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Patterned‐ground landforms represent the most common phenomenon of periglacial environment, and their large sorted forms belong to the few morphological indicators of past permafrost distribution. The relic forms of patterned ground are widespread on high‐elevated surfaces in the central European uplands, providing the evidence of regional periglacial conditions in the last glacial period. However, the timing of these landforms, as well as their potential for paleoclimate reconstructions, has remained unexplored. In this paper, we present 10Be exposure ages from the large sorted polygons sampled at four sites in the Sudetes Mountains, the highest part of the central European uplands. These results indicate that these landforms started to form at the end of Marine Isotope Stage 3, and the main phase of their formation occurred between 30 and 20 ka. This research confirms the hypothesis of sorted patterned‐ground formation within the last (Weichselian) glacial stage (110.6–11.7 ka) and suggests that earlier‐sorted features are not preserved in the Sudetes. The recognized period of enhanced periglacial activity coincides with a prominent cold interval identified earlier in both regional and northern‐hemispheric proxy records. [ABSTRACT FROM AUTHOR]

The Jizerské hory Mountains in the Czech Republic have traditionally been considered to be a highland that lay beyond the limits of Quaternary glaciations. Recent work on cirque-like valley heads in the central part of the range has shown that niche glaciers could form during the Quaternary. Here we report geomorphological and sedimentary evidence for a small glacier in the Pytlácká jáma Hollow that represents one of the most-enclosed valley heads within the range. Shape and size characteristics of this landform indicate that the hollow is a glacial cirque at a degraded stage of development. Boulder accumulations at the downslope side of the hollow probably represent a relic of terminal moraines, and the grain size distribution of clasts together with micromorphology of quartz grains from the hollow indicate the glacial environment of a small glacier. This glacier represents the lowermost located such system in central Europe and provides evidence for the presence of niche or small cirque glaciers probably during pre-Weichselian glacial periods. The glaciation limit (1000 m asl) and paleo-ELA (900 m asl) proposed for the Jizerské hory Mountains implies that central European ranges lower than 1100 m asl were probably glaciated during the Quaternary. [ABSTRACT FROM AUTHOR]

Relict periglacial sorted nets are valuable indicators of past permafrost and climate states, but their field studies are usually challenging due to high time requirements and poor visibility. This study therefore tests the suitability of high-resolution digital elevation model and aerial photographs with a horizontal resolution of 0.5 m and 0.2 m, respectively, to map and analyse the geometry of 2000 sorted nets from the Last Glacial Period at one site in the Krkonoše Mts., Czech Republic. Since the sorted nets occupy an area of ∼1.79 ha, the density of their network accounts for ∼1117 cells per hectare. The sorted nets have a mean diameter of 3.46 ± 0.83 m, a mean height of 0.28 ± 0.10 m, and a mean estimated sorting depth of 0.94 ± 0.22 m. The number of sides ranges between three and ten, but averages 5.99 ± 1.13, and 83.4 % of the sorted nets are pentagonal to heptagonal, and their sides mostly meet at three-way junctions at a mean angle of 119.9 ± 25.6°. However, isometric sorted nets are rather rare as a length-to-width ratio attains 1.47 ± 0.28. The estimated sorting depth indicates that permafrost superimposed by ∼1 m thick active layer occurred at the study site at the end of the Last Glacial Period. Generally, the remotely sensed parameters of the sorted nets are consistent with field data previously collected at the same study site and literature reports including those on past regional environmental conditions. This proves the utility of the high-resolution airborne data to map and analyse the geometry of large sets of sorted patterns, which would be difficult in conventional field surveys. Consequently, remote sensing could bring a wealth of new information on sorted patterned ground and its characteristics from past and present periglacial landscapes, and aid in past permafrost and climate modelling. The collected dataset of the parameters of the sorted nets could also have many other applications such as for choosing an effective sample size or the minimum network size to be included in statistical comparisons in future patterned-ground surveys, and for validating automated mapping and/or delineation tools and models of patterned-ground growth. • Last glacial sorted nets were examined using high-resolution (<0.5 m) airborne data. • Length, width, and diameter of sorted nets differ by <13 % from ground-truth data. • Height of sorted nets is ∼35 % lower compared to ground-truth data. • Sorted nets developed within ∼1 m thick active layer over permafrost. • At least ∼30–100 sorted nets need to be sampled for their parameter errors <5 %. [ABSTRACT FROM AUTHOR]

10 Be exposure ages from moraines and bedrock sites in the Roháčská Valley provide chronology of the last glaciation in the largest valley of the Western Tatra Mts., the Western Carpathians. The minimum apparent exposure age of 19.4 ± 2.1 ka obtained for the oldest sampled boulder and the mean age of 18.0 ± 0.8 ka calculated for the terminal moraine indicate that the oldest preserved moraine was probably deposited at the time of the global Last Glacial Maximum (LGM). The age of this moraine coincides with the termination of the maximum glacier expansion in other central European ranges, including the adjacent High Tatra Mts. and the Alps. The equilibrium line altitude (ELA) of the LGM glacier in the Roháčská Valley, estimated at 1400–1410 m a.s.l., was 50–80 m lower than in the eastern part of the range, indicating a positive ELA gradient from west to east among the north-facing glaciers in the Tatra Mts. Lateglacial glacier expansion occurred no later than 13.4 ± 0.5 ka and 11.9 ± 0.5 ka, as indicated by the mean exposure ages calculated for re-advance moraines. This timing is consistent with the exposure age chronology of the last Lateglacial re-advance in the High Tatra Mts., Alps and lower mountain ranges in central Europe. The ELA in the Roháčská Valley estimated at 1690–1770 m a.s.l. in this period was located 130–300 m lower than in the north-facing valleys in the High Tatra Mts. 10 Be exposure ages obtained for a rock glacier constrains the timing of this landform stabilization in the Salatínska Valley and provides the first chronological evidence for the Lateglacial activity of rock glaciers in the Carpathians. [ABSTRACT FROM AUTHOR]