Jan Hošek

• PhD
• Geologist at Czech Geological Survey

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...

Geoarchaeological investigations on the northeastern shore of Lake Ohrid revealed 3.5 m thick deepwater lacustrine sediments overlying terrestrial vegetation macrofossils, worked wood and abundant potsherds dated to the Late Bronze Age (LBA). Distinct contact of deepwater sediment with the sub-aerial weathered limestone bedrock point to a sudden in...

Knowledge of past environmental change and prehistoric settlement dynamics in the Sahel east of the Nile is limited due to the scarcity of suitable sedimentary archives and archaeological sites. Here we present tufa-based paleoenvironmental records from the area of NW Butana (central Sudan, ∼55 km southeast of the Nile River) which show that increa...

Northern glacial refugia are a hotly debated concept. The idea that many temperate organisms survived the Last Glacial Maximum (LGM; ~26.5 to 19 thousand years) in several sites across central and northern Europe stems from phylogeographic analyses, yet direct fossil evidence has thus far been missing. Here, we present the first unequivocal proof t...

The first discovery of prehistoric human remains at the same wetland as millet plants ( Panicum miliaceum ), which is reported here for the Zahájí site in the Czech Republic, sheds curiously new light on the central European Middle Bronze Age. The millet and a human fingernail (both dated ca. 1400–1300 BC) were found in what was possibly a newly fo...

The landscape of central Europe is thought to have been dominated by steppe, forest-steppe, or tundra during the Last Glacial. This classical view is mostly based on the pollen records. However, as the pollen production and taphonomy during the cold periods are largely unknown, modern analogies of past landscapes need to be involved to provide more...

The authors present preliminary results from a new research project based in Jebel Shaqadud, Sudan. Their findings highlight the potential for this region's archaeological record to expand our understanding of the adaptation strategies used by human groups in arid north-east African environments away from rivers and lakes during the Holocene. Furth...

2021) Interdisciplinary geoscientific approach to radioactive waste repository site selection: the Březový potok site, southwestern Czech ABSTRACT Interpretation of the deep geological and tectonic setting is a key step for safety assessment of the potential sites for a deep geological repository of radioactive waste. However, the conventional geol...

We present a new chironomid record from sediments of former Lake Švarcenberk in South Bohemia (412 m asl, Czech Republic), located in the oceanic-to-continental macroclimatic transitional zone of eastern Central Europe. We provide estimates of Weichselian Late Glacial and Early Holocene (ca. 15–8 ka BP) mean July air temperatures on the basis of ch...

Paleoenvironmental reconstructions on a (supra-)regional scale have gained attention in Quaternary sciences during the last decades. In terrestrial realms, loess deposits and especially intercalations of loess and buried soils, so called loess-paleosol sequences (LPS) are important archives to unravel the terrestrial response to e.g. climatic fluct...

The presented study deals with unusual geomorphological features discovered within the aeolian sand belt along the Morava River in southern Moravia (Czech Republic), situated on the northernmost margin of the Vienna Basin (Fig. 1). Geological substrate is represented by poorly permeable sandy clay belonging to the Upper Miocene (Bzenec and Dubňany...

Millennial-scale palaeoclimate variability has been documented in various terrestrial and marine palaeoclimate proxy records throughout the Northern Hemisphere for the last glacial cycle. Its clear expression and rapid shifts between different states of climate (Greenland Interstadials and Stadials) represents a correlation tool beyond the resoluti...

A set of two maar craters (Ztracený rybník and Bažina) was newly identified in Western Bohemia. The two new volcanic geomorphologic features are located on the western uplifted shoulder of the Cheb-Domažlice Graben (Fig. 1). With respect to other small preserved monogenetic volcanoes aligned along the Tachov Fault (Fig. 1), a Pleistocene age has al...

The Late Glacial (LG; ~16–11.7 ka BP) is characterized by rapid and pronounced climatic oscillations and distinct environmental changes throughout the former periglacial zones. Although the effects of these climatic events have been well documented using paleobiological methods (especially in lacustrine and organic sediments), our knowledge of the...

Supraregional (palaeo)geoecological studies require detailed knowledge of the distribution of aeolian sediments and their sources. Such spatial data can be visualised and shared in maps, but often these are constrained in their resolution or extent. This is the case for the Carpathian Basin, where cross-border maps are not detailed enough to answer...

Thermokarst is a geomorphologic/genetic designation for areas where thawing of permafrost leads to local or widespread collapse, subsidence, erosion, and instability of the ground surface. Although thermokarst processes are recently peculiar to regions underlain by permafrost, i.e. in particular to lowlands of high latitudes Arctic areas (Alaska, C...

Millennial scale climate variability is seen in various records of the northern hemisphere for the last glacial cycle. Their expression represents a promising stratigraphic correlation tool beyond the temporal resolution of numerical dating, e.g. luminescence dating. Highest (correlative) dating accuracy is a prerequisite of comparing different geo...

While general trends in Central European postglacial recolonisation dynamics are relatively well known, we often lack studies on intermediate (meta-population, landscape) scales. Such studies are needed to increase our understanding of, for example, the location of refugia; emergence of endemism, rates and trajectories of postglacial migrations; an...

The Middle Pleniglacial on the northern hemisphere is characterized by millennial scale, frequent, and high amplitude environmental climatic shifts. In loess-paleosol sequences (LPSs) the transition from the Lower (MIS 4) to the Middle Pleniglacial (MIS 3) was accompanied by significant erosion events, as recorded in various terrestrial archives ac...

Results of the project "Mongol Altai-50" of the Czech Development Cooperation with Mongolia, were successfully defended before the Mongolian Stratigraphic Commission in September 2016, in Ulan Bator. The project was carried out during 2013–2016, and experts from four countries participated in its implementation. The project was located in western M...

While lake deposits are commonly abundant in northern and NW Europe, most of the central Europe (except for the Alpine piedmont and Panonnian basin) is rather poor in this respect. This very much holds for the territory of the Czech Republic, where the absence of lacustrine deposits is explained both by the high relief dynamics of the region and by...

This article presents the results gathered during geological mapping of the northern part of the Vienna Basin. During this investigation the fluvial terracess of the rivers Morava and Dyje were found to belong to the Middle Pleistocene period with their bases at relative altitudes of 15–22 and 0–2 above the floodplain surface (the so-called the mai...

In the frame of the project of Czech International Development Cooperation Geological mapping and mineral prospecting at a scale of 1:50 000 in the selected part of Western Mongolia geological surveying continued last year in the districts of MunkhKhairkhan, Manchan and Zereg. Cenozoic (Quaternary and Neogene) sediments of this part of Mongolian Al...

Under the water surface of the Velký Tisý fishpond and in its surrounding, four depressions were discovered by hand boring. Size of the depressions is several tens up to several hundred meters in diameter and they are filled by peat and thick lake sediments, which accumulated during the Late Glacial and Early Holocene. Pre-Holocene age of the depos...

The Middle and Upper Palaeolithic sites situated within the system of Moravian and South Silesian valleys are key localities for understanding the patterns of seasonal mobility that enabled humans to exploit the North European Plain, and a possibility to distinguish the importance of the weather and climate for their subsistence practises. Loess ac...

During 2010–2012 years, four new geological sections were documented at Pavlov (district Bøeclav). Studied sections are composed of macroscopically identified several soil horizons separated by loess, loess derivatives and colluvial sediments. Nevertheless, based on micromorphology, the paleosols have not been formed in situ, but they represent soi...