Uwagi na temat rozwoju i stratygrafii piaskowca pstrego w Polsce północno-wschodniej

Abstract

NOTES ON DEVELOPMENT AND STRATIGRAPHY OF BUNTER SANDSTONE IN NORTHEASTERN POLANDIn the territory of Northeastern Poland, sediments of the Bunter Sandstone appear underneath an overburden of younger sediments of several hundred meters thickness, and are known here solely from deep bore-holes (Fig. 1).In their majority, these series are very much reduced and devoid of fauna; their division into a lower and a higher series was made chiefly on the basis of lithoIogical analogies and sedimentological premises.The development of the Bunter Sandstone in this area differs markedly from the structure of the Bunter Sandstone in the central part of the Lower Triassic basin, and illustrates to a high degree the differentiation in geomorphological structure of the Subtriasic substratum.The maximum thickness of the Bunter Sandstone in this area has been observed in bore-hole Pasłęk where it exceeds 500 m. On the remaining area, this thickness gradually changes towards north, northeast and southeast (Fag. 2).On the basis of more recent investigations and with due consideration of data from the adjoining Soviet regions it seems necessary to shift the boundary of occurrence of the Bunter Satndstone far eastwards, embracing almost the entire area of Northeastern Poland.Sediments of the lower Bunter Sandstone cover nearly all of this area, with the exception of some eastern most sections situated on its eastern boundary. The eastern boundary of their actual occurrence has been illustrated in Fig. 3.The boundary of the present-day range of the upper part of the Bunter Sandstone shifts somewhat further east than does the range of the lower part (Fig. 4).Northwards, sediments of the Bunter Sandstone reach far beyond the territory of Poland, their range comprising the entire Lithuanian depression (Fig. 2).