Ekibastuz Coal Basin

a coal basin located in Baianul Raion, Pavlodar Oblast, Kazakh SSR. The Pavlodar-Tselinograd main railroad line passes near the basin, as do the Irtysh-Kara-ganda Canal and the Pavlodar-Karaganda Highway. The basin is confined to an enclosed depression covering an area of 155 sq km. It is 24 km wide and has a maximum width of 8.5 km. The total estimated geological reserves of coal are 10 billion tons.

The Ekibastuz Coal Basin was discovered in 1876. However, intensive geological exploration was begun only in 1940, which established the possibility of mining the coal by the open-pit method. Construction of the first coal pit was begun in 1948; it was put into operation in 1954.

The margin and basement of the basin consist of Lower Devonian volcanogenic formations. The coal-bearing formation of the Lower (Viséan and Namurian) and Middle Carboniferous and the underlying marine sediments of the Middle and Upper Devonian and Lower (Tournaisian) Carboniferous constitute a brachysyncline, bounded on the northeast and southwest by major longitudinal faults. Rocks along the limbs of the brachysyncline are gently bedded (9°–30° degrees), while those in the areas close to the faults are steeply bedded (some even overturned) and complicated by fractures. The lower, unproductive, complex of sedimentary rocks is about 1,000 m thick; the upper, productive, complex reaches a thickness of 1,690 m. The lowermost strata of the coal-bearing formation (the Akkudukian and Ashliarikian suites) contain interlayers of carbonaceous rocks and coals in the upper horizons. The Karagandian suite (to 600 m) and the Supra-karagandian suite (to 390 m), which encompass the central part of the brachysyncline over an area of 74 sq km, contain 11 and nine coal seams, respectively. Three thick, contiguous seams of the Karagandian suite are industrially important: the lower, or third, seam, which is 84–108 m thick (average, 95 m); the middle, or second, seam, which is 33–43 m thick (average, 38 m); and the upper, or first seam, which is 20–25 m thick (average, 22.5 m). Coal seams up to 1.5 m thick alternate with interlayers of sandy-clayey and carbonaceous rocks ranging in thickness from fractions of a centimeter to a few meters. The first and second seams have a more compact structure.

The coals are hard humus coals, with an industrial grade of WCa (weak caking). They have a high ash content, which increases with increasing depth in the coal-bearing cross section and are difficult to enrich. The ash content of coal concentrates with a density of less than 1.8 g/cm³ ranges from 28 percent (first seam) to 35 percent (third seam).

All the coals in the basin, down to their full depth, are suitable for open-pit mining. Coal extraction in 1975 amounted to 45.8 million tons. The total capacity of the coal sections in 1976 reached 52 million tons. The coals are used as fuel at large power plants (pulverized coal burning) in the Middle and Southern Urals and in Kazakhstan. The Ekibastuz Coal Basin is a key part of the Pavlodar-Ekibastuz Territorial-Production Complex.