Basin evolution and coal geology of the Donets Basin (Ukraine, Russia): An overview

Abstract

The Donets Basin is a major coal-mining district in eastern Ukraine and adjacent portions of Russia. It comprises the Donbas Foldbelt, which is the uplifted and compressionally deformed part of the Pripyat–Dniepr–Donets (PDD) Basin, and the significantly less deformed Western Donbas region. The PDD Basin is a Late Devonian rift structure located within the East European Craton. Thick coal-measures formed during the post-rift stage of the basin in Serpukhovian to Moscovian times, when about 130 seams, each with a thickness over 0.45 m, have been deposited.

Early Serpukhovian coal accumulated in a relatively narrow shore-zone. It is rich in inertinite and liptinite and very low in ash. Bashkirian and Moscovian coal have a significantly wider lateral extension and are generally rich in vitrinite. Bashkirian and Moscovian coal seams usually have high ash yields (12–18%) and high sulfur contents (2.5–3.5%), but these data vary significantly depending on peat facies.

Coal rank ranges from subbituminous to anthracite and is mainly controlled by the depth of the seams and the heat flow during maximum (Permian) burial. Permo-Triassic thermal events locally overprinted the resulting coalification pattern. Coked coal occurs at the contact to presumed Permian sills and dikes southwest of Donetsk. Deep Permian burial was followed by major Permian and Mesozoic uplift events.

The Donets Basin hosts proven reserves in the order of 60 Gt at the exploitable depth. The thickness of coal seams currently mined is in the range of 0.6 to 2.5 m. Production during 2009 was 68.7 Mt in the Ukrainian and 4.9 Mt in the Russian part of the basin. Coal mines in the Donets Basin are among the gassiest in the world. The average methane content of coal is 14.7 m³/t, but numerous seams have significantly higher gas content. The high methane content presents a severe mine safety problem. On the other hand, it represents also a high potential for coal mine bed methane projects. Emissions of coal gas released by mining and related structurally induced underground hazards (coal and gas outbursts) are a major problem for safe and efficient coal exploitation in the basin.