Geographia Polonica (1988) vol. 55

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Levels in subglacial channels and their significance in determining the channel origin and evolution

Niewiarowski Władysław

Geographia Polonica (1988) vol. 55, pp. 113-128

Abstract

The present author points out that only in some large subglacial channels of the Dobrzyń Lakeland there are glacial till horizons indicative of ice-sheet participation in their formation. In subglacial channels cut out subglacially by glacial water, which prevail in the study area, the horizons are likely to occur as fluvioglacial erosional levels. There are fluvioglacial accumulative horizons along subglacial channels where outwash water flowed away, independently of their origin, while kame terraces occur in some of large channels filled up with dead ice. There exist lake terraces in subglacial channels in which there were or still are lakes, whereas fluvial terraces are present in considerably transformed channels. Analysis of these levels reveals the origin of channels and allows establishment of channel evolution stages during the Lateglacial and Holocene.

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Niewiarowski Władysław, Institute of Geography, Nicholaus Copernicus University, Fredry 8. 87-100 Toruń, Poland