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This paper presents the first attempt to reconstruct the facies development of the entire Carboniferous coal deposit with an area of 38.50 km2, in the western part of the Upper Silesian Coal Basin based on microscopic microlithotype analysis. For this purpose, eight coal seams in the Knurów deposit were sampled. Samples were taken from all stratigraphic series of exploited seams and exploratory boreholes. This paper reconstructs the transition of environments between eight coal seams extracted in the active Knurów coking coal mine in the Upper Silesian Coal Basin, using microlithotype analysis of the whole seam basis on the fifty coal samples. Facies diagrams proposed in the literature by other researchers were used to reconstruct the depositional environments. The dominant microlithotypes in the coking coal of the Knurów deposit are vitrite (in the range from 19.96 vol% for coal seam No. 504 to 42.96 vol% for coal seam No. 355) and duroclarite (in the range from 20,57 vol% for coal seam No. 410 to 33,65 vol% for coal seam No. 405/1). The distribution of the samples indicates two dominant peat-forming environments. These are telmatic reed moor rich in duroclarite and telmatic forest moor rich in vitrite. This indicates a transitional environment between forest swamp and herbaceous swamp. Thus, the deposit evolved from the paralic to limnic facies. The formation of the river delta caused the progradation of terrestrial environments into the sea and the formation of extensive mires fed mainly by groundwater connected to the river system. Over time, the deposit changed from a reed facies to a forest facies. Periodically, the mires were flooded with waters formed in the proximal lacustrine delta by rising water levels or delta subsidence. The remnants of this phenomenon are interbeds in coal seams resembling macroscopic sapropelic coal rich in the clay matters and gelinite. These are layers containing vitrite in the range of 52.99–59.06 vol% and mineral matter in the amount of 19.76–34.59 vol%. The evolution of the basin proceeded from the paralic to limnic stage. The main factor determining the evolution of the mire was the existing river system with periodically variable activity and intensity. • The microlithotypes analysis interprets the dominant character of the mire. • The evolution of the deposit proceeded from the paralic to the limnic conditions. • The dominant microlithotypes are vitrite and duroclarite. • The vitrinite content increased from Namurian to Westphalian. • The telmatic reed moore and telematic forest moore facies are dominant. [ABSTRACT FROM AUTHOR]

This paper presents the first attempt to develop the facies model of the entire coal deposit belonging to the Carboniferous productive sequence located in the western part of the Upper Silesian Coal Basin. To achieve this objective, six seams from the Knurów deposit were examined. The deposit belongs to the largest producer of coking coal in Europe, which is Jastrzębska Spółka Węglowa SA (Polish state-run coking coal producer). The maceral composition, vitrinite reflectance, ash yield content, moisture content, gross calorific value, and volatile matter yield were determined. Coals from the Knurów deposit are classified as ortho-bituminous and meta-bituminous coals. Their average degree of coalification, determined by vitrinite reflectance, is R O = 0.79% to R O = 1.09%. Petrographic indices and the analysis of facies diagrams were used to develop the facies model. It was shown that the facies development and sedimentological evolution of the Knurów deposit were determined by the river system extended to the upper delta plain. In accordance with the stratigraphic succession, the oldest deposits are dominated by the reed facies (mainly Calamites) growing in oxbow lakes and dry streambeds. With the passage of time, the importance of the river system for the development of the paleo-environment decreased. Transitional bogs with mixed plant communities were formed. This started the conversion of wetlands into areas occupied by wet forest. At the end of the sedimentation of the documented coal seams in the Knurów deposit, lowland bogs (fens), which were subject to frequent fires, dominated the landscape. Based on a detailed maceral analysis and facies diagram analysis, a strong correlation between fault occurrence and coal facies developed under paleo-river influence was displayed. The aim of the study is to show environmental changes during deposit formation in the context of geological exploration. • Petrographic analysis was used to study the Knurów deposit. • Environmental changes were reproduced using petrographic indicators. • The Knurów deposit changed from paralic to limno-telmatic conditions. • The deposit was changing from herbaceous swamp to wet forest and fen. • The deposit developed in the upper delta plain and piedmont plain. [ABSTRACT FROM AUTHOR]

Abstract: Laboratory tests were carried out on coal samples taken from mine openings of selected coal mines in the Upper Silesian Coal Basin. The analyses involved maceral composition (vitrinite, inertinite and liptinite group) and vitrinite reflectance on the one hand, and reservoir parameters (coal permeability and effective porosity) on the other. The results are compared. Samples with high values of coal permeability are characterized by vitrinite contents of ca 60%, and samples with the lowest permeability by vitrinite contents of 40%. The vitrinite-rich bright coals are brittle and prone to crushing caused by tectonic pressures. Moreover, coal permeability is more strongly anisotropic in the bright coals of the Cracow Sandstone and the Mudstone Series than in the dull coals of the Upper Silesian Sandstone Series. In bright coals, permeability is much along the direction parallel to vitrain layers. Good reservoir parameters such as permeability and effective porosity are crucial for fluid flow through the coal seams and, thus, successful coalbed methane exploitation. In the Upper Silesian Coal Basin, Cracow Sandstone- and Mudstone Series with vitrinite-rich coals should be a good target, though serious geological problems must first be overcome. [Copyright &y& Elsevier]