6914375141

STEFAN JEWTUCHOW1CZ

ORIGIN OF THE WARSAW—BERLIN PRADOLINA BETWEEN THE

RIVERS NER AND MOSZCZENICA

Summary

The eastern part of the Warsaw—Berlin pradolina lies in central Poland. The author has studied only the section between the rivers Ner and Moszczenica (Fig. 1). Because the origin and the development of this form were linked to the origin and the development of neigh-bouring area, the so called Kutno end-moraine ridge, with is adjacent to the pradolina on the north, was also included in the study.

The investigations included the surface of the Ouaternary bedrock, the stratigraphie of Ouaternary formations, the morphology of the pradolina and the Kutno end-moraine ridges.

Deep borings were madę to investigate the Ouaternary bedrock, the structure of which is shown on two parallel sections running from south-east to north-west (Figs. 3, 4).

Sections showing the naturę of the bedrock are supplemented by a map of the sub-Quaternary surface (Fig. 5). The surface is dissected by valleys and elevations rising to 115 m. above sea level. Because of the dominant inclination of the sub-Quaternary surface, the principal depression in that pattern is formed by the pradolina channel, to which the other valleys lead from north and south.

The Pleistocene deposits of the investigated areas consist largely of boulder-clay, ranging from 0.5 to 90 m. in thickness. The outstanding characteristic of the boulder-clay is their lack of uniformity. Boulder--clay of the same horizon differ in grain-size, the morphology of grains and the content of feldspar. This differentation is due to ice-sheet erosion.

Boulder-clays are interbedded by sand, gravel and silt. These deposits average 15—20 m. in thickness, though occasionally reach 75 m.