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Chronostratigraphy of the Vistulian glaciation on the Kujawy Moraine Plateau (Central Poland) based on lithostratigraphic research and OSL dating

100%

Przegiętka K. R. , Chruścińska A. , Oczkowski H. L. , Molewski P.

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tom Vol. 32

69-77

EN

The subject of the investigations presented here is fixing dilemmatic character (transgressive or recessive) of the Poznań phase of the Vistulian (Weichselian) Glaciation and answering the question about the possibility of lithostratigraphic separation of this phase from the Leszno phase in the region of so called Vistula lob. Here we present the outcomes of the research project carried out on a few tills exposures, which constitute the sedimentological record of the last ice sheet advance on the Kujawy Moraine Plateau. The absolute ages of 17 samples (collected from fluvial deposits uncovered in the geological logs) have been determined by means of the OSL method applying the single aliquots regenerative (SAR) dose protocol. The OSL data are analysed with regard to supposed bleaching conditions at the moment of the last transport and deposition of the material. In conclusion, some remarks on suitability of fluvial sands for OSL dating are made. In most of the investigated sites, there appears to exist only a single till level associated with the main stage of the Vistulian Glaciation. This fact and the results of OSL dating support the hypothesis, that the Poznań phase in Kujawy Moraine Plateau is not a distinct lithostratigraphic unit, but it is a recessive phase of the last glaciation.

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Age of the Vistula River overbank deposits in Toruń

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Szmańda J. B. , Oczkowski H. L. , Przegiętka K. R.

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2004

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tom Vol. 23

35-38

EN

The paper presents luminescence dates of the overbank deposits accumulated on the Bazarowa Holm in Toruń. From these results we conclude that the flood deposits accumulation was started in this part of the Vistula river valley between 1000 and 2000 years ago. Deforestation and following increase of the floods. events intensity, which occurred in early Middle Ages, may be the possible reasons for the aggradation phase on the flood plane.

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

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Weckwerth P. , Przegiętka K. , Chruścińska A. , Woronko B. , Oczkowski H. L.

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tom Vol. 38, no. 4

397-412

EN

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 begin-ning 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 devel-oped. 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.

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Evolution of St. Laurent Mountain near Chełmno based on luminescence dating

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Chruścińska A. , Lankauf K. R. , Luc M. , Oczkowski H. L. , Przegiętka K. R. , Szmańda J. B.

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2004

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tom Vol. 23

27-34

EN

Luminescence dating was applied in the studies on the evolution of the St. Laurent Mountain in Kałdus (Lower Vistula Valley, Poland), where archaeological excavation revealed a settlement sequence. The core of the hill is constituted by eolian sands which formed the dune. Above them there is a sequence of deposits consisting of three levels of the silty sand anthropogenic deposits separated by top eolian cover and a layer of the burnt material. Three samples from the eolian base and one from the eolian cover were taken for luminescence analysis. The absolute age was established by a comparison of TL and OSL results. The basement of the St. Laurent Mountain (till and ablation sands) was created by a receding glacier during or short after the last glacial period. It suggests the age limit for the dune not older than 18,000 years. Luminescence dating indicates, that the dune formation was initiated in Pleniglacial just after deglaciation, ca. 16,500 years ago and the top eolian cover was established in Neolithic Age, between 6000 and 8000 years ago. Numerous archaeological findings from the upper part of the mountain and C-14 dates of the burnt material provided data for reconstruction of the last phase of this formation.