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.