Problemy stratygrafii silezu w Dolnośląskim Zagłębiu Węglowym

Abstract

STRATIGRAPHICAL PROBLEMS OF THE SILESIAN IN THE LOWER SILESIAN COAL BASINSummaryThe Lower Silesian Coal Basin is situated in the north-eastern part of the Bohemian massif, within a vast synclinorial form, known as the Intra-Sudetic basin (Fig. 1). Here are found Silesian deposits laid down after the main phases of tectonic deformations of the Variscan orogeny. They are developed in a continental facies. The article presents the results of studies on the stratigraphy and on the continuity of the stratigraphical profile recently discussed very intensely.The profile is restricted at the bottom by the Visean deposits, with marine fauna, which pass upwards into the continental deposits of the Wałbrzych Beds, the age of which is thought to be, according to microfloristic and marcrofloristic  examinations - Lower Namurian A. Higher up, there are found at places the Upper Namurian A deposits (at Pniaki) and the Lower Namurian B deposits (Beds from Przedwojów), evidenced palynologically. The Lower Namurian deposits are overlain with the conglomerates of the Biały Kamień Beds (Namurian B-C, evidenced palynologically and by macroflora remains).The Biały Kamień Beds are separated from the underlying deposits by a disconformity. At the top they pass into the Zacler Beds. The Biały Kamień Beds and the Zacer Beds (considered as a whole) rest nonconformably on the differentiated older basement. Deposite the suggestions of some authors no evidences appear to prove the continuity of the stratigraphical prolfile from the Lower Namurian to the Welstphalian. Both the gaps and their location ensue from the comparison of the profiles (Fig. 2) and from the comparison with the Upper Silesian Coal Basin recording to the biorstratigraphical dating – Table 1.There are distinguished the Lower and the Upper Zacer Beds. The age of the Lower Zacer Beds has been determined (on macroflora) as the Westphalian A and the Lower Westphalian B, that of the Upper Zacler Beds – as the Upper Westphalian B, C and D (on macroflora). Within the Upper Zacer Beds the Beds from Glinik are distinguished as a lithofacial equivalent rather than a stratigraphic horizon.The uppermost member of the Silesian is probably represented by the carse-clastic deposits of the Berds from Ludwikowice and Unisław, though their position has not been biostratigraphically documented. These are overlain with the Anthracosia beds in which beside the microflora assemblage, characterized by some transition features from Stephanian to Autunian, are found also, representatives of Callipteris conferta B r o n g n.