Frequency distribution of radiocarbon dates as a tool for reconstructing environmental changes

Large sets of radiocarbon dates of 1019 peat, 155 speleothem, and 100 tufa samples, as well as dates of 330 flu-vial samples, were investigated in order to estimate environmental variability during the last 16,000 calendar years in Poland. All ¹⁴C dating was carried out in the Gliwice Radiocarbon Laboratory, and results are stored in the RoS database. Probability density functions (PDFs) were created by summing up (on the calendar timescale) individual age probability distributions of all dates for different types of material and for different regions of Poland. We used an updated version of the Gliwice Radio-carbon Laboratory calibration program GdCALIB. The ¹⁴C dates were calibrated using the IntCal04 calibration curve (Reimer et al. 2004), and results were compared with other paleoenvironmental records. The authors conclude that analyzing PDFs of different types of sediments can be helpful in the qualitative reconstruction of the past environment. The PDF for peat samples primarily reflects paleohydrological conditions; the PDFs for speleothem and tufa samples reflect changes in tem-perature and humidity, while analysis of the PDF created for fluvial data is in a general agreement with the PDFs constructed for peat samples.