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Lithological indicators of loess sedimentation of SW Poland

Krawczyk M., Ryzner K., Skurzyński J., Jary Z.

Contemporary Trends in Geoscience

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2017

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Vol. 6, iss. 2

94--111

EN

High-resolution grain-size investigations were carried out in two SW Polish loess sections: Biały Kościół (Niemcza-Strzelin Hills) and Zaprężyn (Trzebnica Hills). Each sequence was sampled by using the same methodology and samples were taken at 5 centimeters intervals. The particle size distribution was obtained with a Mastersizer 2000 laser, used for diffraction methods. From the obtained results the basic parameters and grain size indicators were calculated: Mz, Grain Size Index ratio, U-ratio and the percentage content of clay (< 4μm) and sand (> 63 μm). Both loess- soil sequences are composed of interfluve and slope loess facies and consist of five litho-pedostratigraphic units developed during the Late Pleistocene and Holocene: two loess units L1LL1, L1LL2 and three polygenetic fossil soils sets S0, S1 and L1SS1. The distance between these two profiles is about 60 km. Zaprężyn, as a section located more to the north, has almost no lower younger loess and higher level of weathering which could be related to proximity of this site to the Ice Sheet margin. The climate here was more extreme and harsh. What is more,the difference in development of soil L1SS1 can be observed: while in Biały Kościół pedogenesis process was slower and less disturbed than in Zaprężyn. The upper part of L1SS1 in Biały Kościół was deformed by gelifluction, frost heave and other periglacial processes. Mz indicator by the grain-size distribution in these sediments reflects subtle variations in the climatic system. Moreover, in Zaprężyn the content of sand fraction is higher than in Biały Kościół what can be the evidence of short episodes of strong winds during cold period of sedimentation. The aim of this paper is to compare two loess profiles by their stratigraphical and lithological similarities which are result of climate conditions and features of surrounding environment.

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Geochemical properties of the Late Pleistocene loess-soil sequence in Dankowice (Niemcza-Strzelin Hills)

Raczyk J., Jary Z., Korabiewski B.

Landform Analysis

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2015

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Vol. 29

49--61

EN

Loess-soil sequences provide one of the most continuous and detailed records of the climate changes on land areas in the Quaternary. The Late Pleistocene loess section in Dankowice (Niemcza-Strzelin Hills) is one of the best recognized in SW Poland. For the investigation of the chemical composition of loess-soil sequence in Dankowice, 31 loess samples were tested. Ten main oxides were determined (SiO2, Al2O3, Fe2O3, MnO, MgO, CaO, Na2O, K2O, TiO2 and P2O5) using certified reference materials to obtain good credibility of the analysis. The chemical composition of loess from Dankowice is similar to the results presented in the world loess literature. The characteristic feature is extremely high concentration of the silica. The chemical composition of loess in Dankowice is differentiated within the vertical sequence and confirm previous division of litho-pedostratigraphic units. Therefore, the chemostratigraphic method can be successfully used as a one of lithostratigraphic methods. Decreasing values of the chemical weathering indices to the top of the section may indicate that the source areas of loess silt have provided material over time, less and less transformed by prolonged and intense chemical weathering processes.

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Problems of TL dating of the mesopleistocene loess deposits in the Podillya and Pokuttya regions (Ukraine)

Kusiak J., Łanczont M., Madeyska T., Bogucki A. B.

Geochronometria

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2013

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Vol. 40, no. 1

51-58

EN

In many papers different authors was described problem of systematic underestimation of TL ages for sediments older then 100 ka. We presented the results which probably are not significant-ly rejuvenated. This is another example of the TL dates made in Lublin laboratory which are likely in agreement with the stratigraphic interpretation. In 2002 Kusiak et al. published the TL ages ranging from 200 to 800 ka for the Zahvizdja loess profile in Ukraine. These first promising results of TL da-ting of so old deposits encouraged us to undertake further studies. In next years were discovered other Ukrainian loess profiles with the Middle and Lower Pleistocene deposits, among others in the Skala Podils’ka, Mamalyha and Vendychany sites. The thermoluminescence dating made for these profiles in the Lublin laboratory gave the next, after Zahvizdja, series of 15 TL ages ranging from 200 to 700 ka. This way we confirmed the possibility of TL dating of the deposits older than 400 ka BP.

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New exposure of loess deposits in Boyanychi (Ukraine) - results of thermoluminescence analyses

Kusiak J., Łanczont M., Bogucki A. B.

Geochronometria

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2012

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Vol. 39, no. 1

84-100

EN

The loess site at Boynychi (the Volyn Upland) is of essential importance for the stratigra-phy of Middle and Upper Pleistocene in Central Europe. The profile was recently dated by Fedorowicz and Prylypko in 2007 (parallel dating), and by Kusiak in 2009. The Upper Vistulian loesses are much thicker in the exposure from 2009 than in the earlier examined one (2007). The list of results obtained in the Gdańsk, Kiev and Lublin laboratories, respectively, can be divided in two. The first group contains the results obtained for the Horohiv and Korshiv pedocomplexes and for the loess from the penultimate glacial, which separates these pedocomplexes. The results from all laboratories are very similar and rather well describe the real age of dated deposits. The second group contains the widely differing results of dating of the Vistulian loesses. The TL ages obtained by Fedorowicz and Prylypko are considerably older than those obtained by Kusiak in the new exposure. The latter ones excellently correspond to the geologic-stratigraphic interpretation of the profile. Two incompatible se-ries of TL dating results indicate that local variability of loess accumulation conditions in different stages of their formation may have resulted in incomplete luminescence zeroing of mineral material before deposition.