The evaluation of threats connected with the presence of methane in coal seams is based on our
knowledge of the total content of this gas in coal. The most important parameter determining the potential
of coal seams to accumulate methane is the sorption capacity of coal a. It is heavily influenced by the
degree of coalification of the coal substance, determined by the vitrinite reflectance R0 or the content of
volatile matter V daf. The relationship between the degree of coalification and the sorption capacity in the
area of the Upper Silesian Coal Basin (USCB) has not been thoroughly investigated, which is due to the
zonation of methane accumulation in this area and the considerable changeability of methane content in
various localities of the Basin. Understanding this relationship call for in-depth investigation, especially
since it depends on the analyzed reflectance range. The present work attempts to explain the reasons for
which the sorption capacity changes along with the degree of coalification in the area of Jastrzębie (the
Zofiówka Monocline). The relationship between parameters R0 and V daf was investigated. The authors
also analyzed changes of the maceral composition, real density and the micropore volume. Furthermore,
coalification-dependent changes in the sorption capacity of the investigated coal seams were identified.
The conducted analyses have indicated a significant role of petrographic factors in relation to the accumulation
properties of the seams located in the investigated area of USCB.