Andrzej Bluszcz

Extraction and AMS radiocarbon dating of pollen from Lake Baikal sediments

This work focuses on the preparation and dating of sporomorph (pollen and spores) concentrates of high purity. Three sediment cores recovered from Lake Baikal within the EU-Project CONTINENT were subjected to palynological analyses and accelerator mass spectrometry (AMS) radiocarbon dating. Laboratory processing of concentrates was aimed at the removal of non-sporomorph organic matter by means of chemical treatment, micro-sieving, and heavy liquid separation. The obtained concentrates were checked under the microscope and sample purity was estimated on the basis of particle counts. The results of AMS (super 14) C dating show differences in the sedimentation rate among 3 sites of Lake Baikal.

Application of α and γ Spectrometry in the 210Pb Method to Model Sedimentation in Artificial Retention Reservoir

Application of α and γ Spectrometry in the 210Pb Method to Model Sedimentation in Artificial Retention Reservoir The paper describes the application of the 210Pb method for creating a comprehensive model of sedimentation in the retention reservoir Kozłowa Góra during the 60 years of its use. The model takes into account the temporal and spatial change in the sedimentation conditions. Because of the specific conditions of the young artificial lake, the techniques available to date are not sufficient and it was necessary to modify the 210Pb method. The paper describes such modification of the method and its application to dating the sediments in the reservoir. For a young lake it is impossible to estimate the activity of authigenic 210Pb with the application of alpha spectrometry because even the oldest sediments contain allochthonous 210Pb. The determination of the activity of authigenic 210Pb in the sediments of the studied reservoir was possible only thank to gamma spectrometry. The gamma ray spectrometry consists of measurements of gamma photons emitted by 210Pb, 214Pb and 214Bi isotopes. Analysis of the 210Pb gamma spectrum line yields information about total activity of 210Pb, while the assessed activity of 214Pb and 214Bi equals to the activity of authigenic 210Pb.

Luminescence dating of the Morasko (Poland), Kaali, Ilumetsa and Tsoorikmäe (Estonia) meteorite craters

Luminescence Dating of the Morasko (Poland), Kaali, Ilumetsa and Tsõõrikmäe (Estonia) Meteorite Craters The TL dating of sinter crust of Morasko meteorites proves that the extraterrestrial matter fell about 5000 yr BP. Similar data were obtained for the Kaali impact. The OSL analyses show incomplete bleaching of old rock material especially in the Estonian craters. Almost all data obtained for the immediate impact area indicate ages younger than the Quaternary morphogenesis. The method used seems promising for determining the age of impacts and the origin of small depressions of unknown genesis.

Influence of the Parameters of Models used to Calculate Soil Erosion Based on 137Cs Tracer

Influence of the Parameters of Models used to Calculate Soil Erosion Based on 137Cs Tracer Soil erosion is a serious problem especially on arable land in the loess areas of southern Poland. Reliable data of soil erosion are important to propose a proper method of soil conservation. Measurements of 137Cs inventory allow obtaining both long-term mean value of soil erosion and spatial pattern of soil erosion. To obtain quantitative results of soil erosion from 137Cs measurements one of the mathematical models must be used. Currently, there are many such models in circulation and the results of calculations of soil erosion depend not only on the particular model but also on values assumed for parameters of this model. This paper describes some problems related to calculating soil erosion and deposition based on 137Cs data, namely, the influence of additional parameters on calculated soil erosion is considered. In particular, we have considered the influence of values assumed for plough depth, γ factor, particle size correction factor, soil density and the contribution of the post-Chernobyl deposition to the total caesium deposition on the calculated soil erosion values. The calculations of soil erosion have been done for four, most commonly used models, using real caesium inventory data collected by the authors. The influence of errors of model parameters on the results of soil erosion rate estimates is about 1%, or less for 1% relative error in the parameter.

Determination of the initial 137Cs fallout on the areas contaminated by Chernobyl fallout

Determination of the Initial 137Cs Fallout on the Areas Contaminated by Chernobyl Fallout The fallout radioisotope 137Cs is widely used to study rates and patterns of soil redistribution. This method requires the knowledge about the initial fallout of cesium in the study area. This paper describes the method of establishing the initial fallout of cesium for a study area which is contaminated by Chernobyl fallout. The study was carried out on the loess area near the Ujazd village (South-West Poland). The 137Cs activities for reference soil cores varied from 4.41(24) kBq/m2 to 5.97(26) kBq/m2. The average value of the reference inventory of 137Cs for the study area is 5.23(15) kBq/m2. The calculated contribution of the Chernobyl 137Cs fallout in the total cesium is equal 69%. Moreover the annual values of the 137Cs fallout based on the precipitation data were calculated and presented. This study provides the method of calculating the 137Cs fallout connected with the nuclear weapon testing based on the precipitation data. Moreover, this study also indicated that the spatial variability on the highly contaminated by Chernobyl cesium study area is small (RSD about 10%) and thus it is possible to use the cesium method to study soil redistribution.

Dosimetric properties of natural quartz grains extracted from fired materials

Abstract The paper describes an examination of the dosimetric properties of natural quartz grains extracted from ancient fired materials. Eleven samples of different origin were tested for their TL and GLSL (green light stimulated luminescence) sensitivities within the mGy dose range. Very promising results were obtained showing the possibility of measuring the doses of around 10 mGy with 1% precision using GLSL or TL and using the single aliqout technique for natural quartz as a dosimeter. The lowest detectable dose was estimated to be lower than 500 μGy. The results obtained indicate that natural quartz grains from selected materials could be used for the dosimetry of environmental gamma radiation for the purposes of paleodosimetric dating methods as well as for accident dosimetry.

Strategies for flexibility in luminescence dating: procedure-oriented measurement and hardware modularity

In the past decade, as problems in luminescence dating have been encountered and addressed, the once simple and standard methods for measurement have been replaced with a myriad of variations, often ad hoc. As a consequence, it has become more difficult and time consuming to program the data taking, and to manage the resulting data. As methods change, new instrumentation often must be integrated into the measurement systems, usually with difficulty. We have implemented a number of approaches for improving this situation such as devising a simple but versatile scripting language for data acquisition, a means of handling arbitrary data formats, and a new modular architecture for luminescence instrumentation. The Daybreak 2AP/1 TL/OSL reader is described as an example using this architecture. We will also suggest a number of avenues that will lead to further improvements in data handling, archiving, and inter-laboratory data transfer.

OSL chronostratigraphy for loess deposits from Tyszowce – Poland

Abstract The presented work concerns a loess profile located in Tyszowce, in the eastern part of Poland on the Volyn Upland, close to the Ukrainian border. The investigated loess formation is well preserved and is characterised by clear stratigraphic units providing an opportunity to refine the loess chronostratigraphy in Poland. In the paper, we present luminescence ages of loess from the last glacial cycle in SE Poland (up to about 100 ka) together with seven radiocarbon ages. Twenty-one samples were collected and dated using infrared (post-IR IRSL) and blue light stimulated luminescence dating. Two fractions were used, namely polymineral fine grains (4–11 μm) and medium sized quartz grains (45–63 μm). The obtained luminescence ages show very good agreement of both methods in relation to loess deposits, however for the fossil soil units the post-IR IRSL method yields older ages. Radiocarbon dates also confirm luminescence chronostratigraphy for younger units. Moreover, the luminescence results are supported by detailed analyses of grain size distribution, carbonate content and magnetic susceptibility variations allowing to create a comprehensive picture of chronological evolution of this site.

COMBINED IRSL/OSL DATING ON FINE GRAINS FROM LAKE BAIKAL SEDIMENTS

Combined IRSL/OSL Dating on Fine Grains from Lake Baikal Sediments In this work we present luminescence dating results obtained for samples taken from a gravity core of sediments of the Lake Baikal. The initial attempts to date coarse quartz grains failed because such grains were very sparse and dim. Fine grain quartz was also relatively dim and only IRSL signal from fine grain polymineral fraction was sufficient to obtain absorbed dose estimates. We made the measurements on 6-12 μm fraction extracted by differential precipitation in a water column. Samples were collected from the sediment depth range between 80-750 cm which, basing on paleomagnetic data, were expected to cover the period up to ca. 150 ka. The equivalent absorbed doses measured by means of OSL grow with depth down to 350 cm where they reach about 100-120 Gy and then apparently saturate. For the depth range 80-350 cm IRSL ages also grow almost linearly from 11 to 50 ka. Calibrated radiocarbon ages obtained for micro samples of pollen from the same site yielded an average sedimentation rate of 6.86±0.21 cm/ka for the period between 15-1 ka BP. This is in good agreement with the sedimentation rate deduced from IRSL dating (6.15±0.55).

Simultaneous OSL and TL dating of sediments

Abstract This paper presents examples of application of simultaneous OSL and TL dating to samples from two different sedimentary environments that usually give rise to a number of interpretation problems. The presented method provides means of quantifying the effectiveness of bleaching of grains during depositional processes and consequently enables deducing conditions and duration of weathering and transport processes.