Selected parameters of coal quality in fault zones of the Upper Silesian Coal Basin (Poland)

The paper presents the changes of coal seams quality near fault zones. Three types of relations have been found. The first one shows an increase of coal quality at the 0.2 m distance from fault surface, as a result of increase of coalification degree. It is assumed that, this type was caused by heat of friction which was rising during faulting. It is revealed as an increase of such parameters as: caking properties, vitrinite reflectance, calorific value and carbon content, as well as the decrease of oxygen, ash, and moisture content. The second type presents differed degree of coal quality decrease. This type was produced due to hypergenic processes. The author found four subtypes of oxidation-type changes of coal quality parameters in fault zones. The first one shows the highest level of hypergenic processes in a coal seam about 1 m off a fault plane. The second presents minor degree of oxidation processes in the coal seam at a smaller distance from the fault. The third one demonstrates minimum oxidation changes of coal quality at a distance of 0.2 m from the fault. The fourth subtype of the oxidation changes of coal quality has been observed only in tectonic breccia and not in the coal seams itself.The third types demonstrates faults which do not show any impact on changes of coal quality parameters. To this type belong faults from SW part of USCB and faults with downthrown up to 20 m.