Quiz: Remember the definition of mal de mer?
one of the largest producing coalfields of Russia, in Kemerovo oblast (province), south-central Russia. It lies in the basin of the Tom River between the Kuznetsk Alatau and Salair mountain ranges. The coalfield was first discovered in 1721. It covers about 10,000 square miles (26,000 square km) and contains proved, minable reserves of 725,000,000 tons, distinguished by thickness of seam and concentration. There are three main coal-bearing series; the Balakhonka Series, the oldest, contains 30-35 workable seams, some up to 50 feet (15 m) thick and in places reaching 130 feet (40 m). These seams contain anthracite and the richest coking and steam coals of the Kuznetsk Basin. Kuznetsk Basin coal is generally of high quality, with less than 1 percent sulfur but sometimes with a rather high ash content, necessitating pithead enrichment. About one-quarter of it is mined by open-cast methods, chiefly in the north; as a result, production costs are low, especially in comparison with the Donets Basin coalfield, another of the major coal producers