Liptinite as an indicator of environmental changes during formation of coal seam No. 207 (Upper Silesia, Poland)

Abstract

The coal seam No. 207 was a subject of palynological and petrographic studies. According to the results of the vitrinite random reflectance measurements supplemented by moisture and calorific value determinations, the rank of this coal is matching the boundary between sub-bituminous and bituminous coals. The aim was to reconstruct the environmental conditions during the biochemical stage of seam formation, as well as the facies development throughout the seam profile. The maceral (incident and fluorescence mode) and microlithotype compositions (incident light) supplemented by palynological analyses, show that there were two main facies developments. In the authors opinion, they correspond with a phase of ombrogenous, raised bog marked by the presence of crassidurite with Densosporites variabilis and a wet-forest swamp phase represented by vitrite and clarite with more diverse spore assemblage including densospores. Other minor but distinctive sediments, a cannel layer and a reeds facies, both occurring in the lower part of the seam. Above the tonstein horizon, a dry forest type of sedimentation is recognized.