Variation of coal quantity accumulated in the Mississippian to Pennsylvanian coal seams (Upper Silesia and Lublin Coal basins, Poland) : a reflection of changes in climate and CO2 availability

Many coal seams of varied thickness and aerial extent occur in the Upper Silesia and Lublin basins within Mississippian and Pennsylvanian coal-bearing deposits. Well-documented data on coal quantity in the seams identified allows visualization of their variation within the stratigraphic succession and analysis of the time-dependent coal accumulation process. Some characteristic features of this variation were observed. Coal seams of the Mississippian age (Serpukhovian, Paralic Series), formed within a near-shore environment, most often constitute small resources. There were only two intervals of increased coal accumulation in seams of >100 million tons, in the lower and uppermost parts of the Paralic Series. Within the Pennsylvanian coal-bearing succession of terrestrial fluvio-lacustrine origin, a specific, wave-like pattern of seam resource variations and four intervals of increased coal accumulation are observed. In the Lublin Coal Basin, the Lublin Beds only, deposited during the Late Bashkirian, are coal-bearing, in which a bell-shaped pattern of seam resource variation in the stratigraphic succession is observed. The location of enhanced coal accumulation events in the stratigraphic succession suggests their repetition at ~1–4 My intervals. The characteristic features of the quantitative variation in these coal seams may be correlated with glacial-interglacial and climate humidity changes, and interpreted as a response to variable volcanogenic CO2 supply.