of a coalfield is associated with the development of crustal structures, such as syneclises, foredeeps, and inherited troughs.
The Russian term for coalfield, ugol’nyi bassein, is also applied to the special type of coalfield known as a coal basin, which is a coalfield with a synclinal basin structure. As a result of the existence of the cognate terms bassein and “basin, ” translations from Russian into English often refer to coalfields as “basins, ” even when the fields are not basins in the strict sense.
In the USSR coalfields are usually divided into geological-industrial regions (geologopromyshlennye raiony). The demarcation of the regions is based on the boundaries of administrative areas, on past experience in working the coalfield, and on characteristics of the geologic structure of the various parts of the field. The coalfield known as the Pechora Coal Basin, for example, has nine regions, of which the Vorkuta, Inta, and Khal’mer-Iu are particularly well-known. Within a geological-industrial region coal deposits are usually identified. The geological boundaries of coalfields and coal deposits are formed by the outlines of the genetic thinning out of the coal-bearing formajions and by faults along which coal deposits have been brought into contact with non-coal-bearing rocks. Where the coal-bearing formations extend continuously over a substantial area, consideration is given to the structural separateness of the occurrence of coal beds, sharp decreases in the coal content of cross sections, and other factors. In establishing the boundaries of coal deposits, attention is also given to factors determining the choice of reasonable boundaries for the operation of mining enterprises—for example, the depths at which the deposits are workable and the nature of the relief and surface features (such as large bodies of water, streams, and industrial structures) under which protective pillars must be used.
The term “coal-bearing area” (uglenosnaia ploshchad’) is applied to little-studied coalfields where the coal density has been determined for certain sections but the genetic unity and industrial significance of the coal density has not been sufficiently well established.
There are about 30 known coalfields in the USSR and more than 50 known deposits that lie outside the boundaries of coalfields. The most important fields are the Donets, Kuznetsk, Pechora, and Karaganda, which possess large reserves of hard coals (including coking coals and other varieties that are valuable for industrial use) and have economically advantageous locations. Another coalfield of great importance is the Southern Yakut, which is undergoing development. It contains hard (coking) coals and is located within the region to be served by the Baikal-Amur Main Line.
Substantial amounts of brown coal used to produce heat and power are supplied by coalfields in the European part of the USSR, in the Urals, in Southern Siberia, and in Kazakhstan; such fields include the Moscow, Dnieper, Cheliabinsk, and Kansk-Achinsk. In addition, sizable quantities of hard coal used for the production of electric power are mined in the Ekibastuz region. These coalfields have thick beds suitable for working in large sections.
Coalfields supplying brown coal that appear promising for the expansion of coal production include the Southern Ural, Ubagan (Turgai), and Maikiuben’ (in Kazakhstan). Fields of great promise with respect to hard (coking) coal include the Ulu Khem in Tuva and the southern part of the Irkutsk. The Taimyr, Lena, Zyrianka, and Tunguska coalfields have great potential, but the exploitation of their deposits is made difficult by the remoteness of the fields from economically developed regions.
A number of isolated coal deposits not associated with coalfields supply coal on a local basis for the production of heat and power. Such deposits are found in the Urals, Georgia, Middle Asia, Transbaikalia, the Far East, and the Northeast. Coal is also produced on a local basis in, for example, the Okhotsk and Amur-Zeia coal-bearing areas in the Far East.
With respect to size of reserves and economic importance, the principal coalfields in Europe outside the USSR are the following: the Ruhr in the Federal Republic of Germany; the Valenciennes in France; the Saar-Lorraine in France and the Federal Republic of Germany; the Campine in Belgium; the South Wales, Yorkshire, Derbyshire, and Lancashire in Great Britain; the Oviedo in Spain; and the Upper Silesian in Poland and Czechoslovakia.
Major coalfields in North America include the Appalachian, Pennsylvania, and Uinta in the USA and the Alberta in Canada.
The most important coalfields in Asia, outside the USSR, are the Zonguldak and Anatolia in Turkey, the Fushun and Huang Ho in China, and the Martapura and Bukitasam in Indonesia.
Important coalfields in Australia include the Great Syncline, New South Wales, and Latrobe Valley.
REFERENCESGeologiia mestorozhdenii uglia i goriuchikh slantsev SSSR, vols. 1–11. Moscow, 1962–73.
Matveev, A. K. Ugol’nye mestorozhdeniia zarubezhnykh stran [vols. 1–4]. Moscow, 1966–74.
K. V. MIRONOV