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Abstract

The present study is an attempt to utilise the uranium-thorium dates ofspeleothems as a source ofpalaeoclimatic data. The clue is that the changing climate influenced intensity of speleothem deposition, which is reflected in clustering of U-Series dates of speleothems in certain time intervals. This work discusses and improves various methods of combined presentation of dates, with a special attention to the presentation in form of growth frequency ('pdf) curves. Using the 'bootstrap' method the confidence intervals of the 'pdf' curves could be determined. Also the algorithm, originally developed to determine parameters of arbitrarily chosen maxima in the curve, has been modified. Due to that an assessment of number of maxima has been possible. This method enables objective distinction of phases of speleothem growth, which cannot be done 'by eye' when the 'pdf' curve is smooth. The statistical tests show that the reliable 'pdf' curve should contain more than 150 dates. Basing on 308 U-series dates of cave speleothems from southern Poland and other regions of central Europe, the growth frequency curves for the Carpathians and Uplands have been constructed. Comparison of phases of speleothem growth, distinguished by various authors for several regions of Europe, indicates that the climatic changes were synchronous over the whole region. However, different shapes of the 'pdf' curves reflect increasing continuity ofspeleothem growth in the N-S transect southwards. This may be connected with the N-S climatic gradient in Europe. Using the 'pdf' curves from caves of Tatra and Low Tatra Mountains the most probable timing of development phases of mountain glaciers has been delimited.
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Authors and Affiliations

Helena Hercman
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Abstract

The objective of this paper is a review of data on reconstruction of the Pleistocene palaeogeography (environment) and stratigraphy based on studies of karst sites in the Świętokrzyskie (Holy Cross) Mountains. Although the number of known Pleistocene karst sites in this region is small, the investigations of them have played a crucial role in a research of the Pleistocene. The study of the Kozi Grzbiet site provided the first evidences for new climatostratigraphy and classification of glaciations in Poland. The explanation of genesis of cryogenic calcite crystals discovered in Chelosiowa Jama-Jaskinia Jaworznicka cave system started a new direction of palaeoenvironmental reconstructions of the last glacial period. Kadzielnia palaeontological site was one of the first Early Pleistocene fossil assemblages in karst studied in Poland, whereas Raj cave provided abundant palaeontological and archaeological material from the Last Glacial. Other sites are of less scientific importance, however some of them can be used in education and popularisation of geosciences. Small number of already studied sites does not exclude discoveries of next sites of high scientific importance.

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Authors and Affiliations

Jan Urban
Helena Hercman
Katarzyna Ochman
Andrzej Kasza

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