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The sedimentary sequence of La Narce du Béage Basin is one of the few natural archives covering the last 18 ka cal. BP in the French Massif Central. This paper focuses on the palaeoecological reconstruction of environmental and climatic changes affecting this shallow periglacial lake from the Late-Glacial to the Early Holocene. After field surveys and geophysical mapping, two cores (cores A and D) were extracted and dated. Plant macrofossils, pollen, non-pollen palynomorphs (NPPs) and diatom assemblages were compared within the cores to study vegetation, temperature, pH, water level and ice cover changes through time. During the Oldest Dryas (18–14.75 ka cal. BP), climatic conditions were the coldest with a short ice-free season allowing the development of periphytic diatoms only (ecologically comparable to Arctic ones). A cold and dry steppe landscape – exposed to severe erosion – comprised an herbaceous and shrub flora (e.g. Artemisia , Chenopodiaceae, Helianthemum, Ephedra, Hippophaë, Juniperus). Animal presence is suggested by coprophilous fungi. Periphytic diatoms and allochtonous pollen (Cedrus) underline windy conditions, and the possible erosion of neo-formed soils. Then, during the Bølling-Allerød interstadial (14.75–12.7 ka cal. BP), the ice-free season increased and some trees/shrubs (Salix, Betula and Juniperus) established locally within open grasslands. During the Younger Dryas (12.7–11.7 ka cal. BP) cooler conditions favoured steppe taxa again (Helianthemum, Achillea, Artemisia , Caryophyllaceae, Ranunculaceae) and erosion increased. The ice cover on the lake prevailed even if the conditions were not as cold as during the Oldest Dryas. During the Preboreal (11.7–10 ka cal. BP) Isoëtes echinospora and I. lacustris developed in the eulittoral zone of the lake, which was surrounded by a swamp forest (with Betula nana and B. pubescens). Pinus sylvestris, Betula pendula, Corylus avellana and trees from the Quercetum mixtum rapidly established in the uplands. Occurrences of Gaeumannomyces and Xylomyces fungi – both phytopathogens on broadleaved trees – and decreasing herb values indirectly hint at a close forest canopy. At the beginning of the Boreal (10 ka cal. BP), aquatic and semi-aquatic taxa developed on open water due to longer ice-free seasons (diatoms, micro-algae, Alisma plantago-aquatica, Potamogeton, Typha). The final terrestrialization towards a mire occurred as a consequence of the Holocene warming and related to water chemistry changes (acidification, eutrophication). • During the last deglaciation, a very shallow lake established as demonstrated by palaeoecological data, such as epiphytic diatoms, living on rocks. • Late-Glacial steppe landscape with severe erosion, open grassland and possible mega-herbivore presence. Arctic-like conditions. • Development of shrubs or trees during the Bølling-Allerød interstadial and reduced ice-free season. • Dry and cold conditions persisted from the Younger Dryas to the Early Preboreal. Oligotrophic flora (Isoetids) established in the eulittoral zone. • During the post-glacial warming, the lake tended to acidify. Peat flora and organic matter accumulated and led to the terrestrialization of the lake. [ABSTRACT FROM AUTHOR]

In this study, we present the full sequence of Eemian succession from the Kozłów palaeolake – one of the key sites for Eemian Interglacial in this part of Poland. In the paper, previous palynological and diatom assessments were supplemented by further pollen, Cladocera and macrofossil analysis. This enabled detailed reconstruction of a palaeolake functioning under changes of climate and other environmental conditions during MIS 5e. All identified alterations of trophy, depth and aquatic vegetation within the reservoir point to dynamic changes in early stages of lake functioning, relatively stable conditions in mid-Eemian and gradual lake shallowing starting from Caprinus phase. Thus, Kozlów palaeolake joins the noble group of sites with exceptionally well-recognized multi-proxy records of the Eemian Interglacial environment, and has the potential to become a benchmark for this part of Europe. [ABSTRACT FROM AUTHOR]

This paper presents an overview of the results obtained by collaborative use of integrative multidisciplinary investigation of a highly unique geological section discovered in the south-eastern part of the Gulf of Finland. The main aim of this study is to identify the Late Pleistocene palaeoenvironmental and palaeoclimatic changes in the study area during one of the most controversial periods in the Late Pleistocene history, which is the MIS 5. Our approach to achieving the goal is based on the investigation of feldspar-based infrared optically stimulated luminescence (IR-OSL) dated records of pollen-induced palaeoclimate and palaeoenvironmental proxies. Palynological analysis and IR-OSL dates of 29 samples for the first time produced a detailed, characterised and dated sequence of palynological zones M6 to M8 ranging from ca. 94 ka to ca. 70 ka and made it possible to determine the chronological sequence of climate changes in this interval. Representative pollen spectra from 69 samples provided convincing evidence of a warm interval of interglacial rank at least during the latter half of MIS 5. The data obtained in the present study from well-preserved deposits of the second half of MIS 5 provided a novel insight into the palaenvironmental conditions during this period. These results seem to contradict the widely held view according to which the last interglacial stage with the climate conditions similar or warmer than today corresponds to only a small part of marine isotope stage (MIS) 5 of the deep-sea stratigraphy, i.e. MISs 5e lasting ca. 11 ka, and the period from 100 ka to 80 ka is attributed to an Early Weichselian glaciation, which in Northern Eurasia reached its maximum at about 90 ka. However, the findings obtained during the present study are also convincingly confirmed by those of our previous long-term investigations of warm climate-related shell-bearing deposits of various origins from Northern Eurasia including climatically highly sensitive Eurasian Arctic palaeo-shelf area. These results indicated that the overwhelming majority of the warm climate-related dates (ca. 82%) is also concentrated in the latter half of MIS 5 in the time range between 110 ka and 70 ka. [ABSTRACT FROM AUTHOR]

In addressing the controversial issues of the Late Pleistocene paleogeography of the Caspian basin, an important role is given to the results of the spore-pollen analysis and based on them reconstructions of climate and vegetation changes in the Northern Caspian region during the development of the Early Khvalynian transgression. In this paper we present the main results of the palynological study of deposits (chocolate clays and the overlying and underlying layers from the Srednyaya Akhtuba section) of maximum stage of the Early Khvalynian transgression; the materials are illustrated by pollen diagram with the data of spore-pollen analysis and the detailed list of palynoflora recovered from the studied Lower Khvalynian sequences, and complemented with photographs of pollen belonging to the principal autochtonous taxa and, for comparison, to some redeposited palynomorphs. Palynological materials indicate subaqual (brackish marine and freshwater) sedimentation of the sediments studied in periglacial landscapes and, for the most part, under very harsh climatic conditions. The performed climate-stratigraphic reconstructions do not contradict the data of absolute dating on the accumulation of the studied deposits during the Late Valdai (Ostashkov) late Glacial period. During this interval in the territory of the study area, plant communities of the glacial climate — tundra-steppe, periglacial forest-steppe, periglacial steppe, periglacial parklands and periglacial forests — were developed. The widespread occurrence in the composition of the periglacial vegetation cover of the studied region of the yernik formations from Betula nana and shrub communities from Betula fruticosa , B. nana , Alnaster fruticosus , Juniperus , etc. testifies to the severe climatic conditions and, possibly, the existence of sporadic permafrost in the cold stages (stadials) of the Ostashkov Late Glacial period. [ABSTRACT FROM AUTHOR]