Korelacja profilów dolnego i środkowego pstrego piaskowca w zachodniej Polsce

Abstract

CORRELATION OF THE LOWER AND MIDDLE BUNTSANDSTEIN SECTIONS IN WEST POLANDSummaryThe deposits of the Lower and Middle Buntsandstein in West Poland are comprised by two stratigraphical schemes, different as concerns the northern and the southern parts of this area. Despite same differences observed in the development of lithofacies the sections of the Lower and the Middle Buntsandstein of the whole area of West Poland can be correlated. As the main correlation plane can serve the bottom planes of the individual sandstone complexes of the Middle Buntsandstein, and the bottom plane of the lowermost horizon of the anhydrite Roethian. As a result of the correlation, boundary has been defined between the Lower and Middle Buntsandstein within the western areas of Poland, by displacing it in the Pomeranian area to the bottom of a member so far determined (A. Szyperko-Śliwczyńska, 1965) as an upper series of the Lower Buntsandstein (Fig. 1). The deposits resting above this boundary are called now the "Pomerania series" (= the upper series of the Lower Buntsandstein as called previously) and the ''Połczyn series" (= Middle Buntsandstein according to the previous terminology). Within the Sudetic area, the bottom boundary of the Roethian is placed somewhat higher than in the remaining areas (J. Sokołowski, 1967). Its unification can be made by displacing it to the bottom of the "series 12" of the Middle Buntsandstein. Within the area of West Poland the Lower Buntsandstein is very uniform, as concerns its lithology and thickness. From the very beginning of the Middle Buntsandstein time this area had been differentiated into the areas characterized by either increased or decreased subsidence. In the central part of the area there is visible a zone of a NW-SE direction (Myślibórz-Międzychód-Gostyń), which, at the end of the Middle Buntsandstein, changed into an elevated horst-like structural element. Its central portions lack deposits of the uppermost part of the Middle Buntsandstein. The lowermost Roethian deposits rest here discordantly on the partly denuded formations of the lower members of the Middle Buntsandstein.