<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><p>The deposits of the Toruń Basin are dominated by a few-metre thick sand series which fill up buried valley-like depressions. In many cases they underlie the Weichselian till which builds up the ice marginal streamway (pradolina) terraces or they are exposed at the basin slopes. As the results of the geological and sedimentological studies, as well as of the dating of the deposits at the sites in the Toruń Basin indicate, the deposits include two fluvial series accumulated before the advancement of the Leszno Phase ice sheet, i.e. in Middle Weichselian and at the beginning of Late Weichselian. The oldest fluvial series connected with the Saalian Glaciation was found at the mouth section of the Drwęca Valley. The fluvial system of the Toruń Basin during Middle Weichselian and at the beginning of Late Weichselian developed in two phases of the sand-bed braided river. During the first one the river channel were dominated by large mid-riverbed sandbars, while during the second phase the water flow was smaller and, as a result, low transverse sandbars and two-dimensional dunes developed. Other active river channel also showed low-energy flows, more intensive meandering than in the case of the braided rivers, as well as sandy side-bars. Analysis of the rounding and frosting of the quartz grains indicate that the studied series of the Weichselian sandy deposits represent alluvia of a river which were fed from two diverse sources. The first one might have represented the alluvia of a warm river which transformed its load, while the other one might have mainly carried the underlying Quaternary deposits.</p></abstract>

The deposits of the Toruń Basin are dominated by a few-metre thick sand series which fill up buried valley-like depressions. In many cases they underlie the Weichselian till which builds up the ice marginal streamway (pradolina) terraces or they are exposed at the basin slopes. As the results of the geological and sedimentological studies, as well as of the dating of the deposits at the sites in the Toruń Basin indicate, the deposits include two fluvial series accumulated before the advancement of the Leszno Phase ice sheet, i.e. in Middle Weichselian and at the beginning of Late Weichselian. The oldest fluvial series connected with the Saalian Glaciation was found at the mouth section of the Drwęca Valley. The fluvial system of the Toruń Basin during Middle Weichselian and at the beginning of Late Weichselian developed in two phases of the sand-bed braided river. During the first one the river channel were dominated by large mid-riverbed sandbars, while during the second phase the water flow was smaller and, as a result, low transverse sandbars and two-dimensional dunes developed. Other active river channel also showed low-energy flows, more intensive meandering than in the case of the braided rivers, as well as sandy side-bars. Analysis of the rounding and frosting of the quartz grains indicate that the studied series of the Weichselian sandy deposits represent alluvia of a river which were fed from two diverse sources. The first one might have represented the alluvia of a warm river which transformed its load, while the other one might have mainly carried the underlying Quaternary deposits.

Age and sedimentological features of fluvial series in the Toruń Basin and the Drwęca Valley (Poland)

Institute of Geography, Nicolaus Copernicus University, Gagarina 9, 87-100, Toruń, Poland

Institute of Physics, Nicolaus Copernicus University, Grudziądzka 5/7, 87-100, Toruń, Poland

Faculty of Geography and Regional Studies, University of Warsaw, Krakowskie Przedmieście 30, 00-927, Warszawa, Poland

Geochronometria

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The deposits of the Toruń Basin are dominated by a few-metre thick sand series which fill up buried valley-like depressions. In many cases they underlie the...

Age and sedimentological features of fluvial series in the Toruń Basin and the Drwęca Valley (Poland)

Published Online: Sep 22, 2011

Page range: 397 - 412

DOI: https://doi.org/10.2478/s13386-011-0038-1

Keywords
Weichselian Glaciations, sand-bed braided river, sinuous channel, Toruń Basin, OSL dating, frosting and rounding analysis of quartz grains

© 2011 Silesian University of Technology, Gliwice, Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Age and sedimentological features of fluvial series in the Toruń Basin and the Drwęca Valley (Poland)

Published Online: Sep 22, 2011

Page range: 397 - 412

DOI: https://doi.org/10.2478/s13386-011-0038-1

KeywordsWeichselian Glaciations, sand-bed braided river, sinuous channel, Toruń Basin, OSL dating, frosting and rounding analysis of quartz grains

© 2011 Silesian University of Technology, Gliwice, Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
Weichselian Glaciations, sand-bed braided river, sinuous channel, Toruń Basin, OSL dating, frosting and rounding analysis of quartz grains