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

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

Geochronometria

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2011

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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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Using the TL single-aliquot regenerative-dose protocol for the verification of the chronology of the Teutonic Order Castle in Malbork

Chruścińska A., Jesionowski B., Oczkowski H. L., Przegiętka K.

Geochronometria

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2008

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Vol. 30

61-67

EN

The Teutonic Order Castle in Malbork is one of the precious medieval monuments in Europe. Because of the lack of natural rock resources in Pomerania, its walls are built almost exclusively of bricks. The huge volume and rich historical knowledge about the Malbork Castle makes it a marvellous object for TL dating. The parts of well known age can serve for the verification and improvement of dating method. Subsequently, gained in such way knowledge and experience can be applied for discovering the history of the rest of the castle. Here, the preliminary results of investigations which are still in progress, are presented for 5 brick samples. The applied TL dating procedure is described in detail. The very good accuracy of equivalent dose is achieved by the TL single-aliquot regenerative-dose protocol. The effect of wall inhomogeneity connected with the difference between the activity of the brick and mortar is discussed.

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

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

Geochronometria

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2008

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

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

Geochronometria

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2004

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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.

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Age of the Vistula River overbank deposits in Toruń

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

Geochronometria

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2004

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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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Chronology of the Vistulian (Weichselian) glacial events in the Lower Vistula region, middle-north Poland

Wysota W., Lankauf K. R., Szmańda J., Chruścińska A., Oczkowski H. L., Przegiętka K. R.

Geochronometria

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2002

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Vol. 21

137-142

EN

Stratigraphy of the Vistulian glacial events in the southern part of the Lower Vistula region in the north Poland is presented. Lithostratigraphic units and TL dating of Vistulian deposits exposing along the Vistula valley between Toruń and the Chełmno Lakeland are described in detail. The obtained results indicate that the Vistulian sequences in the Lower Vistula region were deposited during five palaeogeographical episodes. Three glacial events were distinguished: the first at the beginning of the Middle Vistulian (~65O70 ka) and two younger ones during the Late Vistulian. The Middle and Late Vistulian glacial events were separated by a long ice-free period, between 65 and 30 ka.

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The parameters of traps in K-feldspars and the TL bleaching efficiency

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

Geochronometria

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2001

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Vol. 20

15-20

EN

The fractional glow technique (FGT) applied to the investigation of optically bleached samples of K-feldspars extracted from sediments reveals the coexistence of various groups of traps which are active in the same temperature region over 300 °C. Significant differences between the trap parameters seem to explain the diversity of TL bleaching efficiency for different trap groups.

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Gamma spectrum analysis for environmental nuclides

Oczkowski H. L.

Geochronometria

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2001

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Vol. 20

39-44

EN

This paper is related to problems concerning thermoluminescence (TL) dating procedures. In our TL dating laboratory the annual dose rates are determined from the high-resolution gamma spectrometry measurements. For spectral investigations a Canberra spectrometer with the HPGe detector and Marinelli geometry (0.5 l capacity) with a shield is used. The method for spectral analysis of radioactivity is based on the Sampo90 computer program. The results of deconvolution of composite gamma-emission lines with strongly overlapping peaks are presented in detail. The typical peak table of environmental samples, which is used as a reference table in our dating procedure, is shown with the respective gamma-ray intensities. Identification procedure is discussed in the context of the natural nuclide and series activity calculation.

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Calibration standard for use in gamma spectrometry and luminescence dating

Oczkowski H. L.

Geochronometria

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2001

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Vol. 20

31-38

EN

In our TL dating laboratory the dose rates are determined from high-resolution gamma spectrometry measurements. A Canberra spectrometer with HPGe detector and Marinelli geometry (0.5 l capacity) is used. Spectral analysis is based on the Sampo90 computer program. The users have to supply the program with the detector efficiency as a function of gamma ray energy. Long-term changes in sensitivity of gamma-ray detectors lead to a drift in detector efficiency over a period of time. A uranium pitchblende source is investigated here for use in the system calibration. This calibrated source is a tempting alternative, especially for TL dating procedure, because of its long half-life and wide range of gamma-ray energies. Moreover, for a standard geometry (Marinelli) and matrix (quartz), the self-absorption and coincidence corrections for the calibrated and measured samples are comparable. The numerical deconvolution of spectral multiplets from the uranium pitchblende source with strongly overlapping peaks is verified experimentally. Several multiplets are used in the calibration procedure.

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Gamma spectrometry in thermoluminescence dating

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

Geochronometria

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2000

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Vol. 18

57-62

EN

The aim of this paper is to present in detail a method, adopted in our laboratory, for the determination of annual dose. In particular, an analysis is focused on the thermoluminescence dating of eolian sediments from Kępa Kujawska. The advantage of the presented method is that partial matrix doses for alfa, beta and gamma radiation are determined simultaneously from the high resolution gamma spectrometry measurements.

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Dating of the dune in Kępa Kujawska

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

Geochronometria

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2000

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Vol. 18

63-68

EN

A dune in Kępa Kujawska is located on the edge of the Toruń Basin. Preliminary studies on the natural thermoluminescence (TL) revealed relative chronology of the dune. The TL profile exposed three stages of the dune formation, which are correlated with three eolian members of dune deposits indicated by sedimentological investigations. The experiments on optical bleaching show that light (sunlight as well as laboratory light) only partially resets natural TL in that material. The high level of residual TL was taken into account in absolute dating of the dune. The TL ages obtained for quartz sand from the upper member are confirmed by radiocarbon dating of soil and burn horizon in proximal part of hte dune. Archaeological remains found in the dune give another evidence for truthfulness of TL dating results. The TL age of the middle member is consistent with conclusions from pollen analysis in the dune and its environments. The formation of this dune was started in the Late Glacial, probably in the Younger Dryas. In this period eolian deposition was stimulated by variable climate conditions. The upper member of the dune is connected with Neolithic and Iron Cultures when anthropogenic activity initiated eolian processes again. During the Atlantic and the Subatlantic periods the dune was rebuilt.

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Beta source calibration for thermoluminescence dating

Oczkowski H. L., Przegiętka K. R.

Geochronometria

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2000

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Vol. 18

53-56

EN

The results of calibration of the dose rate from the beta source, incorporated in the RISO TL/OSL SYSTEM TL-DA-12, are presented. The quartz grains, separated from sediments by a typical procedure applied for thermoluminescence (TL) dating were used as a dosymetric material. The stability of thermoluminescence sensitivity of the material was achieved by the sequence of irradiating and the subsequent annealing of the grains. The calibrated 60Co and 137Cs sources were applied for irradiation with reference gamma doses. The calibration performed in January 1998 confirms the result obtained in 1996 with respect to the decay of activity of the beta source in the meantime.