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Samoylov Island is centrally located within the Lena River Delta at 72° N, 126° E and lies within the Siberian zone of continuous permafrost. The landscape on Samoylov Island consists mainly of late Holocene river terraces with polygonal tundra, ponds and lakes, and an active floodplain. The island has been the focus of numerous multidisciplinary studies since 1993, which have focused on climate, land cover, ecology, hydrology, permafrost, and limnology. This paper aims to provide a framework for future studies by describing the characteristics of the island's meteorological parameters (temperature, radiation, and snow cover), soil temperature, and soil moisture. The land surface characteristics have been described using high resolution aerial images in combination with data from ground-based observations. Of note is that deeper permafrost temperatures have increased between 0.5 to 1 °C over the last five years. However, no clear warming of air and active layer temperatures is detected since 1998, though winter air temperatures during recent years have not been as cold as in earlier years. [ABSTRACT FROM AUTHOR]

Soils are an important compartment of ecosystems and have the ability to immobilize chemicals preventing their movement to other environment compartments. Predicted climatic changes together with other anthropogenic influences on Arctic terrestrial environments may affect biogeochemical processes enhancing leaching and migration of trace elements in permafrost-affected soils. This is especially important since the Arctic ecosystems are considered to be very sensitive to climatic changes as well as to chemical contamination. This study characterizes background levels of trace metals in permafrost-affected soils of the Lena River Delta and its hinterland in northern Siberia (73.5° N-69.5° N) representing a remote region far from evident anthropogenic trace metal sources. Investigations on total element contents of iron (Fe), arsenic (As), manganese (Mn), zinc (Zn), nickel (Ni), copper (Cu), lead (Pb), cadmium (Cd), cobalt (Co) and mercury (Hg) in di?erent soil types developed in di?erent geological parent materials have been carried out. The highest concentrations of the majority of the measured elements were observed in soils belonging to ice-rich permafrost sediments formed during the Pleistocene (ice-complex) in the Lena River Delta region. Correlation analyses of trace metal concentrations and soil chemical and physical properties at a Holocene estuarine terrace and two modern floodplain levels in the southern-central Lena River Delta (Samoylov Island) showed that the main factors controlling the trace metal distribution in these soils are organic matter content, soil texture and contents of iron and manganese-oxides. Principal Component Analysis (PCA) revealed that soil oxides play a signi?cant role in trace metal distribution in both top and bottom horizons. Occurrence of organic matter contributes to Cd binding in top soils and Cu binding in bottom horizons. Observed ranges of the background concentrations of the majority of trace elements were similar to background levels reported for other pristine arctic areas and did not exceed mean global background concentrations examined for the continental crust as well as for the world's soils. [ABSTRACT FROM AUTHOR]

This paper presents new data on Oligocene–Quaternary deposits, recent (Neogene–Quaternary) structures, and active faults of the northern side of the Ubsunur Basin at its boundary with the Tannu-Ola Ridge, based on structural interpretation of remote sensing (RSD) and field data (2020–2021), including trenching of active faults. Two parageneses of faults of different geological natures and structural and relief-forming significance were identified in the north of the Ubsunur Basin. The first paragenesis presented by the covered North Ubsunur thrust and related deformations that developed during Neogene–Quaternary and which formed the boundary of the depression and the mountain uplift. The second paragenesis includes the South Tannuol and Erzin-Agardag faults, which cut structures of the first paragenesis; these faults were being active in the Late Pleistocene and Holocene. [ABSTRACT FROM AUTHOR]

At present, there remains uncertainty surrounding the Younger Dryas-early Holocene glacial history of the Fennoscandian Ice Sheet in northwest Arctic Russia. This stems from a lack of high-resolution ice sheet-scale geomorphological data in the region. To address this, this paper presents 15,355 meltwater and morainic landforms in a new large-scale, glacial geomorphological map of the Younger Dryas-early Holocene ice marginal zone in the Republic of Karelia, northwest Russia. Individual landforms were mapped from relief-shaded renditions of the 2 m resolution ArcticDEM alongside 1 m resolution Esri World Imagery data in a Geographic Information System (GIS). The map, which is presented at a scale of 1: 675,000, will form the basis of a palaeo-glaciological reconstruction of northwest Russia that will inform on ice sheet dynamics – at both a regional- and ice sheet-scale – and provide an important framework through which numerical ice sheet models can be constrained. [ABSTRACT FROM AUTHOR]

Bog deposits that have existed for many thousands of years are valuable sources of information about changes in the Earth's climate in the past. One of the possible reasons for the change in the Earth's climate is the variations in solar radiation coming to the Earth's surface, due to the change in time of solar activity (SA). Thus, during the Little Ice Age (LIA), the well-known SA minima, the Spörer, Maunder, and Dalton minima, took place. This paper considers a possible relationship between changes in the growth rate of bog sediments and SA variations. In particular, it is shown that the decrease in the growth rate of bog deposits in the first millennium BC may be the result of a decrease in SA, which caused cooling on the Earth. [ABSTRACT FROM AUTHOR]

The paper studies sediments from Lake Tikozero that have accumulated successively in the littoral of Lake pre‐Imandra, Imandra lagoon, and an open lake isolated from a parental freshwater body. The 'Apatity' bog was concurrently formed on the Lake Imandra coast. Lithological, 14C, pollen and diatom data and findings of previous investigations provide the regional Holocene stratigraphy, which is subdivided into the early (c. 11 550–8200 cal a bp), middle (c. 8200–4000 cal a bp) and late (last 4000 cal a bp) Holocene sub‐stages. In the early Holocene, environments became favourable for diatoms after c. 9700 cal a bp. Birch phytocoenoses and pine forests with birch flourished in the area. In the middle Holocene, the west‐central Kola Peninsula was covered by a pine‐birch forest with alders. Lake Tikozero became shallow and desiccated in a warm and dry climate between c. 6300 and 4000 cal a bp; and a Sphagnum raised bog developed in the adjacent area, provoked by lowering of the water table. Spruce appeared in a pine‐birch forest and indicates a colder and wetter climate in the late Holocene. The flooding of Lake Imandra created a number of new small lakes; and fens occurred along the wet shores. [ABSTRACT FROM AUTHOR]

The paper presents isolation basin stratigraphy in bottom sediments from nine lakes in the Teriberka area on the Kola Peninsula, northwestern Russia. Isolation contacts in these basins, identified from lithological and diatom analysis, were used together with 25 radiocarbon dates, to construct a relative sea-level (RSL) curve for the Holocene. Records of marine water re-influx were found in the sediment sequence from one lake, located at c. 17 m a.s.l. The re-influx of marine water seems to be caused by the mid-Holocene (Tapes) transgression and tsunami event. The RSL curve indicates several phases in the postglacial evolution of the Kola coast. An early phase of rapid sea-level fall of c. 32 m around 11,500 cal yr BP, at a rate of c. 40 mm per year, corresponds to glacio-isostatically induced emergence following deglaciation at the Younger Dryas and beginning of the Holocene. In the time interval between c. 11,000 and 7600 cal yr BP, either a stillstand or a slight rise in relative sea level, cresting at about 21 m a.s.l., is suggested in the Teriberka area. This is followed, after c. 7300 cal yr BP to the present day, by a slow glacioisostatic emergence with an average rate of about 2–3 mm per year. [ABSTRACT FROM AUTHOR]

This paper presents two new pollen records and quantitative climate reconstructions from northern Chukotka documenting environmental changes over the last 27.9 ka. Open tundra‐ and steppe‐like habitats dominated between 27.9 and 18.7 cal. ka BP. Betula and Alnus shrubs might have grown in sheltered microhabitats but disappeared after 18.7 cal. ka BP. Although the climate was rather harsh, local herb‐dominated communities supported herbivores as is evident by the presence of coprophilous spores in the sediments. The increase in Salix and Cyperaceae ~16.1 cal. ka BP suggests climate amelioration. Shrub Betula appeared ~15.9 cal. ka BP, and became dominant after ~15.52 cal. ka BP, whilst typical steppe communities drastically reduced. Very high presence of Botryococcus in the Lateglacial sediments reflects widespread shallow habitats, probably due to lake level increase. Shrub Alnus became common after ~13 cal. ka BP reflecting further climate amelioration. Simultaneously, herb communities gradually decreased in the vegetation reaching a minimum ~11.8 cal. ka BP. A gradual decrease of algae remains suggests a reduction of shallow‐water habitats. Shrubby and graminoid tundra was dominant ~11.8–11.1 cal. ka BP, later Salix stands significantly decreased. The forest‐tundra ecotone established in the Early Holocene, shortly after 11.1 cal. ka BP. Low contents of green algae in the Early Holocene sediments likely reflect deeper aquatic conditions. The most favourable climate conditions were between ~10.6 and 7 cal. ka BP. Vegetation became similar to the modern after ~7 cal. ka BP but Pinus pumila came to the Ilirney area at about 1.2 cal. ka BP. It is important to emphasize that the study area provided refugia for Betula and Alnus during MIS 2. It is also notable that our records do not reflect evidence of Younger Dryas cooling, which is inconsistent with some regional environmental records but in good accordance with some others. [ABSTRACT FROM AUTHOR]

The dynamics of the last Fennoscandian Ice Sheet (FIS) are relatively well constrained in the Nordic countries. Ice‐sheet dynamics in NW Russia, however, are comparatively less well understood owing to the scale and resolution of existing studies. New large‐scale glacial geomorphological datasets from NW Russia based on high‐resolution remotely sensed imagery allow for an independent reassessment of the extent and dynamics of the FIS during the Younger Dryas and Early Holocene (c. 12.9–10 ka) in NW Russia. The reconstruction provides a more detailed link between geomorphological expressions of palaeoglaciation than previous proposals. Rather than a continuous Younger Dryas ice marginal zone (IMZ) stretching from Finland to northern Norway, the geomorphological signature of NW Russia reveals 14 IMZs that document discrete stationary ice‐margin positions (possibly standstill and/or readvance events) during the overall retreat. The relative age sequence of the IMZs, supported by an updated numerical age database, suggests that they formed time‐transgressively during the Younger Dryas and Early Holocene rather than contemporaneously. Moreover, specific landform assemblages reveal contrasting glacial landsystems in NW Russia: (i) a northern subpolar glacial landsystem; and (ii) a southern temperate glacial landsystem. The model presented herein provides robust empirical constraints for testing and validating numerical ice‐sheet models and understanding ice‐sheet responses to rapid climate change. [ABSTRACT FROM AUTHOR]

Peatlands store massive amounts of organic carbon, but the fate of this carbon remains unclear as global climate continues to warm. The age of peatland inception and the main drivers of peat initiation are one of the most important issues in Holocene paleoecology, especially for the numerous but under investigated peatlands in European Russia. This paper introduces new peatland initiation ages for 44 mires in three areas located in the central part of European Russia within the Polesie landscape belt. This region is characterised by waterlogged sandy plains and flat surface topography. Phases of peatland initiation were compared with Holocene fire regime derived from macro-charcoal data as well as with regional climatic reconstructions. We found that peat inception in the region started around 12,000 cal yr BP, but the most active phases of peatland initiation took place during the periods 8500–7500, 7000–6000, 5300–5800, 4000–3500 and 1700–1200 cal yr BP. Expect for rapid peat growth during the early Holocene, peatland initiation mostly coincided with warm climatic periods and increased fire frequency. Forest soil paludification in poorly drained Polesie landscapes was presumably enhanced by reduced evapotranspiration and changes in water balance due to disturbance of forest cover after wildfires. We expect that rising air temperature in the current century will cause higher fire frequencies and may encourage waterlogging of forests and ecosystem transformation. [ABSTRACT FROM AUTHOR]

The paper summarizes the evidence of litho-, biostratigraphy and 14C dating of sedimentary sequences studied in natural outcrops and bottom deposits in small lakes, as well as data on coastal morphology in the depressions of Ekostrovskaya and Babinskaya Imandra, the southern sub-basins of Lake Imandra. Lithological, 14C and diatom data suggest that the brackish-water reservoir followed by the fresh-water one existed in the Ekostrovskaya Imandra depression during the Younger Dryas chronozone prior to 11,400cal. yr BP. The Fennoscandian Ice Sheet margin is assumed to have been located in the Lake Imandra basin, covering western Babinskaya Imandra earlier than c. 10,250 cal. yr BP. The early Holocene c. 11,400-8,500 cal. yr BP was marked by a significant westward retreat of the ice margin in the western Lake Imandra depression and adjacent areas, and an extensive fresh-water pra-Imandra Lake basin was formed there. At the end of the Preboreal, earlier than c. 9,210-8,500 cal. yr BP, the pra-Imandra Lake coastline was at least 16-18 m higher than the modern one, as can be assumed according to coastal morphology and lithostratigraphical data. The coastline of that reservoir changed, water square slightly reduced, and isolated small lakes emerged on coasts during the early Holocene. [ABSTRACT FROM AUTHOR]

This paper presents the results of pollen, diatom, charcoal, and sediment analyses from Lake Bol'shoye Zavetnoye, situated between the Gulf of Finland and Lake Ladoga on the Karelian Isthmus, north-western Russia. The main goal is to contribute to the discussion of Neolithic land use in north-eastern Europe. The article aims to answer questions related to Stone Age hunter-gatherer economy, ecology, and anthropogenic environmental impact through a comprehensive combination of multiple types of palaeoecological data and archaeological material. According to diatom data, Lake Bol'shoye Zavetnoye was influenced by the water level oscillations of Ancient Lake Ladoga during much of the Holocene. Intensified human activity and prolonged human occupation become visible in the Lake Bol'shoye Zavetnoye pollen data between 4480 BC and 3250 BC. During the final centuries of the Stone Age, a new phase of land use began, as several anthropogenic indicators, such as Triticum, Cannabis, and Plantago lanceolata appear in the pollen data and a decrease in Pinus values is recorded. In general, the results indicate that socio-cultural transformations could have taken place already from the mid-5th millennium BC onwards, including new ways of utilizing the environment, perhaps also in the field of subsistence, even though the livelihood was based on foraging throughout the period. [ABSTRACT FROM AUTHOR]

The temporal variability of air temperature in the Middle Volga region from 1828 to 2021 is considered according to instrumental observations at the oldest meteorological station in the east of the East European Plain (Kazan University) and throughout the Asian part of Russia against the background of long-term climate fluctuations in the Northern Hemisphere of Earth. A general trend toward an increase in air temperature was revealed. It was found that climate change in Kazan was consistent with the climatic processes that occurred in the Middle Volga region as a whole. The greatest warming for the entire observation period was observed in the winter and spring seasons of the year. In December, warming occurred at a maximum rate of 0.28 °C/10 years. At the same time, the most intense warming process was observed from 1991 to 2021. The analysis of low-frequency fluctuations in the series of monthly average air temperatures made it possible to identify different periods of change, both in type (direction) and intensity. It is shown that in the Middle Volga region, positive anomalies of air temperature have occurred more often than negative ones in recent decades. Statistical data processing was also carried out for 30-year periods, starting from the first period, i.e., 1841–1870. This made it possible to reveal long-term changes in air temperature. Comparisons of climatic parameters in two periods, i.e., 1828–1945 and 1946–2021, allowed us to reliably detect the climatic beginning of the increasingly identifiable Anthropocene epoch (since 1946), characterized by a sharp increase in air temperature, increased interannual variability of the air temperature regime, and a significant increase (by about three times) in the rate of warming in the Middle Volga region. A correlation was made between atmospheric circulation indices and air temperature fluctuations in Kazan over different periods. The closest relationship was found for the 1990–2020 period. It is shown that the contribution of global factors to air temperature variability in the Middle Volga region during the Anthropocene reached 37% in winter and 32% in summer; in annual terms, this contribution amounted to 54%. [ABSTRACT FROM AUTHOR]

The paper reports geochemical parameters of units in a peat bed in a raised bog in the southern Tyumen territory. Based on radiocarbon dates and the variability of the geochemical data, the following four evolutionary stages of the bed in the Holocene are distinguished: an ancient lake (5600-5750 years B.P.), low-land-bog peat (4550-5600 years B.P.), transitional-type peat (4200-4550 years B.P.), raised-bog peat. The major-component technique was applied to analyze relations between various parameters of the bed and evaluate the variations in the condition under which the bog evolved with time, including climatic conditions (in relative units). An anthropogenic signal of the accumulation of certain metals in bog systems is distinguished. [ABSTRACT FROM AUTHOR]

This article presents the generalization results of studying the long-term history of paleofires in the world and on the territory of Russia specifically. Perspective and reliable methods of reconstructing the local and regional dynamics of paleofires – micro- and macro-charcoal analyzes, are considered. In the article, we analyze approaches to the study of paleofires, methods of processing and identifying micro- and macroscopic charcoal particles, including the state-of-the-art software tools for their identification ("The Charcoal Quantification Tool", "WinSEEDLETM") and analysis ("CharAnalysis") based on a review of world and Russian scientific achievements. In addition, the possibilities of modern international paleofire databases (Global Charcoal Database, Reading Palaeofire Database), which contain up-to-date information on local and regional paleofire data in the Holocene, are considered here. The results of the study of paleofires globally and on the territory of Russia in particular are analyzed and possible research directions along with fire reconstruction issues are highlighted. The review of Russian publications has shown that the central and south parts of the East European Plain, as well as the southeast of Western Siberia, are the most studied regions in terms of reconstructing the dynamics of paleofires. Few similar studies were carried out in the Urals Mts., Eastern Siberia and the Far East, but most of the regions of Russia remain understudied in this regard. In recent years, Russian researchers are mainly focused on the study of local fire dynamics based on the use of macro-charcoal analysis. The analysis of international paleofire databases (Global Charcoal Database, Reading Palaeofire Database) shows that these data need to be radically revised in relation to key sites in Russia. The authors present a generalized scheme-map of Russia indicating the key areas where paleofire dynamics were reconstructed using micro- or macro-charcoal analyzes. [ABSTRACT FROM AUTHOR]

Although extensive archeological research works have been conducted in the Serteya region in recent years, the Holocene climate history in the Western Dvina Lakeland in Western Russia is still poorly understood. The Neolithic human occupation of the Serteyka lake–river system responded to climate oscillations, resulting in the development of a pile-dwelling settlement between 5.9 and 4.2 ka cal BP. In this paper, we present the quantitative paleoclimatic reconstructions of the Northgrippian stage (8.2–4.2 ka cal BP) from the Great Serteya Palaeolake Basin. The reconstructions were created based on a multiproxy (Chironomidae, pollen and Cladocera) approach. The mean July air temperature remained at 17–20 °C, which is similar to the present temperature in the Smolensk Upland. The summer temperature revealed only weak oscillations during 5.9 and 4.2 ka cal BP. A more remarkable feature during those events was an increase in continentality, manifested by a lower winter temperature and lower annual precipitation. During the third, intermediate oscillation in 5.0–4.7 ka cal BP, a rise in summer temperature and stronger shifts in continental air masses were recorded. It is still unclear if the above-described climate fluctuations are linked to the North Atlantic Oscillation and can be interpreted as an indication of Bond events because only a few high-resolution paleoclimatic reconstructions from the region have been presented and these reconstructions do not demonstrate explicit oscillations in the period of 5.9 and 4.2 ka cal BP. [ABSTRACT FROM AUTHOR]

The Amur Basin, on the border of Russia and China, has accumulated substantial quantities of peat that have allowed the reconstruction of past vegetation and environments, especially during the Holocene. In this paper, a detailed pollen record from the Basin has been constructed for the last 3800 years and interpreted with the assistance of 40 surface pollen samples taken from vegetation types representative of a broader region. In addition, fossil microcharcoal counts were undertaken to explore variation in fire frequency and the role of fire in peat development and landscape disturbance. The record can be divided into four periods. (1) A period of deciduous broadleaved forest dominated by Betula and Quercus accompanied by thriving sedge-dominated wetlands indicating relatively warm and wet conditions between about 3800 and 2000 cal BP. (2) Coniferous and broad-leaved mixed forest domination between about 2000 and 680 cal BP indicating a shift to a cooler climate. (3) Betula-dominant deciduous forest, reduced sedge-dominated wetlands and increased burning between about 680 and 250 cal BP indicating further drying and cooling during the Little Ice Age. (4) Secondary pine forest combined with a large increase in fire activity as well as a further reduction in the swamp environment signaling substantial human impact in the last 250 years. [ABSTRACT FROM AUTHOR]

The polar bear (Ursus maritimus) is the apex predator of the Arctic but its distribution throughout the Pleistocene and Holocene has not previously been reported. Although natural death specimens of this species ('fossils') are rare, archaeological remains are much more common. This historical compilation presents the record of known ancient polar bear remains from fossil and archaeological contexts before AD 1910. Most remains date within the Holocene and derive from human habitation sites within the modern range of the species, with extralimital specimens documented in the north Atlantic during the late Pleistocene and in the southern Bering Sea during the middle Holocene reflecting natural expansions of sea ice during known cold periods. The single largest polar bear assemblage was recovered from an archaeological site on Zhokhov Island, Russia, occupied ca. 8,250-7,800 a BP during the warmer-than-today Holocene Climatic Optimum: 5,915 polar bear bones were recovered, representing 28% of all remains identified. Polar bear fossils and archaeological remains across the Arctic are most often found in proximity to areas where polynyas (recurring areas of thin ice or open water) are known today and which likely occurred in the past, including for the oldest known fossil from Svalbard (ca. 130-115 k a BP) and the oldest known archaeological specimens from Zhokhov Island (ca. 8,000 a BP). This pattern indicates that as they do today, polar bears may have been most commonly found near polynyas throughout their known historical past because of their need for ice-edge habitats at which to hunt seals. [ABSTRACT FROM AUTHOR]

Studies of 5800 samples of bone and tooth fossils of rodents, lagomorphs, and carnivores collected from loose deposits of Chernyshevskaya-III Cave (52°38′ N, 58°53′ E; Kizil district, Chelyabinsk oblast, Russia) have allowed for the composition and structure of small mammal communities that inhabited the Southern Trans-Urals in the final stage of the Atlantic period (5210 ± 90 years BP, Ki-15500) of the Holocene to be described. The communities included 30 taxa belonging to three orders: Carnivora, Lagomorpha, and Rodentia, with six, two, and 22 species, respectively. The narrow-skulled vole (49%) dominated in the species structure of herbivorous small mammal communities. Codominants were the steppe lemming and the common vole (about 11% each). Steppe (19%) and meadow (18%) groups of species were widespread at that time. Forest and riverside species were also present (about 4% in each group). The existence of the zonal steppe type of small mammal communities with significant participation of mesophilic (mainly meadow) elements is reconstructed for the Southern Trans-Urals for that time. The data obtained reveal humid conditions in the study area during the final stage of the Atlantic phase of the Holocene period. [ABSTRACT FROM AUTHOR]

Abstract: The oxygen isotope composition of diatom silica (δ18Odiatom) from marine and lake sediments is helpful for the interpretation of the past climate and environments, especially when complemented by other proxy records. This paper presents a Holocene oxygen isotope record of diatoms from Lake Kotokel, located 2 km east of Lake Baikal in southern Siberia, Russia. The isotope record displays variations in δ18Odiatom from +23.7 to +30.3‰ from about 11.5 ka BP until today. Comparing the isotope composition of recent Lake Kotokel water (mean δ18O = −12‰) to that of the most recent diatom sample (δ18O = +27.5‰), an isotope fractionation in the right order of magnitude was calculated. The Kotokel δ18O diatom record is controlled by changes in the isotopic composition of the lake water rather than by lake temperature. Lake Kotokel is a dynamic system triggered by differential environmental changes closely linked with various lake-internal hydrological factors. A continuous depletion in δ18O of 6.6‰ is observed from early to late Holocene, which is in line with other hemispheric environmental changes (i.e. a mid- to late Holocene cooling). Enhanced evaporation effects and higher relative supply from a southeasterly moisture source explain the relatively heavy isotopic composition in a rather cold early Holocene. In summary, changes in the Holocene δ18O diatom record of Lake Kotokel reflect variations in δ18O of precipitation linked with both air temperatures (T air) as well as evaporation effects and, to a lesser degree, meltwater pulses from the mountainous hinterland and changing atmospheric moisture sources. [Copyright &y& Elsevier]

Abstract: While substantial progress has been achieved in hunter–gatherer research over the last century, it is still the case that the understanding of the cultural dynamism, variability, and resilience of Holocene hunter–gatherers remains rather impoverished. Emerging archaeological insights suggest that the prehistory of many forager societies included periods of sudden cultural transformation, marked by major shifts in subsistence strategies, settlement patterns and associated social life. Recent theoretical and methodological advances are enabling archaeologists to reconstruct the cultural dynamics of Holocene hunter–gatherers in an unprecedented degree of detail. This is especially true in regions that contain large prehistoric cemeteries, which can provide the base data for bioarchaeological reconstruction of individual life histories, shedding light on forager life-ways, their subsistence strategies and mobility patterns. Renewed attention is also being directed at the role of unstable environments and climate, which would have formed important contextual factors influencing how local cultural dynamics were played out. However, identifying explicit causal links between environmental instability and culture change remains empirically challenging. This paper investigates the major sequences of Holocene hunter–gatherer culture change in two regions of Northeast Asia and details how the new Baikal–Hokkaido Archaeology Project will be researching the causal factors driving these cultural processes, including the possible role of climate and environment. [Copyright &y& Elsevier]

In this paper all the Stone Age and Early Metal Period (ca. 8600 cal BC - 300 AD) radiocarbon dates from the Karelian Isthmus, Russia, are compiled and their archaeological usability assessed using a set of evaluation principles. The quality of radiometric dates from such a large area has rarely been methodologically examined in Finnish or North-West Russian archaeology, and is applied here for the first time on the present material. Special attention is given to the discussion on the deficiencies and limitations of the current data. Based on the 81 dates evaluated as useful, a tentative radiocarbon chronology is presented for the study area. This is generally in sequence with the chronologies of the nearby areas, but suggests some differences especially towards the end of Stone Age, as well as the presence of biases caused by taphonomic and research-related factors. [ABSTRACT FROM AUTHOR]

Abstract: The paper presents the first paleontological data (pollen, plant macrofossil, diatom and ostracod) on the sediments of Lake Beloye, which is situated in the forest-steppe zone of Western Siberia. Our study contributes to better understanding of the Middle–Late Holocene regional to local environmental changes. Regionally, we recognized a cold stage of 3.4–2.3 calibrated ka BP and a dry stage of 2.8–1.7ka BP. The dry stage coincides with the climate-driven lowered level of the lake at 2.6–1.5ka BP. Later, the climate changed to warmer and wetter, which resulted in a highest stand of the lake at 1.3–0.2ka BP and was followed by the lowering of the lake. Forest-steppe persisted in this area during the whole period under consideration, but probably shifted southward. Such a shift is reflected in the environment around Lake Beloye similar to that of modern taiga, which existed at 3.2–1.3ka BP, however, compared to the colder and wetter climate of taiga, the conditions were colder and drier. The local plant associations and the lake ecosystem were affected by those events of climate and lake level changes. The initial eutrophic sedge-reed swamp evolved to the oligo-mesotrophic sphagnum bog, which existed around the lake at 3.2–1.3ka BP. Later, the bogging process was interrupted by the lake transgression, after which the dried bog around the lake was occupied by the birch forest. The lake ecosystem was strongly affected by the 3.4ka BP climate change: the low-alkaline eutrophic lake with abundant water higher plants and diatoms changed to the alkaline oligotrophic lake with calcium-fixing macrophytic algae and angiosperms. This resulted in total change of lake''s bio-geochemical and sedimentation patterns. [Copyright &y& Elsevier]

This study presents the first centennial‐scale multi‐proxy record from the East Sayan Mountains, which are part of the central Asian 'water tower' massif. The record from Lake Kaskadnoe in the Jom‐Bolok area shows changes in vegetation and climate since c. 14.2 cal. ka BP. Although the study site is in an area with active volcanism, there is no clear evidence that volcanic eruptions influenced the local vegetation. At c. 14.2–12.9 cal. ka BP, regional climate was sufficiently warm and moist to allow scattered growth of Picea, Larix and Betula nana around the lake. A cooling episode at c. 12.9–11.5 cal. ka BP is coincident with the Younger Dryas and led to the predominance of shrub tundra in the basin. Cool and moist conditions c. 11.5–9.0 cal. ka BP resulted in the spread of Pinus sibirica in the catchment of Lake Kaskadnoe. The Middle Holocene, c. 9.0–4.5 cal. ka BP, featured a warmer and drier regional climate, which led to a decrease in high‐elevation dark conifer forest. Subsequently, the onset of the Neoglacial and a cooler climate is indicated by the spread of Larix sibirica and Pinus sibirica in the study area. Lateglacial and Holocene moisture conditions in the East Sayan Mountains have primarily been controlled by the interaction of the westerlies and the East Asian Summer Monsoon and show a drying trend through time; long‐term insolation changes affected both the Monsoon and regional temperatures. The pattern of moisture decrease in the latter part of the Holocene is seen at sites in adjacent regions of the central Asian mountains. [ABSTRACT FROM AUTHOR]

Bolshaya Imandra, the northern sub‐basin of Lake Imandra, was investigated by a hydro‐acoustic survey followed by sediment coring down to the acoustic basement. The sediment record was analysed by a combined physical, biogeochemical, sedimentological, granulometrical and micropalaeontological approach to reconstruct the regional climatic and environmental history. Chronological control was obtained by 14C dating, 137Cs, and Hg markers as well as pollen stratigraphy and revealed that the sediment succession offers the first continuous record spanning the Lateglacial and Holocene for this lake. Following the deglaciation prior to c. 13 200 cal. a BP, the lake's sub‐basin initially was occupied by a glacifluvial river system, before a proglacial lake with glaciolacustrine sedimentation established. Rather mild climate, a sparse vegetation cover and successive retreat of the Scandinavian Ice Sheet (SIS) from the lake catchment characterized the Bølling/Allerød interstadial, lasting until 12 710 cal. a BP. During the subsequent Younger Dryas chronozone, until 11 550 cal. a BP, climate cooling led to a decrease in vegetation cover and a re‐advance of the SIS. The SIS disappeared from the catchment at the Holocene transition, but small glaciers persisted in the mountains at the eastern lake shore. During the Early Holocene, until 8400 cal. a BP, sedimentation changed from glaciolacustrine to lacustrine and rising temperatures caused the spread of thermophilous vegetation. The Middle Holocene, until 3700 cal. a BP, comprises the regional Holocene Thermal Maximum (8000–4600 cal. a BP) with relatively stable temperatures, denser vegetation cover and absence of mountain glaciers. Reoccurrence of mountain glaciers during the Late Holocene, until 30 cal. a BP, presumably results from a slight cooling and increased humidity. Since c. 30 cal. a BP Lake Imandra has been strongly influenced by human impact, originating in industrial and mining activities. Our results are in overall agreement with vegetation and climate reconstructions in the Kola region. [ABSTRACT FROM AUTHOR]

• Mineral composition of the bottom part of the peat deposit was studied. • This part of deposit is characterized by a change in the environmental conditions. • Clay minerals of peat layers have been inherited from the underlying loam layer. • Geochemistry of peat layer is different from the organo-mineral sediments and loam. • Authigenic sulfides have formed in the reducing conditions of the basal peat. This paper is devoted to a study of the nature and origin of the mineral matter in the Vasyugan Mire in Western Siberia. Based on mineralogical and geochemical analyses, new results were obtained concerning the mineral composition within the bottom part of the peat deposit for different landscape zones in the Vasyugan Mire. This part of the peat deposit represents a transition sequence from peat through organo-mineral sediments (OMS) to basal loams and is characterized by a gradient change in the physicochemical and environmental conditions with depth. In the same sequence, pH and peat ash yield increase, while moisture decreases. The clay minerals identified in the basal layers of the mire, consisting of loam, OMS and peat, include illite, chlorite, kaolinite and smectite. All these clay minerals found in the OMS and peat layers are believed to have been inherited with little change from the underlying loam layer during the initial transient stage of mire development. That this is indeed the case is strongly suggested by the extraordinary correspondence in the mean content of over 40 trace elements between the OMS and loam layers. In the overlying peat layer, however, some elements, including U, W, Sb, Sn, Mo, Zn, Cd, Nb, Ta, Br and B, are present in higher concentrations than in the OMS and loam. Scanning electron microscope observations suggest that this can be at least partly accounted for by the precipitation of sulfide phases in the strongly reducing and acidic environment of the peat, although whether by inorganic or microbial processes is unknown. The age of the Vasyugan Mire within the Holocene succession is discussed and it is concluded that it developed either during the Atlantic Period (8 ka–6 ka BP) or during the upper part of the Sub-Boreal Period (4 ka BP). [ABSTRACT FROM AUTHOR]

Data on the historical change of the Transbaikalian malacofauna in the Neopleistocene and Holocene is presented. Aquatic mollusc shells from archaeological excavations of the ancient settlements dating from the Neolithic period to Medieval and also from a drill hole of the Neopleistocene alluvial deposits were collected. In total eight species of bivalve molluscs from the families Margaritiferidae, Unionidae, Lymnocardiidae, Glycymerididae [marine], and two gastropod species from families Viviparidae and Planorbidae were identified. These species were aged using radiocarbon dating. It was found that the species ranged in age from more than 50.000 to 2.080–1.210 years BP. Five species inhabited the Transbaikal region which are locally extirpated today. Their disjunctive ranges in the past included southern Europe and Western and Eastern Siberia to Transbaikalia and in the east to Far East and Primorye Territory of Russia. A remarkable finding is that of the bivalve genus Monodacna, which was found very far from its native range, the Ponto-Caspian region. The time of existence and extirpation of the thermophilic species of genera Monodacna, Planorbis, Lanceolaria and Amuropaludina corresponds to cycles of the warming and cooling in Pleistocene and Holocene according to regional climate chronological scales. These species can be used as palaeoclimate indicators. Change of the regional malacofaunal species composition is connected with the natural climatochron cycles in the Pleistocene and Holocene resulting in evidence for succession. In the course of this succession, these stenothermal species became extirpated on a regional level, decreasing their global ranges. [ABSTRACT FROM AUTHOR]

The Kamyshovoye Lake sedimentary record in the southeastern Baltic Sea region was studied to reconstruct climatic fluctuations and the abiotic responses to them during the Lateglacial and Early Holocene. New results from chironomid, isotopic, palaeomagnetic and geochemical data analyses were correlated with earlier evidence of lithological and palynological changes in the Kamyshovoye Lake record. The section of the record that was studied covered the interval between 15 200 and 6500 cal. a BP. Palaeoclimatic reconstructions showed that during the Younger Dryas there was a two‐step decrease in the mean July temperature. The temperature dropped by 3 °C in the period from ̃12 650 to 12 300 cal. a BP, and then it dropped by another 0.5 °C to a minimum of 11.5 °C at 11 900 cal. a BP. During the Younger Dryas–Holocene transition, a temperature increase of 3 °C can be seen over a period of several centuries, inferred from the chironomid data. Further, the temperature curve showed that significant fluctuations continued until ̃9500 cal. a BP. During the coolings, the average July temperature dropped to values that were typical for the Younger Dryas, while values characteristic for the Allerød were only reached at around 9700 cal. a BP. After 9500 cal. a BP, a more stable, gradual increase in temperature was recorded. The short‐term Early Holocene climatic oscillations are clearly traced in the Kamyshovoye sequence, although the responses of the natural components are sometimes asynchronous. In the case of the Kamyshovoye study, the geochemical data seem to be a sensitive indicator of the climatic and environmental changes despite the absence of an evident response to the Holocene onset at ̃11 700 cal. a BP. Considerable changes in the geochemical pattern are recorded later, at ̃11 500 cal. a BP, coinciding with noticeable changes in the development of vegetation. The results obtained in this study contribute to a deeper understanding of how global climatic trends are manifested on a local scale. [ABSTRACT FROM AUTHOR]

The White Sea being connected with the Arctic Ocean via the Barents Sea has an influence on its water temperature/salinity structures and biological processes and thus has an indirect impact on the Eurasian climate system. In this work, we have managed to find a correspondence between the climate fluctuation in the Holocene and changes in the geochemical and microfossil properties in the sediment core of the White Sea. For the first time, the element speciation in the sediment core covering about 10,000 cal yr BP period was investigated. The cooling periods (the early Holocene and the Subboreal stage) were characterized by a trend of increase in Si, Al, and Ti contents and Ti/Al ratios, which reflect lithogenous contribution, and decrease in geochemically labile forms of trace elements. A significant increase in the content of organic-bound trace elements and biogenic components (Сorg, BSi, and chlorin) was observed during periods of Holocene climatic optimums. The evident relationship between the metal speciation and indicators of the sedimentation paleoenvironment is observed at the stage of the active phase of early diagenesis after the slowing down of the biogeochemical processes. Down-core decrease in the Mn oxyhydroxide content exhibited a weakening of diagenesis processes at the ~130–150 cm depth. [ABSTRACT FROM AUTHOR]

Fossil pollen, conifer stomata, and charcoal records for the last 10,000 years were studied from three small hollow sites (Larix Hollow, Mosquito Hollow, and Olga Hollow) located at the modern western range limit of Siberian larch (Larix sibirica) in northwestern Russia to investigate the role of forest fires in stand-scale dynamics of taiga vegetation. Wavelet coherence analysis was utilized to reveal the significance of fire on the vegetation composition at different timescales by assessing the phase and strength of the relationship between forest fires and most common boreal tree taxa in a time–frequency window. Pollen and stomata data show that all of the modern-day common tree taxa, including Norway spruce (Picea abies) and Siberian larch, have been present in the study region since the early Holocene. The absence of charcoal layers at Mosquito Hollow suggests that this site has acted as a fire-free refugium with continuous dominance of spruce throughout the Holocene. Meanwhile, the Larix Hollow record indicates frequent local fire events and as a consequence, a more variable tree species composition. The wavelet coherence results show that the impact of forest fires on vegetation varies from short-term (<200-year periods) changes in individual tree taxa to long-term (400–800 years) changes in forest composition, such as the expansion of spruce population after local high-intensity fires around 7500–7000 cal. yr BP and the increase in abundance of birch and alder during periods of high fire frequency. Our results suggest that Holocene fire histories can be markedly different within a small geographical area, demonstrating the importance of site-specific factors in the local fire regime in the unmanaged taiga forest. [ABSTRACT FROM PUBLISHER]

Thermokarst lakes formed across vast regions of Siberia and Alaska during the last deglaciation and are thought to be a net source of atmospheric methane and carbon dioxide during the Holocene epoch. However, the same thermokarst lakes can also sequester carbon, and it remains uncertain whether carbon uptake by thermokarst lakes can offset their greenhouse gas emissions. Here we use field observations of Siberian permafrost exposures, radiocarbon dating and spatial analyses to quantify Holocene carbon stocks and fluxes in lake sediments overlying thawed Pleistocene-aged permafrost. We find that carbon accumulation in deep thermokarst-lake sediments since the last deglaciation is about 1.6 times larger than the mass of Pleistocene-aged permafrost carbon released as greenhouse gases when the lakes first formed. Although methane and carbon dioxide emissions following thaw lead to immediate radiative warming, carbon uptake in peat-rich sediments occurs over millennial timescales. We assess thermokarst-lake carbon feedbacks to climate with an atmospheric perturbation model and find that thermokarst basins switched from a net radiative warming to a net cooling climate effect about 5,000 years ago. High rates of Holocene carbon accumulation in 20 lake sediments (47 ± 10 grams of carbon per square metre per year; mean ± standard error) were driven by thermokarst erosion and deposition of terrestrial organic matter, by nutrient release from thawing permafrost that stimulated lake productivity and by slow decomposition in cold, anoxic lake bottoms. When lakes eventually drained, permafrost formation rapidly sequestered sediment carbon. Our estimate of about 160 petagrams of Holocene organic carbon in deep lake basins of Siberia and Alaska increases the circumpolar peat carbon pool estimate for permafrost regions by over 50 per cent (ref. 6). The carbon in perennially frozen drained lake sediments may become vulnerable to mineralization as permafrost disappears, potentially negating the climate stabilization provided by thermokarst lakes during the late Holocene. [ABSTRACT FROM AUTHOR]

Alluvial, aeolian and pedogenic horizons were detected in floodplain deposits of small rivers of Southeastern Transbaikalia. The occurrence of pedogenic horizons in floodplain deposits indicates that they were formed at periods of an enhancement in erosion activity at the end of the dry cold phase and at the beginning of the dry warm phase during the overall course of heat availability and humidification of climate in the latter half of the Holocene. An enhancement in fluvial activity corresponded to the cold humid phase, whereas an intensification of the aeolian process was taking place during the dry cold phase. [ABSTRACT FROM AUTHOR]

We examine the vegetation cover of Sidorov and Gerasimov Islands in comparison with the continental shore of Tabunnaya Bay. It is found that Sidorov, Gerasimov and Bychii Islands differ from the shore area of Tabunnaya Bay in higher species diversity of lichens. Burozems of the continental hummocky terrain are characterized by an eroded shallow and strongly skeletal profile. Sidorov and Gerasimov Islands, unlike the continental shore area, distinctly show an additional phase of development of mixed (coniferous-broad-leaved) forest preceding the contemporary period; furthermore, Artemisa gmelinii associations and lime formations were of widespread occurrence in this area during cold climatic periods, while the continental shore area was the home for birch-shrub communities. [ABSTRACT FROM AUTHOR]

The article discusses the age of extrusive rocks found in Kamchatka Peninsula, Russia, and highlights the application of laser ablationin dating of young zircons. It informs that the application of tephra chronology and radiocarbon dating resulted in the study of the chronology of volcanism in the Holocene period. It also informs that pan sampling for zircons and their geochronologic studying can be used in solving various problems.

The results of studies on small mammal bone assemblages from seven cave-type sites on the Shchugor and Kozhim rivers are presented. Four stages in the development of small mammal fauna in the Nether-Polar Urals are described, which correspond to the Alleröd, Younger Dryas, Early Holocene, and Subatlantic periods. The moderately cryohydrophilic fauna of the Alleröd was replaced by an atypically 'mild' xerophylic community in the Younger Dryas. In the Early Holocene, its structure still included considerable proportions of tundra species, which, along with forest species, were also found in the subfossil assemblage from the Subatlantic. It is shown that the transformation of the small mammal fauna in the above sites had a specific pattern, compared to that in other regions of northeastern Europe and to the dynamics of the natural environment and climate. [ABSTRACT FROM AUTHOR]

Fossil ostracod assemblages were investigated in five AMS 14 C-dated cores from various water depths of the Laptev and Kara seas ranging from the upper continental slope (270 m) to the present-day shelf depth (40 m). Six fossil assemblages were distinguished. These represent the varying environmental conditions at the North Siberian continental margin since about 18 ka. In the cores from the shelf the ostracod assemblages reflect the gradual transition from an estuarine brackish-water environment to modern marine conditions since 12.3 ka, as induced by the regional early Holocene transgression. The core from the upper continental slope dates back to c. 17.6 ka and contains assemblages that are absent in the shelf cores. The assemblage older than 10 ka stands out as a specific community dominated by relatively deep-water Arctic and North Atlantic species that also contains euryhaline species. Such an assemblage provides evidence for past inflows of Atlantic-derived waters from as early as c. 17.2 ka, probably facilitated by upwelling in coastal polynyas, and a considerable riverine freshwater influence with enhanced surface water stratification owing to the proximity of the palaeocoastline until early Holocene times. In all studied cores, relative increases in euryhaline species dominant in the inner-shelf regions are recorded in the mid-late Holocene sediments (<7 ka), which otherwise already contain modern-like ostracod assemblages with relatively deep-water species. This observation suggests euryhaline species to be largely sea-ice- and/or iceberg-rafted and therefore may provide evidence for a climate cooling trend. [ABSTRACT FROM AUTHOR]

Eastern Siberia's Lake Baikal and its tributaries are productive fisheries, and the region's Holocene archaeological sites confirm that this is a long-standing phenomenon. Recent zooarchaeological investigations of sites here allow Holocene fishing practices to be examined in more detail than was previously possible. Along much of the lake's coast, bathymetry is very steep and the water very cold; here fishing appears to have been supplemental to other subsistence practices such as sealing and ungulate hunting. In shallower areas, waters were warmer and supported very productive fisheries for littoral species, perhaps through the use of nets or traps. The region's rivers offered their own resident species but also were used as spawning grounds by some lake fishes. The lake's littoral fisheries, while productive, likely produced fish throughout the year and did not require complex labor organization to be effectively used. Some sections of the region's rivers, particularly those that were spawning grounds for some lake fishes, may have required more complex sociopolitical organization to be exploited efficiently. Such fish runs were short-lived and the best fishing places likely were spatially restricted. This potentially created the need for pools of labor, required organization of harvesting and processing, and generated surpluses that could be stored and manipulated. [ABSTRACT FROM AUTHOR]

Peatlands are remarkable for their specific biodiversity, crucial role in carbon cycling and climate change. Their deposits preserve organism remains that can be used to reconstruct long-term ecosystem and environmental changes as well as human impact in the prehistorical and historical past. This study presents a new multi-proxy reconstruction of the peatland and vegetation development investigating climate dynamics and human impact at the border between mixed and boreal forests in the Valdai Uplands (the East European Plain, Russia) during most of the Holocene. We performed plant macrofossil, pollen, testate amoeba, Cladocera, diatom, peat humification, loss on ignition, carbon and nitrogen content, δ13C and δ15N analyses supported by radiocarbon dating of the peat deposits from the Krivetskiy Mokh mire. The results of the study indicate that the wetland ecosystem underwent a classic hydroserial succession from a lake (8300 BC–900 BC) terrestrialized through a fen (900 BC–630 AD) to an ombrotrophic bog (630 AD–until present) and responded to climate changes documented over the Holocene. Each stage was associated with clear changes in local diversity of organisms responding mostly to autogenic successional changes during the lake stage and to allogenic factors at the fen-bog stage. The latter can be related to increased human impact and greater sensitivity of peatland ecosystems to external, especially climatic, drivers as compared to lakes. [ABSTRACT FROM AUTHOR]