Palaeoenvironmental Proxies for Permafrost Presence During the Younger Dryas, Central Poland

Abstract

Involutions and small frost fissures have been recorded over a wide area of the lower terrace of the Warta River valley (central Poland). They developed at the lithological boundary between an organic‐rich deposit with a thin peat layer (unit b) and an underlying fluvial sandy deposit (unit a). Most of the involutions are products of a reversed density gradient and loading, or developed under the influence of cryohydrostatic pressure. Among them are drop‐like and flat‐bottomed structures, diapirs, flame‐like and fold structures and irregular involutions. Some frost fissures have also been recorded in the same stratigraphic position. The sedimentological properties and formative mechanism of the involutions, together with environmental data (lithology, groundwater conditions, snow cover and vegetation), reveal their origin as periglacial. Radiocarbon dating indicates that the structures formed during the Younger Dryas. Overall, the involutions and frost fissures indicate that permafrost re‐aggraded in this region of central Poland during the Younger Dryas. Copyright © 2017 John Wiley & Sons, Ltd.

Small-scale geologic evidence for Vistulian decline cooling periods: case studies from the Łódź Region (Central Poland)

“…In the Łódź Region, involutions connected with the Vistulian decline cold intervals were described from: soil horizons (Jurkiewiczowa, 1961); both dunes (Chmielewski, 1970;Twardy, 2008) and coversands (Goździk, 1973) for aeolian environments; and the boundary between sandy-silty series (deposit of mixed fluvio-aeolian-slope origin) and dune sands (Kasse et al, 1998). The best recognized involutions of the Younger Dryas age occur in the Warta River valley, where they were studied over a wide area of the brown-coal open pits and their development under frozen ground conditions has been proven (Petera, 2002;Petera-Zganiacz, 2016;Petera-Zganiacz & Dzieduszyńska, 2017). The present study completes the picture of the recognized inventory of such structures (Figs.…”

“…Interesting and significant features, which grew in the Younger Dryas cold interval, are icewedge casts, ~3 m deep and ~0.2 m wide and small narrow sand wedges described from the base of the aeolian dune sands in the Bełchatów brown-coal open pit (Kasse et al, 1998). In the Adamów brown-coal open pit, frost fissures were reported from fluvial sediments (Petera-Zganiacz & Dzieduszyńska, 2017). The structures are 1.5 m long and only up to a few centimetres wide, and filled with sand in the bottom, host deposits in the middle, and overlying material in the top.…”

“…According to the most common opinion, in the northwestern continental and central European territory, the ultimate permafrost disappearance took place during the Alleröd (Böse, 1995;Kozarski, 1996;Goździk, 1996;Klatkowa, 1996;Marks, 1996). Recently, based on studies in peatbogs of the Łódź Region, Petera-Zganiacz & Dzieduszyńska (2017) have proven that the permafrost re-aggraded locally in the Younger Dryas.…”

“…In a similar geologic setting, small involutions were documented in the south part of the studied Warta valley section. During previous studies, six types of involutions had been distinguished (Petera-Zganiacz & Dzieduszyńska, 2017), and, in terms of their features, deformations described at the Kwiatków DJ site allow them to be classified as the diapiric type in the lower organic layer and the diapiric and flame-like involution type in the upper horizons. As with the other nearby sites, the age of the disturbed sediment and the comparable palaeogeographic conditions in which the involutions developed both indicate that they were formed in the periglacial environment of the Younger Dryas, which provides evidence of cold climate influencing sediment transformation during the Vistulian decline.…”

Typical Soft–Sediment Deformation Structures Induced by Freeze/Thaw Cycles: A Case Study of Quaternary Alluvial Deposits in the Northern Qiangtang Basin, Tibetan Plateau

“…Cryogenic wedges are the most common and typical deformation structure in periglacial environments (Vandenberghe, 1988;Jin et al, 2016), and are often used as direct evidence of freeze/thaw cycles. Much attention has consequently been paid to the criteria used to recognize SSDS caused by freeze/thaw cycles (Vandenberghe, 1988(Vandenberghe, , 1992van Vliet-Lanoë et al, 2004;Vandenberghe et al, 2016;Petera-Zganiacz and Dzieduszyńska, 2017), but few studies have compared SSDS due to seismic activity with those due to freeze/ thaw cycles.…”