| Summary: | GLACIAL FLOES (BEDROCK MASSES) SQUEEZED BY ICE-SHEETS IN MID-EASTERN POLAND (PRELIMINARY REPORT)SummaryThe area in question is situated SE of Warsaw, stretching to the east as far as Łosice and Radzyń Podlaski. The author examined the stratigraphy of Quaternary deposits on this territory, and has stated here five main horizons of glacial accumulation. The oldest one corresponds to the Podlasian (Günz) Glaciation, which has reached only the northern part of territory. The two successive horizons are connected with the Cracovian (Mindel) Glaciation, and the two youngest ones with the Middle Polish (Riss) Glaciation. Quite numerous glacial floes (in American literature called often "bedrock masses") have been stated within the quoted glacial series. The floes drew attention of the author and became main object of her investigations. She laid stress on the examining such features, which might explain the process of formation of the floes. Same questions concerning this process may already be answered in this preliminary report. The glacial floes have been hitherto investigated within two series of glacial accumulation corresponding to the Cracovian Glaciation. Some of the floes reveal to have been originated from squeezing process caused by the pressure of advancing ice sheet, and these ones, called by the author the squeezed floes, are the chief subject of this report. They are discussed on the basis of boring material from Łuków (the famous Jurassic floe from Łuków is involved within the younger deposits, and it not discussed here) and Mińsk Mazowiecki east of Warsaw, and of exposure from Wyszogród on the Vistula. In Ł u k ó w the bedrock of the Quternary deposits consists of sandy and silty "Preglacial" series underlaid by thin Pliocene clays and lower down by sandy-clayey Miocene series and by Oligocene sands (Fig. 1). In the northern part of the town a depression about 20 m deep is clearly marked (Fig. 2). Its bottom reaches the Oligocene sands, and it is filled with glacial deposits. The geological section ...
|
|---|