Litostratygrafia pstrego piaskowca w Polsce i projekt jej usystematyzowania

Abstract

 Przedstawiono stan litostratygrafii pstrego piaskowca w Polsce. Omówiono używane obecnie podziały litostratygraficzne oraz ich korelacje. Zaproponowano, w wyniku dyskusji między specjalistami, sposób uproszczenia i ujednolicenia istniejących podziałów, który stanowić będzie punkt wyjścia dla dalszych prac nad systematyzowaniem i formalnym wprowadzeniem podziałów. LITHOSTRATIGRAPHY OF THE BUNDSANDSTEIN OF POLAND AND PROJECT OF ITS SYSTEMATIZATION Organic remains are exceptionally scarce in Bundsandstein rocks and their occurrence is limited to some complexes separated by paleontologically barren in the section. That is why the lithostratigraphic subdivision is still the basic for these rocks. Several stratigraphic schemes, often markedly differing from one another, were hitherto proposed for rocks of that age from various parts of the country. The resolution and publication of “The Polish guide to stratigraphic classification, terminology and nomenclature” (S. Alexandrowicz et al., 1975) stimulated the attempt to order the stratigraphic schemes and to make them as uniform as possible.The analysis of the hitherto proposed subdivisions (Tables 1–7), carried out with reference to the knowledge of paleogeographic-lithofacies development of the Bundsandstein, showed that the unification is possible on the limited scale only. In Poland, it appears necessary to differentiate four regions (I–IV see Fig. 1), differing in the course of sedimentation of the Bundsandstein and requiring the use of different stratigraphic subdivisions. This may be explained by the effects of crossing of influence; of a number of alimentary areas, the intensity of supply of clastic material from which was varying in time, as well as a marked paleotectonic variability of sedimentary area in Poland.The subdivisions may be uniformized for each of the above regions. By agreements made among specialists working in these regions, there were elaborated projects of subdivisions of the Bundsandstein for each of them (see the last columns in Tables 1, 2, 3, 5, 6, 7 and Table 8). Some major elements, usable in correlations, are emphasized in the subdivisions. The elements include: 1 –sedimentary-erosional discontinuity surfaces, 2 – surface; separating complexes differentiated with reference to criteria implicating their isochronity over vast areas, 3 – sulfate and sulfate-chlorine rock complexes, 4 – complexes bearing organic remains indicative of marine sedimentary environment.At least one of formations differentiated for any of the above regions is also known from the neighbouring one, which facilitates both the correlation of subdivisions and the analysis of contacts between the remaining formations of the subdivisions. The relations between the proposed subdivisions are shown at the background of sketch lithofacies sections (Figs. 1–2) and in Table 8.The proposition presented here is the starting point for further works on ordering of lithostratigraphy of the Bundsandstein. The works should end with elaboration and formal introduction of lithostratigraphic subdivisions for these strata.