The Donbas has one of the largest coal deposits in the world. The proved reserves of class A, B, and C coal were 55.6 billion t in 1977, or 20 percent of the total USSR reserves. The Ukrainian Donbas contained close to 48.1 billion t. In 2000, proved reserves were raised to 57.5 billion t and probable reserves for additional 18.3 billion t. Methane gas reserves associated with the coal deposits were estimated to exceed 2.5 trillion cubic meters.
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