Low to middle Pleistocene paleoclimatic record from the Kraków-Częstochowa Upland (Poland) based on isotopic and calcite fabrics analyses

Abstract

The quality of paleoenvironmental reconstruction based on speleothem records depends on the accuracy of the used proxies and the chronology of the studied record. As far as the dating method is concerned, in most cases, the best solution is the use of the U-series method to obtain a precise chronology. However, for older periods (i.e., over 0.5 Ma), dating has become a serious challenge. Theoretically, older materials could be dated with the U-Pb dating method. However, that method requires a relatively high uranium content (minimum of several ppm), whereas typical speleothems from Poland (and all of Central Europe) have uranium concentrations below 0.1 ppm. Because the materials in Polish caves are problematic, we applied oxygen isotope stratigraphy (OIS) as a tool for speleothem dating. By using OIS as an alternative tool to create a chronology of our flowstone, it was found that the studied flowstone crystallized from 975 to 470 ka with three major discontinuities, so obtained isotopic record can be correlated with oxygen isotopic stages from MIS 24 to MIS 12. The observed isotopic variability was also consistent and confirmed with the petrographic observations of the flowstone.

Geotouristic attractiveness of the show caves of the Kraków-Częstochowa Upland area

“…By using oxygen isotope stratigraphy (OIS) method, it was found that this flowstone crystallizing process was dated between 935 ±5 ka -470 ±5 ka with three major discontinuities. The observed isotopic variability was also consistent and confirmed with the petrographic observations of the flowstone (Błaszczyk et al, 2018). The visitors come back to the entrance opening by the same way (Fig.…”

Speleothem Records from the Eastern Part of Europe and Turkey—Discussion on Stable Oxygen and Carbon Isotopes

“…An explanation for this is that the permafrost conditions prevailed around [57] and beneath [58] the former Fennoscandian Ice Sheet, thereby preventing speleothem growth [17] because there was no water movement in the frozen ground. This hypothesis is indirectly supported by a recent study showing flowstone deposition in the Kraków-Częstochowa Upland at 975-470 ka BP [59]), predating the major glaciations in the region. The thawing of this frozen ground could be a prolonged process after deglaciation [60], maintaining unfavorable conditions for speleothem formation.…”

“…In addition, there is a good chance to further extend the regional dataset beyond MIS 6, as records predating the ones in SISAL_v1 have already been identified from Turkish [69], Macedonian [51], Croatian [78] and Hungarian [79] localities. Moreover, calcareous cave deposits exceeding the current limit of applicability of U-Th dating method (~600 kyr) and for which U-Pb dating methods [80,81] could be applied, have been found in the region [59]. The average length of the records is ~13.8 kyr and the median is 4.9 kyr, including hiatuses.…”

Speleothem Stable Isotope Records from Eastern Europe & Turkey

“…One explanation for this is that the permafrost conditions which existed around [56] and beneath the former Fennoscandian Ice Sheet which covered this area [57] very likely prevented speleothem formation (see also [23]) of because there was no water movement in the frozen ground. This hypothesis is indirectly supported by a recent study showing flowstone deposition in the Kraków-Częstochowa Upland at 975-470 ka [58]), predating the major glaciations of the region. The thawing of this frozen ground could be a prolonged process after deglaciation [57,59], maintaining unfavorable conditions for speleothem formation.…”

“…Croatian [70] and Hungarian [71] localities. Moreover, calcareous cave deposits exceeding the current limit of applicability of U-Th dating method can be found in the region [58]. However, recently this knowledge-gap began to be filled by speleological monitoring studies becoming abundant in the region [10,[74][75][76][77][78][79][80].…”