Soil development in the coal fire environment: a case of Upper Silesian waste heaps

Soil development in burning coal-mining waste heaps is a rarely addressed phenomenon, especially in Poland and in relation to pyrometamorphic substrates. Eight samples were collected from 5 heaps, four of them obtained from Europe‘s highest “Szarlota” heap located in Rydułtowy. Traces of pedogenesis were observed in both thermally changed (pyrometamorphic) and megascopically unchanged substrates. Grain size distribution is variable, with the finest silt being most clearly associated with distinct, though modest, trace element (TE) enrichment, primarily of Sb, As and Pb, and Ba and Cu. Slight variations in soil mineralogy occur even in samples derived from various parts of the “Szarlota” heap. Goethite, however, is a frequent component in most samples studied; it is an important pedogenesis factor in the soils studied and seems to be correlated with salinity. To some extent, it also influences TE composition. Relatively invariable pH, moderate TE and nutrient contents, and a lack of Alw allows vegetation growth at most of the locations studied.