CHARAKTERYSTYKA WĘGLA BRUNATNEGO Z MIOCENU NIŻU POLSKIEGO NA PODSTAWIE WYBRANYCH PROFILI

Abstract

LIGNITE OF THE POLISH LOWLANDS MIOCENE: CHARACTERISTICS ON A BASE OF SELECTED PROFILESAbstract. Some selected profiles of three Neogene lignite seams outcropped within opencast mines in the Polish Lowlands and satellite basins have been examined for comparison of macro- and microfacies and geochemical features. The investigations included: sedimenological research, paleobotanical investigation (particularly palynological analysis), lithological and petrographic study of lignite and geochemical examinations of coal have been made there. Some facies related to recent lacustrine/paludal sedimentary subenvironments, qualified at first by hydrological conditions and corresponding with floristic habitats have been established. The most complete inventory of sedimentary subenvironments has been defined within the 2nd lignite seam in the Zittau Basin. The sedimentary subenvironment succession and related floral communities is generally conformable with a natural plant succesion of a lake overgrowth. However, it was frequently interrupted after groundwater level changes: uplifting in the result of autochtonic mechanism (compaction of underlying sediments, most substantial in the case peat to lignite) and allochtonic one (tectonic subsidence). Also sedimentary factors, like progradation of clastic lithosomes and elevation of erosional base after eustatic movements could take part in the disruptions. The examination show that only integrated macro- and microfacial analysis makes it possible to present a reliable reconstrustion of the coal-forming sedimentary environment. The reconstruction of the succession of plant communities and conclusions on hydrological/ hydrogeological conditions are the most substantial results of the work.