Changes of coal rank and petrographic composition of coals from the drillhole BD 57 deposit of "Bzie-Dębina" in the Jastrzębie area (SW part of the Upper Silesian Coal Basin)

The aim of the work was to characterize in coalification parameters (moisture content Wa, volatile matter Vdaf and random reflectance of vitrinite R) and changes in petrographical composition of coal from the Bzie Dębina drillhole (BD 57). The object of examination were representative coal seams from the BD 57 drillhole. It was found increase of coal rank is expressed by a reduction of moisture content and volatile matter and the increase reflectance with depth. In petrographic composition vitrinite group macerals (Vtmmf= 65.8-91.0%) dominate over the inertinite group (Immf = 6.2-28.4). Participatiof liptinite maceral group is low (Lmmf = 1.9-5.8%). Inertinite macerals group participation does not increase with coal rank, unlike in the Zofiówka monocline.