Buried Late Weichselian thermokarst landscape discovered in the Czech Republic, central Europe

0523792 - ARÚB 2020 RIV US eng J - Journal Article
Hošek, J. - Prach, J. - Křížek, M. - Šída, Petr - Moska, P. - Pokorný, P.
Buried Late Weichselian thermokarst landscape discovered in the Czech Republic, central Europe.
Boreas. Roč. 48, č. 4 (2019), s. 988-1005. ISSN 0300-9483. E-ISSN 1502-3885
Institutional support: RVO:68081758
Keywords : termokarst * late glacial * paleolake * palynostratigraphy * permafrost
OECD category: Archaeology
Impact factor: 2.477, year: 2019
Method of publishing: Limited access
https://onlinelibrary.wiley.com/doi/abs/10.1111/bor.12404

Pronounced climatic warming associated with the Late Weichselian Pleniglacial-to-Lateglacial transition caused considerable environmental changes throughout the former periglacial zones (in Europe ~53°–46°N). During permafrost degradation and subsequent ground subsidence (i.e. thermokarst processes), the landscape changed rapidly. In this study we investigated a flat mid-altitude area in south Bohemia, Czech Republic, lying close to the southern limit of the Weichselian permafrost. We discovered palaeo-lake basins with sedimentary infillings up to 11 m in depth. According to radiocarbon and palynostratigraphical dating, these basins were formed at the onset of the Late Pleniglacial-to-Lateglacial transition, whereas the smaller depressions were formed later. We suggest that the basins resulted from thermal and fluvio-thermal erosion of the former permafrost and represent remnants of discontinuous gullies and possibly collapsed frost mounds (pingo/lithalsa scars). The formation of this a fossil thermokarst landscape was climatically driven and multiple phased, with the major phase during the climatic warming and wetting at the onset of GI-1e (Bølling) and the minor phase during GI-1c (Allerød). This study enhances knowledge of the palaeogeography of the former European periglacial zone by showing that Late Pleistocene thermokarst activity could have had a significant impact on the evolution of the landscape of at least some regions of central Europe along the southern limit of the continuous permafrost zone. The research also points to a similar history for the physical transformation of the landscape of the former European periglacial zone and current thermokarst landscapes and could be a valuable source of information with respect to the future transformation of the Arctic under conditions of ongoing global warming.
Permanent Link: http://hdl.handle.net/11104/0308085