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During the last deglaciation (18–8 kyr BP), shelf flooding and warming presumably led to a large-scale decomposition of permafrost soils in the mid-to-high latitudes of the Northern Hemisphere. Microbial degradation of old organic matter released from the decomposing permafrost potentially contributed to the deglacial rise in atmospheric CO2 and also to the declining atmospheric radiocarbon contents (Δ14C). The significance of permafrost for the atmospheric carbon pool is not well understood as the timing of the carbon activation is poorly constrained by proxy data. Here, we trace the mobilization of organic matter from permafrost in the Pacific sector of Beringia over the last 22 kyr using mass-accumulation rates and radiocarbon signatures of terrigenous biomarkers in four sediment cores from the Bering Sea and the Northwest Pacific. We find that pronounced reworking and thus the vulnerability of old organic carbon to remineralization commenced during the early deglaciation (∼16.8 kyr BP) when meltwater runoff in the Yukon River intensified riverbank erosion of permafrost soils and fluvial discharge. Regional deglaciation in Alaska additionally mobilized significant fractions of fossil, petrogenic organic matter at this time. Permafrost decomposition across Beringia’s Pacific sector occurred in two major pulses that match the Bølling-Allerød and Preboreal warm spells and rapidly initiated within centuries. The carbon mobilization likely resulted from massive shelf flooding during meltwater pulses 1A (∼14.6 kyr BP) and 1B (∼11.5 kyr BP) followed by permafrost thaw in the hinterland. Our findings emphasize that coastal erosion was a major control to rapidly mobilize permafrost carbon along Beringia’s Pacific coast at ∼14.6 and ∼11.5 kyr BP implying that shelf flooding in Beringia may partly explain the centennial-scale rises in atmospheric CO2 at these times. Around 16.5 kyr BP, the mobilization of old terrigenous organic matter caused by meltwater-floods may have additionally contributed to increasing CO2 levels.

The article presents results of analysises the loss on ignition and radiocarbon dating of the bottom sediments of Lake Terebenskoye. Based on the obtained data, a preliminary reconstruction of the sedimentation processes of lakes of the Valdai Upland in the Holocene is constructed. The stages of minerogenic sedimentation in the Older and Younger Dryas and organogenic sedimentation in the Allerd and Preboreal are distinguished.

Sedimentary δ15 N records in two IMAGES cores (MD012404 and MD012403) retrieved from the Okinawa Trough (OT) in the western North Pacific reveal deglacial increases with two peaks occurring during the Bølling/Allerød and the Preboreal/early Holocene periods. These peaks are synchronous with previously reported δ15 N peaks in the Eastern Tropical North Pacific, although the amplitudes (from 3.8 to 5.8‰) are much smaller in the OT. Similar δ15 N values for the last glacial maximum and the late-Holocene observed by us at a site far from the present-day zones of water-column denitrification (WCD) indicate that the mean 15 N/14 N of nitrate in the upper ocean did not differ much between the two climate states. The accumulation rate of organic carbon and total sulfur content are used as indices of the local WCD potential. The results suggest that enhancement of global WCD rather than local denitrification should be responsible for the deglacial maxima of sedimentary δ15 N in the Okinawa Trough. Our data could provide additional constraints to better understand changes in nitrogen budget during the glacial to interglacial transition.

Skipsea Withow is well known for producing a barbed point and faunal remains, thought to date to the Early Mesolithic period, over a century ago. More recently bones were recovered from the eroding cliff face and have been analysed. Although it was considered that they might be elk (Alces alces) due to their large size, it was demonstrated that they are red deer (Cervus elaphus). Further examination suggested that they represent two individuals of slightly different ages. They have been dated to the Early Mesolithic period and the dates overlap with those obtained from the well-known site of Star Carr, located further north in the Vale of Pickering. It is considered unlikely that the red deer bones from Skipsea Withow represent two natural deaths on the edge of the mere, and it is possible that they are the remains of humanly deposited bones; a practice seen at Star Carr.

We report the first findings of coexisting early Holocene Hasseldalen and Askja-S cryptotephras in a varved sediment record in Lake Czechowskie (Poland). A time span of 152 +11/−8 varve years between the two tephras has been revealed by differential dating through varve counting. This is in agreement within the uncertainties with calculations from radiocarbon-based age models from the non-varved Hasseldala port record in southern Sweden, but shorter than assumed from the non-varved lake record on the Faroe Islands. We discuss possible reasons for the observed differences in duration between the two tephras and provide a revised absolute age for the Askja-S tephra of 11 228 ± 226 cal a BP based on anchoring our floating varve chronology to the absolute timescale by using the Hasseldalen Tephra as dated in the Hasseldala port sediments (11 380 ± 216 cal a BP). This age agrees with radiocarbon age models with larger uncertainty ranges, but is slightly older than radiocarbon-based age models with narrow uncertainty bands and is even 200–300 years older than the age reported from the Faroe Islands record. In addition to these chronological issues we discuss the possible response of the Czechowskie sediment record to the Preboreal climate oscillation.

This paper presents reconstructions of ice sheet boundaries, lacustrine and marine paleobasins, as well as the connections of the Barents and Baltic seas with the North Atlantic from the Last Glacial Maximum to the Holocene. The reconstructions are based on original and published data obtained from the northern and western parts of the Barents Sea and Baltic depressions with account for the available regional schematic maps of deglaciation. The early deglaciation of the Scandinavian–Barents ice sheet culminated with the Bolling-Allerod interstadial (14.5–12.9 cal ka BP), which was characterized by a more vigorous Atlantic meridional overturning circulation (AMOC) and a corresponding increase in surface Atlantic water inflow into the Barents Sea through deep troughs. The Baltic Ice Lake (BIL) remained a dammed-up isolated basin during deglaciation from 16.0 to 11.7 cal ka BP. In the Younger Dryas (YD), the lake drained into the North Sea and was replaced by a brackish Yoldia Sea (YS) at the beginning of the Holocene (Preboreal, 11.7–10.7 cal ka BP), due to a limited connection between two basins through the Narke Strait. In the Barents Sea, the next increase in the Atlantic water influx into the deep basins corresponded to terminal YD and Preboreal events with a culmination in the Early Holocene. The Yoldia Sea became a lake again during the next stage, the Ancylus (~10.7–8.8 cal ka BP). Atlantic water inflow both into the Barents and Baltic seas varied during the Holocene, with a maximum contribution in the Early Holocene, when the Littorina Sea (LS, 8–4 cal ka BP) connection with the North Sea via the Danish Straits was formed to replace the Ancylus Lake. The recent, post-Littorina stage (PS, the last 4 cal ka) of the Baltic Sea evolution began in the Late Holocene.

Découverte en 1990, la grotte-abri de Peyrazet (Creysse, Lot, France) se situe dans le Haut-Quercy en bordure du causse de Martel, à quelques centaines de mètres du cours actuel de la Dordogne. Les fouilles menées depuis 2008 livrent une archéoséquence du Tardiglaciaire qui permet de combler certaines lacunes documentaires régionales et plus largement du Sud-Ouest de la France. Au Magdalénien supérieur succède un niveau ayant donné des indices d’un Azilien sensu lato stratigraphiquement séparé du Laborien, ensemble supérieur qui fait l’objet de cet article. Jusqu’alors ce technocomplexe de la fin du Pléistocène et des débuts de l’Holocène demeurait mal connu dans la région. En effet, seuls des travaux anciens menés dans deux gisements permettaient de noter sa présence en Quercy. La découverte d’un ensemble laborien récent (ou Épilaborien) à Peyrazet est l’occasion de conduire une étude collective des divers vestiges dans un cadre archéostratigraphique mieux maîtrisé. L’analyse géoarchéologique met en évidence l’action conjointe du ruissellement et de l’éboulisation comme principaux responsables de la mise en place des dépôts. Dans la partie S-O du site, un lithofaciès de remaniement indique une bioturbation importante en lien avec le creusement de terriers. Bien que leur origine ne soit pas liée aux activités humaines, les rongeurs, les oiseaux, les poissons et les mésomammifères (excepté le lièvre) apportent des données concernant l’environnement des chasseurs-cueilleurs. La grande faune est dominée par le cerf dont les carcasses pourraient avoir été introduites incomplètes sur le site puis traitées pour en extraire la viande et la moelle. Nous avons bénéficié d’une analyse fonctionnelle croisée à l’étude typo-technologique des vestiges lithiques composés pour l’essentiel de silex locaux et régionaux. Ce double regard a permis de mettre en évidence une diversité d’activités mise en œuvre dans la cavité. Une pièce d’ocre rouge, quelques vestiges d’industrie osseuse et des éléments de parure participent également à la description d’une large gamme de tâches effectuées lors d’un séjour prolongé ou de plusieurs occupations successives. La comparaison des pointes de chasse microlithiques avec d’autres gisements sur une vaste échelle géographique conduit à discuter l’attribution de cet ensemble supérieur à différentes phases du Laborien. L’hypothèse d’un Laborien récent (ou Épilaborien) conduit à réfléchir à une perduration de morphotypes ancestraux parallèlement à de nouveaux types d’armatures, observation déjà réalisée notamment à La Borie del Rey dans le Haut-Agenais mais qui demande encore des précisions et de nouvelles découvertes. Discovered in 1990, Peyrazet cave-rock shelter (Creysse, Lot) lies in the Haut-Quercy region at the limits of the Martel limestone plateau, several hundred meters from the current Dordogne River valley. Excavations begun in 2008 produced a Late Glacial archaeo-sequence that sheds new light on several still poorly understood aspects of the archeological record in both the Haut-Quercy region and southwestern France in general. The level overlying the Late Magdalenian occupation produced limited evidence for the Azilian and is stratigraphically separated from the Laborian. This latter techno-complex, dated to the end of the Pleistocene and early Holocene, remains poorly documented in the region, having only been previously identified from two sites in the Quercy. The discovery of a recent Laborian (Epilaborian) occupation at Peyrazet presented the ideal occasion for a collaborative study of the diverse archaeological material recovered from this well-understood archaeo-stratigraphic context. A geoarchaeological analysis produced evidence for both surface runoff and the accumulation of coarse deposits (éboulis) as the principal site formation processes. In the southwest area of the site, a reworked lithofacies demonstrates substantial bioturbation in connection with animal burrowing. Although the presence of rodent, bird, fish, and medium-sized mammals (except hare) cannot be definitively connected to human activity, they nevertheless provide important information concerning the environments exploited by hunter-gatherer groups. Larger species are dominated by red deer whose carcasses were partially processed before being introduced to the site, where meat was subsequently removed and marrow consumed. A functional analysis combined with a typo-technological study of the primarily locally- and regionally-procured lithic material revealed evidence for diverse activities having taken place on-site. An ochre fragment, several bone tools and ornaments equally indicate a large variety of tasks to have been carried out during a single, long occupation or several successive visits. A typo-technological comparison of hunting weaponry (microliths) from sites across a substantial area suggests the assemblage to represent either a Laborian/Epilaborian mix or a unique Epilaborian occupation. This latter case would indicate the persistence of older morphotypes alongside the development of new tools forms, a situation already identified at Borie del Rey in the Haut-Agenais but which requires more detailed study supported by new discoveries.

The fluvial landforms of the last cold stage are represented in the Sub-Carpathian Basins by a system of 2–3 terraces, which grade into alluvial fans of a height of 15–20, 8–12 and 6–8 m above the present riverbeds in the mountain foreland. In the Vistula River valley the 15–20 m high terrace, covered with loess, extends along the western margin of the Sandomierz Basin and northern margin of the Carpathians. Away from the mountain margin, it passes into the sandy terrace plain with dunes. It is formed of at least two Interpleniglacial alluvial fills: the older one dated at 48–36 ka BP (over 50–40.6 ka cal BP) and the younger one dated 30–25 ka BP (34.1–29.0 ka cal BP) thus pertaining to the Upper Pleniglacial. This latter forms a terrace 15 m high. In general, accumulation of fluvial sediments interrupted with erosion phases dominated in the mountain foreland during the period 60–25 ka BP (over 60–29 ka cal BP). The most significant erosion phase took place before the maximum extension of the Vistulian (Weichselian, Wisconsinian) ice sheet (i.e. before 25–20 ka BP = 29–24 ka cal BP) and was connected with a change from an oceanic to a more continental climate. The next alluvial fill of terrace 8–12 m high (with remnants of braided river channels) was formed at the end of the Upper Plenivistulian. The incision of the river channels below the present channel level was followed by aggradation in the Late Vistulian (15–13 ka BP = 18.2–15.6 ka cal BP) accompanied by a change in river channel system from braided to meandering. In the Wisloka and San River valleys alluvial plains extending by lateral erosion of large meanders were abandoned by rivers mainly in the Younger Dryas and the Preboreal. The Late Vistulian large palaeomeanders are missing along lower Sola and lower Dunajec. These rivers, fed from higher mountains, had still tendency to braiding. The climate cooling of the Younger Dryas brought an increase in the delivery of bedload to the river channels and a tendency to braiding in Vistula valley (Drwinka depression). The expansion of forest in the Early Holocene reduced the water discharge and the size of meanders. As a result, their width fallen by 3–5 times. Alluvial data showed also a distinct humid climatic phase ca. 9.5–8.5 ka cal BP.

“Romoty” is the name of a sediment profile from the overgrown lake located in Elk Lakeland (NE Poland). The sediment core, which is 8.4 m in length, documents the development of the reservoir since the melting of dead ice and formation of the lake basin, i.e., before 13,000 years BP, until it became overgrown with plants. The characteristics of the sediments changed from mineral deposits on the bottom (silty sands) to biogenic deposits consisting of dark olive calcareous detritus gyttja and light calcareous gyttja with increasing carbonate content and to peat in the upper part. Based on the data (chemical, stable isotopes, subfossil Cladocera remains, pollen), we have distinguished three main stages of the evolution of Romoty paleolake. The first stage includes the formation of the lake basin in the Late Glacial and early Holocene (Preboreal). The second stage is characterized by the harmonic, natural development of the Romoty paleolake from the Boreal to Subboreal. This stage coincides with a period of climatic warming, and biogenic sediments accumulated in this reservoir at that time. The third stage concerns the disappearance of the lake in the late Holocene (Subatlantic). The lake conditions declined, and the reservoir completely filled with sediments and has transformed into a mire. The characterization of each stage involves a description of environmental conditions occurring in the Romoty paleolake, particularly the Cladocera community, the chemical composition, the temperature and trophy of the water, the water level, the nature of bottom sediments, and the plants occurring in the reservoir and its surroundings. The lowest water temperature occurred in the Late Glacial and Preboreal periods. Since the Boreal period, gradual warming is observed and is expressed through a positive trend in both δ 18 O and δ 13 C and changes in both Cladocera and plant compositions. The lake was deepest at the beginning of the Holocene as a result of dead ice melting (supply of melt water; lowering of the lake bottom) and/or increased precipitation (change in atmospheric circulation). The water level fell during the Atlantic period. Additionally, the cladoceran and non-pollen palynomorph data indicate low trophy followed by an increase in the mesotrophic state. Human impact was documented only by a low occurrence of pollen grains of Cerealia in the youngest sediments (Subatlantic period), suggesting a low penetration by human groups of the area near the Romoty paleolake.

The article presents the results of a combination of isotopic (δ 15 N and δ 13 C), geochemical (TOC, TN, C/N) and palaeobotanical investigations. They were carried out on organic matter (OM) that had been deposited from the Younger Dryas to the Subboreal chronozone in palaolake sediments (north-eastern Poland). OM from the late Younger Dryas consists only a small amount of TOC and TN, which together with the lack of aquatic macrophyte macrofossils confirm low primary production in the then reservoir. The higher values of C/N ratio (18–27) and δ 13 C (ca. −26‰) suggest that OM was mainly terrestrial in origin. During the Preboreal chronozone (11,450–10,150 cal. BP), there was a probable deepening of the reservoir through the melting of dead ice. This might have been intensified by an increase in precipitation and a fall in evapotranspiration during the ‘Preboreal oscillation’. From the early Preboreal chronozone (ca. 11,345 cal. BP), a mixed source of OM is indicated by C/N ratio (from 8 to 13). At the same time significant increase in TOC and TN probably registered a rise in primary production in the palaeolake. From the older part of the Boreal chronozone (ca. 9865 cal. BP) algae productivity increased (the C/N ratio dropped to ca. 8 and was then constant). At the beginning of the Atlantic chronozone (ca. 8650 cal. BP) a probable increase in the water level caused the partial relocation of OM from the reed swamp belt and/or the adjacent alder carr into deeper sections of the palaeolake (an increase in TOC and TN). In the late Atlantic chronozone (ca. 6965–6650 cal. BP), TOC and TN decreased while δ 13 C had high values, which probably reflected a more distinct stratification of the water column with anoxic bottom waters. Next, in the late Atlantic and early Subboreal chronozone (ca. 6650–5205 cal. BP) the amount of OM in palaeolake sediments was still rising. The δ 13 C values dropped, suggesting an intensification of processes of water mixing. These processes were simultaneous with the constant shallowing of the palaeolake and the disappearance of habitats suitable for submerged macrophytes. The topmost part of the profile is characteristic of a strong decomposition of peat, causing a release of carbon dioxide and therefore the depletion of the carbon pool in the peat (a drop in the C/N ratio). The concurrent upward trend of the δ 15 N curve is probably the effect of a greater anthropogenic impact on the palaeolake/mire and its catchment and/or more recent human interference in the topmost peat layers.

L'Arbreda Cave is one of the southernmost of the Reclau Caves (Serinya, Girona, northeastern Iberian Peninsula), located between the west margin of the Pla d'Usall and the Serinyadell river, at an altitude of about 211 m a.s.l. The Pla d'Usall forms part of the Banyoles-Besald Basin, which is bounded by Eocene and Neogene reliefs. It is filled with sediments of Plio-Pleistocene age. The cave is a shelter formed by travertine cascades with a degree of karstification, and contains sedimentary deposits ranging from the end of the Middle Pleistocene to the Early Holocene, thus constituting an important archaeo-palaeontological record for an understanding of the prehistoric occupation of northeastern Iberia. It is one of the most complete and best-dated terrestrial sequences in Iberia from the Mousterian to the Early Holocene period. In this paper we present a palaeoenvironmental and palaeoclimatic reconstruction of the sequence based on non-flying small mammals (insectivores and rodents) and pollen analyses. The environmental and climatic results, together with the absolute dating of the sequence and direct comparison with NorthGRIP delta O-18 and the sea-surface temperatures (SST) of the Alboran Sea, allow us to identify various climatic periods within our sequence: a cold period between interstadials 12 and 10 in Level I, probably interstadial 10 in Level H-2 the Last Glacial Maximum (LGM) in Levels C and B, the Bolling-Allered interstadial (B/A) in Level A, and the Preboreal/Boreal (Pr/B) in the Terra Rossa Level We want to thank the editor Dr. Paul Hesse and the three reviewers (Prof. Gloria Cuenca-Bescos and two anonymous) for their comments that improve the final version of the manuscript. This paper is part of the projects HAR2013-48784-C3-2-P, CGL2012-38358 and 2014-SGR900. Excavations ara funded by "Conselleria de Cultura Generalitat de Catalunya". J.M. Lopez-Garcia is a beneficiary of a Beatriu de Pinos postdoctoral fellowship (2011BP-A200001) from the Generalitat de Catalunya, a grant co-funded by the European Union through the Marie Curie Actions of the 7th Framework Program for R + D

The transition from Late Palaeolithic to early Mesolithic cultures is strongly associated with the major environmental and climatic changes occurring with the shift from the Younger Dryas to the Holocene in northern Europe. In this paper, we present an interdisciplinary study combining archaeological and palaeoenvironmental research in an attempt to examine the relationship between environment and culture during this transition. Lundby Mose is a former kettle hole lake in southern Denmark where the earliest Danish human traces of the Holocene were excavated. Two types of bone deposits were found, 1) ritual offerings of worked, marrow-split elk bones and antler and 2) settlement waste with multiple species. These date to the early Holocene and are affiliated to the early Maglemose culture. The modelled 14 C ages suggest that the bones were deposited in four phases. A pollen based palaeoenvironmental reconstruction suggests that the ritual offerings were deposited in an environment of limited, underdeveloped forest with unstable soils and areas of open grassland. The settlement waste deposit is associated with a more developed Preboreal forest type. This forest type was not fully established until c. 11,250 cal BP and if substantiated by further evidence, may be one of the reasons why there are no known early Maglemose/Preboreal settlement sites in southern Scandinavia.

The margins of mainland Europe, and especially those areas coming under the influence of North Atlantic weather systems, are ideally placed to record changing palaeoclimates. Cores from an infilled lake basin at Crudale Meadow in Mainland, Orkney, revealed basal deposits of calcareous mud (‘marl’) beneath sedge peat. Stable isotope, palynological and molluscan analyses allowed the establishment of palaeoenvironmental changes through the Devensian Lateglacial and the early Holocene. The δ18Omarl record exhibited the existence of possibly four climatic oscillations in the Lateglacial (one of which, within event cf. GI-1c, is not often commented upon), as well as the Preboreal Oscillation and other Holocene perturbations. The cold episodes succeeding the Preboreal Oscillation were demarcated conservatively and one of these (event C5, ∼11.0 ka) may have previously been unremarked, while the putative 9.3 and 8.2 ka events seem not to produce corresponding palynologically visible floristic changes. The events at Crudale Meadow are consistent with those recorded at other sites from Britain, Ireland and elsewhere, and can be correlated with isotopic changes shown by the Greenland ice cores. The multi-proxy approach enriches the environmental reconstructions from the site, although the synchronicity of the response of the various proxies is sometimes equivocal, depending upon the time period concerned, taphonomy, and the nature of the deposits. The site may contain the most northerly Lateglacial isotope record from northwest Europe, and it has yielded one of the best archives for the demonstration of abrupt early Holocene events within Britain.

On the basis of a comprehensive study of soil-sedimentary sequences, we reconstructed the history of soils and landscapes development in the central part of the Selenga midland (Kuitunka river basin). For the Late Glacial and Holocene four stages of deposition and soil formation have been identified: Late Glacial (15.0-11.7 kyr BP), Early- (11.7-8.8 kyr BP), Mid- (8.8-4.7 kyr BP), and Mid-Late Holocene (4.7-0 kyr BP). The Late Glacial period is characterized by short-lasting and contrasting climatic changes, leading to frequent successions of the phases of activation of erosion-accumulation processes and soil formation. We identified three phases of pedogenesis and the corresponding stages of climate warming and humidification (14.5-14.1; 14.0-13.3, and 13.0-12.6 kyr BP). Intensification of exogenous processes occurred in the time intervals 15.0-14.5; 14.1-14.0; 13.3-13.0, and 12.6-11.7 kyr BP. During the Early Holocene period the most optimal conditions for soil formation take place in the first half of the Preboreal (11.7-11.0 kyr BP). Later, there occurred an enhancement in climate aridization whose evidence manifests itself as high-carbonate aeolian-colluvial deposits. Pedogenesis in the second half of the Preboreal (11.0-10.5 kyr BP) and during the Boreal period (10.5-8.8 kyr BP) was proceeding in steppe/forest-steppe conditions under warmer and less humid climate in comparison with soils formed in the Late Glacial and first half of Preboreal. The Mid-Holocene and the Mid-Late Holocene periods were distinguished by relatively stable landscape-climatic conditions, implying formation of well-developed soils and stabilization of erosion-accumulation landforms. Two long-lasting intervals of intense pedogenesis (8.8-6.9, and 4.7-0 kyr BP) can be identified. Soil formation was proceeding under steppe vegetation in rather warm and slight moistening climatic conditions. From the Atlantic to the Subatlantic climate became more arid. Activisation of exogenous processes occurred in interval 6.9-4.7 kyr BP.

The Hercynian mountain ranges were islands of mountain glaciation and alpine tundra in a Central European ice-free corridor during the Late Pleistocene. Today they are notable areas of glacial landforms, alpine-forest free areas, peatlands and woodlands. However, our knowledge of the Lateglacial and early Holocene environmental changes in this region is limited. We present a new multi-proxy reconstruction of a mid-altitude environment in the Bohemian Forest spanning this period. A core (5.2 m length) in the Černé Lake cirque (1028 m a.s.l.) was subjected to lithological, geochemical, pollen and macrofossil analysis supplemented by two optically stimulated luminescence (OSL) and 10 AMS radiocarbon dates. We determined the impact of regional and supraregional climate changes on the environment. The two most significant changes in sedimentation during the Lateglacial (17.6 and 15.8–15.5 cal. ka BP) were synchronous with regional glacial chronostratigraphy. Unlike Central European mountain ranges, in the Bohemian Forest the Younger Dryas was not coincident with glacier re-advance, but was a dry, cold episode with low lake levels, which prevailed until the early Preboreal. Plant macrofossils indicate local establishment of Betula nana and Betula pendula/pubescens at 15.4–13.4 cal. ka BP. Comparison with Holocene records from Central Europe shows a similar immigration history of vegetation at mid and higher altitudes. The tree line exceeded an altitude of ~1000 m a.s.l. around 10.5 cal. ka BP and coincided with rapid geochemical changes in the sediment. The 8.2 ka BP event did not have any response in the sedimentary record, but corresponded to stabilization of the Picea abies population and expansion of Fagus. Fagus colonized the Bohemian Forest earlier than other Hercynian mid-mountains, but never predominated in the composition of the forest at higher elevations. Abies alba was the last tree species that immigrated to the study area.

International audience; The environmental conditions of the evolution of chernozems in Central Europe have not been satisfactory explained. In this paper, seven buried chernozems were investigated using near-infrared spectroscopy (NIRS) in order to get information about the former vegetation cover. Near-infrared (NIR) data were collected from organic matter of recent natural grasslands and forests. The spectra from these two groups of soils were perfectly discriminated by a multivariate statistical analysis. The statistical model was applied on the buried soils. There are four types of vegetation development within the chernozems before the burial. Comparison to other paleoenvironmental proxies shows no major contradiction and confirms the potential of the NIRS as a paleopedological proxy. The identified changes of vegetation are from grassland vegetation to forest vegetation and vice versa. These changes bring new data to the discussion about the pedogenesis of chernozems. According to the radiocarbon dating, buried soils developed and were preserved not only in the Preboreal and the Boreal, but also in later phases of the Holocene.

A variety of studies of the re-examined (new exposure) Late Pleistocene key section Cheremoshnik (East European plain, middle of the Volga Basin of Yaroslavl) was conducted on a new methodological level using modern methods. For the first time, a series of paleosols (MIS5–MIS1) from the section offering significant information in regard to chronostratigraphy and landscape evolution have been studied in detail and dated. An excavation ∼7 m deep reveals a soil-sediment stratum which formed over the course of ∼115 ka in an accumulative beam-like terrace and consists of five lithological layers and six pedostratigraphical units. The base of the section was determined to be an Early Mikulino peat-dark humus paleosol which marked incipient subaerial pedogenesis on the Moscow (Riss II) moraine and was covered with a thickness of gyttja with a peat horizon (Histosol) which had formed 114–115 ka and was reliably dated using uranium–thorium dating. The following paleosols were successfully identified within the series of weak stone gullied-channel sediments within the Valdai (Wűrm) thickness (from bottom to top): (1) Bryansk paleosol (MIS3) – Gleysol – with three pedogenesis rhythms; (2) Trubchevskaya paleоsol – Gleyic Turbic Cryosol (MIS2) and (3) pedosediment formed at the end of the Bӧlling interstadial (MIS2). Terminal Pleistocene formations are marked with a gravelly stratum on the section's surface formed during the Preboreal period. Recent Regosol formed on loess-like loam deposits was identified at the top of the whole soil-sediment stratum. The 14C age of the paleosol humus varied between 27,500 and 11,400 cal. BP. The paleosols represent the northernmost occurrence of MIS5–MIS2 fossil soil in Europe, dominated by features of gleyzation, cryogenic aggregation, cracking, and humus and peat formation. Pollen analysis results allowed estimation of changes in vegetation cover, climatic conditions and the age of deposit sedimentation for the period from the Moskow Late Glacial to the Valdai Late Glacial and early Holocene times. Successive stages in the development of vegetation, high contents of alder and hazel pollen and the climax and distinct appearance of broadleaf trees relate the formation of biogenic sediments (LPAZ 2–6) in the Cheremoshnik section to the Mikulino Interglacial. Valdai (MIS4–MIS2) glacial sediment is absent within the investigated area.

Here we present the results of the first cryptotephra investigation of two Late glacial-Holocene lake records from the Southern Carpathian Mountains in Romania, Lake Brazi and Lake Lia. The discovery of an important Icelandic tephrostratigraphic marker, the Askja-S, in the sedimentary records of both sites significantly extends the known ash dispersal from this Plinian eruption. Bayesian age-depth modelling of available radiocarbon (14C) data from both sedimentary records allows us to further refine the depositional age of this ultra-distal tephra. In combination with age constraints on the tephra from other well-dated European sites, we produce an updated age for this key tephrostratigraphic marker of 10,824 ± 97 cal yrs BP (95.4% range). The Askja-S tephra is stratigraphically positioned after the palaeoenvironmental proxy response to the Preboreal Oscillation at both sites. The widespread distribution of this tephra across Europe offers the potential to assess spatio-temporal variability of this climatic signal. The discovery of the Askja-S in lake records from the Southern Carpathians highlights the likelihood of finding other ultra-distal (Icelandic) cryptotephra marker layers within the region. Additionally, given the location of the Carpathian region, it offers the opportunity to further enhance and integrate tephrostratigraphic frameworks of north-western Europe with those of the Mediterranean and Anatolia regions, which will enable a more precise comparison of palaeoenvironmental archives across Europe.

International audience; Functional aspects of lithic arrowheads of the GS-1 / Preboreal transition : Comparative approach of terminal ballistics of the trapezoidal bitruncatures and straight back (Blanchères) points

International audience

We describe a sediment sequence comprising a thick till covered by thin beds of lacustrine sediments containing pollen and plant macrofossils derived from pioneer vegetation. Four consistent radiocarbon dates on terrestrial plant remains from the lacustrine sediments yielded an age of 10,500 calibrated years BP (cal years BP). This is the first accurate and precise age obtained for the deglaciation of the Mjøsa region in eastern Norway. We estimate that the ice-margin retreat rate in this area was about 250 m per year. Light-demanding herbs and Hippophaë rhamnoides were the first to colonise locally. When soils matured, birch immigrated to the area forming the first forests at around 10,200 cal years BP. This was rapidly followed by pine and aspen and, later, by black alder at c. 9000 cal years BP. The lacustrine sediments are covered by 50 cm of peat and capped by a two-metre thick, coarse-grained, debris-flow deposit. The latter was surprising because of the very gentle slopes, four degrees in the failure area and less than three in the run-out and depositional area. We propose that the landslide, postdating the top of the peat that is dated to 6360 cal years BP, was triggered by a strong earthquake. publishedVersion

First high-resolution micropaleontologic investigation was carried out for bottom sediments of the Cheshskaya Bay (SE Barents Sea) and marine beds exposed in abrasive terrace along the eastern coast of the Kanin Peninsula. Sediments from 2 gravity cores and a 7.5-m thick terrace section were analyzed for pollen and non-pollen palynomorphs (NPP), including spores, freshwater green algae and cysts of marine dinoflagellates. The age of the sediments was constrained by the reference to the regional sea-level history from the earliest Holocene to present, thus the pollen records reveal the environmental history for the last ca. 10.0 ka. Sparse treeless vegetation with dwarf Betula and halophytic inhabitants of seaside watts (cereals, wormwood and sedges) indicating arctic desert environment with colder and drier than present climate dominated the Cheshskaya Bay coast during the early Preboreal period. Gradual advance of shrubby-birch and piny forest-tundra with alder communities along river valleys resulted from significant climate amelioration which concurred with the Pholas inundation since the Boreal period. Postdated expansion of tree-birch inland the Kanin Peninsula and firry-birch light-forests along the Cheshskaya Bay coast marked the Holocene regional climate optimum. Re-establishment of the dwarf-birch and piny forest tundra signalized vegetation feedback to the cooling since the end of Atlantic period.

The local landscapes of Early Mesolithic–Neolithic settlements within the Upper Volga outwash plain are reconstructed based on the investigation of the multilayer archaeological sites Minino 2 and Zamostye 5, Moscow district, Russian forest zone according to former descriptions by the authors (Vandenberghe et al., 2010). Regional environments in the different stages of the Holocene beginning from the Preboreal, are considered using pollen data while local landscapes (including relief, soil, vegetation and water regime) are reconstructed on the base of sediments, fossil soils and macrofossils, as preserved in a series of burial pits of different age. Colonization of the area by hunters–fishermen followed the local proglacial lake filling and shallowing at the end of the Lateglacial – Postglacial period, about cal 12.0–12.2 ka BP. Drying landscape inherited sharply undulating topography where elevated dry sites were populated up to a flooding episode between cal 2.5 and– 2.8 ka BP, or about 850 BC. Water receded between 1.7 and 1.9 cal ka BP, while large-scale peat accumulation and wetland expansion began about 650–700 BP. During the Holocene depressions had been gradually filled with organic deposits reflecting change of hydrological regimes; the most significant wetting occurred about cal 5.3–5.4 ka BP. Soil evolution has proceeded from initial calcareous alkaline soils to leached acid soils and further to peaty soils.

It is well known that environmental conditions from the Late Pleniglacial to the Preboreal fluctuated abruptly. To explain lithic technological and human behavioral change for this period, the influence of environmental changes driven by climatic fluctuation should be addressed. This paper discusses human adaptive responses to environmental change during the Pleistocene-Holocene transition (19,000 ~ 10,000 cal BP) in the Japanese archipelago, compiling radiocarbon ages that have recently accumulated throughout this archipelago and analyzing diachronic and interregional variability of lithic technology, its organizational characteristics, and its role in reflecting human responses to environmental change. Through these analyses, we consider human behavioral variation within the context of paleoenvironmental changes during this transitional period.

High-resolution Early Holocene palynological records from the middle Meuse River valley were missing until recently. In order to investigate environmental and inferred climate changes during the Preboreal, sediments from a former residual channel of the Meuse River near Haelen were studied. Detailed multi-proxy analyses, including microfossils, macroremains and loss-on-ignition measurements, were carried out at a high temporal resolution. An accurate chronology of the >1000-year-long record was provided by accelerator mass spectrometry (AMS)14C wiggle-match dating.The channel was abandoned during the late Younger Dryas, when accumulation started with gyttja. This period was characterised by an open landscape with herbaceous vegetation and dwarf shrubs. Patches of birch were present on the floodplains around depressions and (oxbow) lakes. Some pines survived the cold in sheltered locations. In the residual channel the water was flowing temporarily and aquatic plant communities developed with predominantly submerged taxa and algae. The shores were fringed by willows and sedges and were probably used as a watering place by large herbivores.Following the Late-glacial/Holocene climate warming, dated in the Haelen record around 11,520 cal BP, birch woodlands expanded on the river floodplains and slopes of terraces during the Friesland Phase. Open vegetation with herbs and juniper remained present on the nearby terraces. An increase in the water level of the oxbow lake and seepage of groundwater occurred. Along the shores herbaceous vegetation was present. Around 11,420 cal BP, birch expansion was interrupted by the dry continental Rammelbeek Phase. On the river floodplain and terrace slopes, open grassland vegetation developed and on the terraces, grasslands and open grounds were abundant. In the residual channel the water became stagnant and floating-leaved vegetation developed. At the start of the Late Preboreal, around 11,270 cal BP, a sudden shift to a more humid climate took place and birch forests expanded again on the river floodplains and terrace slopes. Poplar became more abundant in these forests, and birch and poplar swamp forests were present near the site. Pine expanded atc. 11,160 cal BP on the higher sandy and gravelly terraces. During the Late Preboreal a reed swamp developed on the shores of the residual channel.At the onset of the Boreal, around 10,710 cal BP, woodlands, initially with hazel, but later also with oak, elm and lime, started to develop, while pine forest remained present on the higher terraces. Hazel shrubs were growing on the terrace slopes. Birch and poplar forests occurred on moist parts of the floodplains. Around the residual channel they formed a zone behind the reed swamps surrounding the oxbow lake. Vegetation with water lilies was present in open water.The Haelen record shows, despite a lack of archaeological evidence, indications for the presence of Mesolithic people in the area during the Preboreal. These include the occurrence of (natural or man-made) fires, in combination with the presence of trampled areas and disturbed grounds and possibly consumption of Nymphaeaceae seeds and tubers.

Abstract. Deglacial (12.8–10.7 ka) sea-level history on the East Siberian continental shelf/upper continental slope was reconstructed using new geophysical records and sediment cores taken during Leg 2 of the 2014 SWERUS-C3 expedition. The focus of this study is two cores from Herald Canyon, piston core SWERUS-L2-4-PC1 (4-PC) and multicore SWERUS-L2-4-MC1 (4-MC1) and a gravity core from an East Siberian Sea Transect, SWERUS-L2-20-GC1 (20-GC). Cores 4-PC1 and 20-GC were taken at 120 m and 115 m modern water depth, respectively, only a few meters above the global last glacial maximum (LGM, ~ 24 kiloannum (ka)) minimum sea level of ~ 125–130 meters below sea level (mbsl). Using calibrated radiocarbon ages mainly on molluscs for chronology and the ecology of benthic foraminifera and ostracode species to estimate paleo-depths, the data reveal dominance of river-proximal species during the early part of the Younger Dryas event (YD, Greenland Stadial GS-1) followed by a rise in river-intermediate species in the late Younger Dryas or the early Holocene (Preboreal) period. A rapid relative sea-level rise beginning roughly 11.4 to 10.8 ka (~ 400 cm core depth) during is indicated by a sharp faunal change and unconformity or condensed zone of sedimentation. Regional sea level at this time was about 108 mbsl at the 4-PC1 site and 102 mbsl at 20-GC. Regional sea-level during the YD was about 40 to 50 meters lower than those predicted by geophysical models corrected for glacio-isostatic adjustment. This discrepancy could be explained by delayed isostatic adjustment caused by a greater volume and/or geographical extent of glacial-age land ice and/or ice shelves in the western Arctic Ocean and adjacent Siberian land areas.

Lacustrine organic sediments were sampled at Gronowo (Chelmno Plateau) and Piotrkowo (Dobrzyn Plateau) located within a widespread system of subglacial channels separated by the large Drweca ice-marginal valley. They have been examined for their pollen, plant macro-remains and geochemistry, as well as radiocarbon-dated. The analyses have allowed reconstructing the evolution of the area and presenting an asynchronous appearance of two lakes. Before lake sedimentation, glaciolimnic sediments from the end of Plenivistulian, at the site of Piotrkowo, was dated. Lacustrine sedimentation started during the AllerÝd at Gronowo, and during the Preboreal at Piotrkowo. The different age of the two lakes is ascribed mainly to differences in the Late Glacial drainage conditions which directly affected the melting away of dead-ice blocks buried in the channels.

Significant baseline and episodic megaflooding from glacial Lake Agassiz was routed to the south, east and north coasts of North America over the lake’s nearly 6000 year history. The five phases of lake-level change were controlled by which outlet was active, which in turn was controlled by ice margin position and glacioisostatic adjustment. The southern outlet is the oldest and best understood outlet, while successively younger outlets are progressively less understood. Eastern drainage synchronous with the Younger Dryas chronozone had been assumed by most studies, but a spillway to accommodate the ∼90 m drop in lake level is yet to be described. With the south and east outlets unable to accommodate the necessary lake level drawdown, the northwest outlet has become the default outlet with Arctic Ocean Core data supporting it. However, extant terrestrial data from the continent only provides data for a large flood from the Fort McMurray area closer to the end of the Younger Dryas, coinciding with the timing of the Preboreal Oscillation. The challenge remains to find agreement between the marine and terrestrial records. Uncontroversial is the geomorphic and sedimentologic evidence for flooding into and out of the lake consisting of large spillways, large boulders, and in places giant current ripples composed of boulders. Flood discharge estimates into and out of the lake range from 0.04 to ∼1 Sv, with final subglacial drainage into the Tyrell Sea estimated at ∼5 Sv, sufficient to raise global sea level by 0.18 m and initiate the 8.2 ka stadial.

An increasingly important source of annually resolved palaeoenvironmental proxy data originates from cross-dated incremental chronologies summarizing the shell growth of several individuals. Here, we have analysed annual increment variations in a collection of radiocarbon-dated shells of ocean quahog (Arctica islandica) from early Holocene prodelta deposits in north Norway. Radiocarbon dating of the shell material showed that the increments were formed contemporaneously during Preboreal times. The biologically youngest shell contains 35 annual increments, whereas the oldest shell shows 169 increments. Time-series of annual increments demonstrated clear age trends with the widest increments during the very early years of bivalve life, followed by a notable decline in increment widths as the bivalves aged. Subsequent to removing these biological trends from the series, a sclerochronological cross-dating was carried out and resolved the temporal alignments of the shell growth increment records relative to each other. The resulting shell growth increment chronology evidences vigorous growth variations. Spectral analysis of the chronology revealed 3.7- and 4.3-year periodicities, indicative of Preboreal environmental oscillations. Periodicities of longer period were not detected. Our results prove the value of radiocarbon-dated shell assemblages to build "floating" geochronologies for periods and regions where dead shells from museum collections or seabed are not obtainable. Increasing constructions of such chronologies enhance the potential of sclerochronological cross-dating of annual shell growth increment chronologies to depict and detail annually-resolved climate variability not only for late Holocene, as previously illustrated, but also for early Holocene times, when large-scale oscillations punctuated the global climate dynamics. Development of longer chronologies with higher sample replication remains an attainable interdisciplinary target. (C) 2014 Elsevier Masson SAS. All rights reserved.

Sixteen sites yielding radiocarbon dated brown bears from Alpine regions of Austria are described. Samples have been dated by the AMS-method. For each find, a description of the site, dating and the context of the find are given. The time frame of the finds ranges from Preboreal to the Middle Ages. The climatic context and palaeobiological aspects are discussed. There is no correlation between altitude of the site and chronological age of the bear remains. Comparative data suggest the majority of bears in Alpine cave sites are females. Remains of Holocene brown bears were found in denning caves and in natural pits. Hence, they are bears that did not survive the winter or bears that fell into a natural shaft.

Few places worldwide experienced Late Glacial ecological shifts as drastic as those seen in the areas covered by, or adjacent to, the massive ice sheets that blanketed much of the northern hemisphere. Among the most heavily glaciated regions, northern Europe underwent substantial ecological shifts during and after the Last Glacial Maximum. The climatically unstable Pleistocene–Holocene transition repeatedly transformed far-northern Europe, placing it among the last regions to be colonized by Paleolithic societies. As such, it shares paleoenvironmental and archaeological analogues with other once glaciated areas where human populations, entrenched in periglacial environments prior to glacier retreat, spread into newly deglaciated territories. Perhaps most significant for northern Europeans were post-glacial effects of the Younger Dryas and Preboreal periods, as shifts in climate, plant, and animal communities elicited several adaptive responses including innovation, exploration, and the eventual settlement of once glaciated landscapes. This paper is a detailed review of existing archaeological and paleoecological evidence pertaining to the Late Upper Paleolithic of northern Europe, and offers theoretical observations on human colonization models and ecological responses to large-scale stadial and interstadial events.

The article provides a brief description of the main genetic types of Quaternary deposits and landforms within the GBF, with respect to special features of the territory associated with a significant stretch from North to South. In terms of its geomorphological structure, the territory falls into four parts which differ significantly in relief structure and composition of Quaternary deposits. Glacial, glaciofluvial and glaciolacustrine deposits of the last Scandinavian Late Valdai/Weichselian glaciations, with thickness ranging from 0 to 60 meters and mean values of 3-10 meters, prevail in the structure of the Quaternary cover. Holocene deposits are represented by peat, lacustrine, alluvial and seismo-gravita-tional sediments. The latter are developed locally within paleoseismic displacements. Continental ice was retreating from the study area from the end of the Alleröd (12.3-11.3 Ka B. P.) to the beginning of the Preboreal time (10-9.5 Ka B. P.), wherefore modern landforms were shaped by various processes at different times, leading to a high variety of genetic types of Quaternary deposits and landforms. Earthquakes occurred in some moving parts of the GBF territory in postglacial time as a result of glacial isostatic equilibrium, leaving behind numerous evidence of paleoseismic displacements. The unique geological nature monuments in each of the four parts require further detailed study. It is of high relevance in connection with the special interest in borderland and protected areas, the ongoing development of a number of environmental protection and natural heritage preservation measures.

The results of an integrated study of Late Glacial and Holocene lake-mire deposits on Andoma Ice-divide Upland, located in the Fennoscandian Crystalline Shield-Russian Plate contact zone, are reported. The geomorphological structure of the study area isdescribed. The data obtained show that it was not until the Alleröd, i. e. much later than the Late Valdai glacier had retreated from the study area, that a lake began to form in what is now a mire. This delay was due to some distinctive features of the early deglaciation stages at which dead ice blocks and massifs were formed. The stagnated ice continuedto melt until Boreal time. Terrigenous sediments accumulated in the proto-lake in Late Glacial and Preboreal time. They were rapidly succeeded by organic deposits about 7700B. P. Boreal deposits are assumed to have been completely eroded after the dead ice block damming the lake had completely thawed. As the water level of the lake declined,the lake basin began to get overgrown and peat formation continued. The plant cover development lagged much behind the glacial retreat because dead ice massifs persisted for a long time. The vegetation dynamics from Late Glacial time to the present has been reconstructed. In Late Glacial time, the study area was occupied by tundra dwarf arctic birch-true moss paleocommunities. Open birch woodland, succeeded by sparse birch forests, formed in Preboreal time. Birch forests, succeeded by birch-spruce south-taiga forests, grew in the study area in early Atlantic time. As the climate cooled down at the Atlantic-Subboreal time boundary, spruce and spruce-pine mid-taiga forests began to spread. The contribution of birch increased by the end of the Subatlantic Period.

Thick lake sediments discovered in the southern part of the Czech Republic provide a high-resolution archive for detailed study of paleoenvironmental changes during the Late Pleistocene to Holocene in eastern-central Europe. Until recently, no similar records were available for this important region in the transition from oceanic to continental macro-climatic settings. Using a multi-proxy approach that combines sedimentological, pollen-analytical, paleozoological (Chironomids), geochemical and mineral-magnetic methods we demonstrate that major climatic events of the Late Glacial can be correlated with Atlantic rather than continental regimes as reported in paleoclimatic literature for the area of the interest. The sensitivity of applied biological and abiological techniques to climatically-driven processes allows trans-regional comparisons and enables us to discuss the pattern of geographic variation in these processes. We are able to establish a clear relationship between vegetation cover, soil development and erosional processes. A short-term intra-Allerod cool event has been correlated with the Gerzensee oscillation. Proxy evidence suggests that the early half of the Younger Dryas was rather humid, whereas the latter half was dry and had significant impact on vegetation, sedimentary dynamics and lake level status during the YD/Preboreal transition.

As a source region of North Pacific Intermediate Water, the Okhotsk Sea plays an important role in the ventilation of the North Pacific. To understand the detailed oceanographic changes in this marginal sea since the last glaciation, we studied decadal to centennial scale proxy records from new sediment cores from the southwestern Okhotsk Sea. Glacial to Holocene Δ14C records of benthic foraminiferal shells suggested enhanced ventilation in the Okhotsk Sea during the early deglacial period between 18 and 15 ka, corresponding to Heinrich Event 1. Although the Δ14C reconstruction has considerable uncertainties, the Okhotsk Sea may have acted as a source for vigorous ventilation of the subarctic Pacific during this period. CaCO3 preservation events appear to be better explained by the ventilation history of the Okhotsk Sea than by coccolithophores and foraminifera production. CaCO3 preservation started to improve during 18 to 15 ka, and pronounced peaks in the CaCO3 content corresponded to the Bolling–Allerod (15 to 13 ka) and Preboreal (11.5 to 10 ka) warm periods. Diatom and coccolithophore productivity remained low in the Okhotsk Sea throughout the glacial to deglacial periods, different from the situation in the open subarctic Pacific, where high productivity was observed during the Bolling–Allerod period. After the Preboreal period, biogenic opal gradually increased and δ15N decreased in the southern Okhotsk Sea, suggesting that productivity was enhanced by a relaxation of the nitrate limitation.

In order to elucidate a continuous Holocene high resolution record of past variability of Atlantic water inflow and sea ice distribution, we investigate in this study a marine sediment core (JM09-KA11-GC) from the Kveithola Trough, western Barents Sea margin which is influenced by the north flowing North Atlantic Current (NAC). The depth-age model for JM09-KA11-GC was constructed from 9 14C AMS dates and shows sediment accumulation rates from 0.04 to 0.67 mm yr−1, enabling a sub centennial resolution for most of the core. Planktic foraminifera, stable isotopes and biomarkers from sea ice diatoms and phytoplankton were analysed in order to reconstruct subsurface temperatures and sea ice distribution. Throughout the early part of the Holocene (11 900–6900 cal yr BP), the foraminiferal fauna is dominated by the polar Neogloboquadrina pachyderma (sinistral) and the biomarkers show an influence of seasonal sea ice. Between 11 300 and 11 100 cal yr BP, a clear cooling is shown both by fauna and stable isotope data corresponding to the so-called Preboreal Oscillation. After 6900 cal yr BP the subpolar Turborotalita quinqueloba becomes the most frequent species, reflecting a stable Atlantic water inflow. Subsurface temperatures reach 6 °C and biomarker content indicates open water with mainly ice-free conditions. During the last 1100 cal yr BP, biomarker abundances and distributions show the re-appearance of low frequency seasonal sea ice and the planktic fauna show a reduced salinity in the subsurface water. No apparent temperature decrease is observed during this interval, but the rapidly fluctuating fauna and biomarker distributions indicate more unstable conditions.

Over 3000 prehistoric bone and antler artifacts, collected in the late 1930s from the former lakebed of Lake Lubāns, are held by the National History Museum of Latvia. This collection is remarkable not only as one of the largest known assemblages of bone implements in northern Europe, but also in terms of diversity of forms. The most elaborately worked objects include harpoons, often with two rows of barbs and spade-shaped bases, which are believed to date to the Late Paleolithic, and to be among the oldest organic artifacts ever found in Latvia. Four broken specimens were sampled in 2011 for accelerator mass spectrometry (AMS) dating, stable isotope analysis, and taxonomic attribution by ZooMS. The results support the interpretation that these artifacts were made from large cervid bones, and date all four objects to the early Preboreal (mid-10th millennium cal BC). The Lake Lubāns harpoons therefore fall in the same period as similar harpoons from Denmark, northern Germany, and Poland, although only a handful of these have been dated directly. DOI: 10.2458/56.16957

The history of the Lateglacial and Preboreal sedimentary succession from the Store Slotseng kettle hole basin, SW Denmark is presented. A tephrostratigraphical and multi-proxy investigation of the sediments, including stable isotope geochemistry, reveals small- and large-scale changes in the surrounding environment through time. Three distinct tephra horizons are observed. Two of them are identified as the Preboreal Hasseldalen Tephra and the Younger Dryas Vedde Ash. The third was deposited around the Pre-Bolling/Bolling transition. The Preboreal sediments record two significant decreases in authigenic carbonate content. Using tephrostratigraphy the lower one is identified as occurring during the Preboreal Oscillation, while the upper one is contemporaneous with the Rammelbeek Phase, which by some is recognised above the Preboreal Oscillation. This period has not previously been observed in this region. The discovery of the Hasseldalen Tephra in the Store Slotseng basin expands the known southwestern limit of the ash cloud, and increases the area for potential future observations. The Hasseldalen Tephra (c. 11.3 cal. ka BP) was deposited just prior to the Preboreal Oscillation and as such has a large potential for precise correlation and characterization of this short climatic perturbation.

Due to possible aragonite to calcite transformation resulting in alteration in isotopic signatures and a bias in age-dating, aragonite speleothems are often excluded from paleoclimatic archives. However, aragonite stalagmites contain ppm-level uranium content, making them much easier to date, achieving higher age-dating precisions than calcite stalagmites. In this regard, provided aragonite-to-calcite transformation did not occur, aragonite stalagmites are potentially well suited for Holocene climate research, given their climate proxies can be placed into a better constrained chronological framework. In this paper, we present high-precision U/Th dates and O isotopic time series for a 82 cm, long, continuous growth aragonite stalagmite, LH2, from Lianhua Cave, Hunan Province, China, and discuss East Asian Summer Monsoon (EASM) variability for the last 12.5 ka BP (before present). The U/Th-dated delta O-18 sequence with a mean 16-year resolution and the growth rate pattern of LH2 show that EASM experienced a strengthening stage, a strong stage and a weakening stage during the last 12.5 ka. During the YD (12.5-11.5 ka BP), heavy delta O-18 values and low growth rate indicate a weak monsoon period. During the Preboreal (from similar to 11.5 to 10.6 ka BP), delta O-18 values decreased dramatically (similar to 1.94 parts per thousand) reflecting abrupt strengthening of the monsoon. From 10.6 to 4.2 ka BP, the record is characterized by the lightest delta O-18 values and high growth rates, suggesting a strong monsoon period. The summer monsoon weakened substantially after 4.2 ka BP, as inferred from gradually increasing delta O-18 values and decreasing growth rate. Overall, the intensity of the EASM is regulated by summer insolation at 30 degrees N during the last 12.5 ka. Although oxygen isotope fractionation is different between aragonite-H2O and calcite-H2O because of Rayleigh Fractionation Law, the overall temporal pattern of delta O-18 values from aragonite stalagmite LH2 is concordant with other high-resolution Holocene calcite stalagmite records from South China. The comparison among these records shows that the Holocene Optimum was synchronous across Asian continental region influenced by the EASM and Indian Summer Monsoon (ISM), lasting from similar to 10.6 to 4.2 ka BP, as reflected by consistently lighter delta(18)Ovalues among all these records regardless of their latitudinal difference. These records do not support previously reported asynchronism between EASM and ISM. In details, the long-term delta O-18 trend in LH2 is punctuated by a number of centennial fluctuations. For instance, two weak monsoon events occurred at 9232 +/- 57 yr BP and 8137 +/- 21 yr BP, correlating in time with cooling events in Greenland ice cores. The latest weak monsoon event centered at 302 +/- 8 yr BP which is related to the Little Ice Age (LIA). In addition, the monsoon intensity derived from our record also shows a strong connection with latitudinal migration of the Inter-Tropical Convergence Zone (ITCZ) as recorded in the Cariaco Basin sediments. Spectral analysis of delta O-18 values shows that significant peaks match with solar periodicities of 208 yr (de Vries cycle), 86 yr (Gleissberg cycle) or related to Delta C-14 production suggesting shorter-term monsoon variations are forced by solar radiation. Overall, our study suggests that the delta O-18 record in the aragonite stalagmite is highly consistent with those derived from calcite stalagmites, suggesting that aragonite stalagmites are suitable for palaeoclimate reconstruction, especially for the Holocene period, as aragonite calcite transformation has not occurred. (C) 2013 Elsevier Ltd. All rights reserved.

This paper presents the dynamics of sedimentation processes and soil development of a steeply sloping 0-order catchment in the sandy Lower Bunter of the south-western mid-range mountains in the Palatinate Forest (Germany) during the transition period from the Late Glacial to the Early Holocene. Field investigations, chemical, physical, micromorphological and anthracological analyses revealed a complex palaeosol-sediment sequence along the thalweg of a dry valley, where a significant amount of the sediment from the adjacent slopes had been captured. The deposition of aeolian sands in the lowermost sediment layer took place in the early Late Glacial. The subsequent sediments were deposited by slope-wash and aeolian processes. It contains a higher amount of silt and dates from the Allerod. The occurrence of Laacher See Tephra (LST) indicates that this sediment has been near the surface around 12,900 cal. BP. It also shows characteristics of palaeosols similar to the Usselo/Finow soils in north-eastern Germany. In the overlying material, the amount of root remnants, other organic matter and rounded bone fragments possibly indicates the presence of people in this area. On top, alternating reddish brown, coarse to fine sand and small, partly rounded stones with some small intercalated aggregations of humic material rich in charcoal dating to between 11,000 and 12,000 cal. BP were deposited. The layers are overlain by clearly visible and evenly distributed wavy clay-illuviation bands typical for a Luvisol. In the upper metre, a Cambisol has developed. The sediment structure shows typical features of a flash-flood event in the Preboreal. The stratigraphy suggests that phases of sedimentation caused by water and aeolian erosion took place in the Allerod, Younger Dryas, and Preboreal. Discussion considers climate driven natural processes as well as the possibility that the manipulation of forest vegetation by fire through sedentary Mesolithic hunter–gatherer groups created open areas and enabled intensive soil erosion at a local scale.

La dynamique geomorphologique (incision, mobilite laterale, taux de sedimentation) d’une riviere ardennaise (la Lienne) a ete etudiee au niveau d’un secteur de tourbiere de fond de vallee. Ce type de site presente un interet majeur car la morphologie des depots fluviatiles anciens est preservee en dessous des depots tourbeux et l’utilisation des pollens conserves dans la tourbe permet de dater les differentes phases d’evolution de la riviere. La presence de pollens du Dryas recent par-dessus une nappe de cailloutis perchee 1,4 m au-dessus du lit actuel ainsi que de depots tourbeux dates du Preboreal au niveau du lit actuel indiquent qu’une phase d’incision s’est produite a la transition Dryas recent-Preboreal. Le tephra du Laacher See a ete retrouve a l’etat remanie au contact de la nappe de cailloutis perchee, ce qui confirme qu’elle a ete mise en place au Dryas recent, en contexte periglaciaire. La Lienne presentait vraisemblablement des chenaux multiples au Preboreal, puis l’abandon d’un des chenaux, elle s’est deplacee lateralement, ce qui a permis a la tourbiere de s’etendre jusqu’a occuper plus des deux tiers du fond de vallee des l’Atlantique. L’utilisation des scories siderurgiques comme marqueur stratigraphique montre une faible mobilite laterale de la Lienne ainsi qu’un faible taux d’aggradation de la plaine alluviale au cours des derniers siecles.

The northern part of the Mazury Lake District is marked by the presence of a depression described as the Skaliska Basin. At the end of the Pleistocene, the Skaliska Basin was the site of functioning of a thaw lake, within series of laminated clayey sediments were formed. The surface of the clayey sediments was overlain by a sandy fan. Blocks of dead ice underlying the fan and the overlying surface of the clayey sediments were the origin of small isolated water basins. Since the Allerod they were filled with limnic sediments, passing into peats towards the upper part. In order to reconstruct the vegetational history of the Skaliska Basin and the conditions of sedimentation of the lacustrine gyttjas and peats, several sections were obtained from such basins and subjected to examination of plant macroremains, palaeolimnological analysis and AMS dating. Sedimentation of lacustrine sediments began with sands with an admixture of silt and peat. The beginning of sedimentation of lacustrine sands of aeolian origin falls within the Allerod, whereas the end of that process in ca the middle of the Preboreal. Sands are frequently overlain by a strongly decomposed lacustrine dy sediment. Subsequently a sequence of detritus gyttja accumulated. The complex of gyttjas is interbedded with occasional Scirpo-Typheti peats. Sedimentation of lacustrine sediments is followed by accumulation of peats formed within communities with tall sedges. These communities, according to their compoition, correspond to the associations of Cicuto- Caricetum pseudocyperi Boer. et Siss. and Caricetum elatae Koch. The upper part comprises peats resembling the present-day community of Sphagnum centrale, displaying features of a transition bog. Also the occurrence of Eriophorum vaginatum confirms changes towards ombrotrophic conditions. The uppermost part of the sections often comprises heavily decomposed peat with components no longer identifiable by macroscopic analysis.

The sediment sequence from Budzewo (Skaliska Basin, north-eastern Poland) contains cladoceran records beginning from the early Holocene. A total of 33 Cladocera taxa were identified in the entire sequence. The cladoceran fauna of the initial stage of palaeolake history in the Preboreal shows high similarity to early Holocene Estonian and Scandinavian records. Benthic Alonella nana was dominant at that time. After that, probably during the Boreal and early Atlantic periods, Cladocera species diversity increased and planktonic forms (bosminas) became dominant, pointing to a rise of water level. The species composition indicates that the lake was meso- to eutrophic. The lake began to shallow during the middle Atlantic. The process was completed in the Subboreal and the lake transformed into a bog. The fall in water level and finally the terrestrialization of the lake is correlated with similar processes recorded in other sediment sequences in northern Poland, suggesting that this event may have been driven by regional factors such as lower precipitation.

The development of vegetation in the Skaliska Basin has been reconstructed on the basis of palynological analysis and radiocarbon dating (AMS technique) of 6 sites from the late phase of the Bolling- Allerod interstadial complex to modern times. Although the area covers 90 km2, the mosaic character of habitats led to the development of different patterns of vegetation changes during the Late Glacial and Holocene. Only one site located in the eastern part of the Skaliska Basin reflected the ‘pine phase’ of Allerod, and this is the oldest data on vegetation in the Skaliska Basin. Interesting discrepancies were recorded during the Younger Dryas when patches of shrublands with Juniperus were distinct around some of the sites, while steppe with Artemisia was common in others. The beginning of the Holocene brought an expansion of birch-pine forest, but around 9600 cal. BC a cold oscillation took place which was reflected in an increase in birch in the woodlands in the western and eastern part of the Skaliska Basin. In the Preboreal chronozone elm (Ulmus) also expanded in the area but its appearance was non-synchronous. The vegetation of the Boreal chronozone was similar in the whole area and the most characteristic feature was the rapid expansion of hazel (Corylus avellana) which displaced Betula from the most of its sites. At that time a distinct redeposition of pollen material in the Parchatka river valley was detected which was probably the effect of an increase in fluvial activity of the river (humid oscillation). The following stage of vegetation development was climax woodlands with Tilia cordata, Ulmus, Quercus, Corylus avellana, and Alnus in damp places. At the beginning of the Subboreal chronozone the expansion of Quercus took place, which was subsequently replaced by Picea abies and partly Carpinus betulus. The pattern of Picea abies expansion distinctly presents two maxima which is characteristic of many sites in the north-eastern Poland. The Subatlantic chronozone is represented only by the profile from the Skaliski Forest, where, because of sandy ground, Pinus sylvestris was the dominant element. Human impact was poorly reflected through the rare occurrence of pollen grains of Cerealia type in the pollen profiles spanning the time from the Subboreal chronozone to modern times. In most profiles AMS dating produced age discrepancies, which limited the possibility of establishment of a detailed chronology. However, dates obtained from the material contaminated by mixture of glycerine, thymol and ethyl alcohol, pretreated by alcohol, showed reliable results in most cases.

This paper presents the results of palynological, macrofossil and peat analyses that were conducted on deposits from a profile collected from the Wielkie Błoto mire near Bałupiany (north eastern Poland). The investigation revealed that the recorded changes of vegetation span the period from the decline of the Younger Dryas (ca 9600 cal. yr BC) to the late Subboreal or early Subatlantic chronozone, but due to a 40 cm long sediment gap a complete reconstruction was not possible. At the beginning, the area was occupied by steppe and tundra communities together with abundant Juniperus stands. A subsequent expansion of birch (Betula) woodlands with pine (Pinus sylvestris) took place in the Preboreal chronozone in which a rise in the water level and/or basin deepening was recorded at the site as well. The domination of such woodlands lasted to the end of the Boreal chronozone when Corylus avellana expanded rapidly. In the Atlantic chronozone multispecies deciduous forests developed with Tilia cordata and Quercus, while Ulmus together with Alnus spread in damp habitats. During this chronozone, traces of the occurrence of Carpinus betulus were detected in the macrofossil analysis, while the pollen analysis failed to record its presence. The expansion of Carpinus betulus and Picea abies was characteristic of the Subboreal chronozone when both taxa presented antagonistic optima. Alone in north-eastern Poland, there was a re-expansion of deciduous forest in the younger part of the Subboreal chronozone caused probably by low human impact, which is reflected in the whole profile. The first probable traces of human activity were noticed in the Atlantic chronozone and attributed to peoples of the Mesolithic or Early Neolithic cultures, while the first evidence of cultivation was correlated to the Bronze Age. However, the low resolution of the radiocarbon dates did not allow a more precise reconstruction of the chronology. The analysis of macrofossils and tissues indicated two episodes of oligotrophication of the mire. The first one took place during the Boreal chronozone, while the second fall in trophy was triggered by spruce expansion in the Subboreal chronozone. On the other hand, a rise in human impact during the first Carpinus betulus maximum caused eutrophication of the mire.

A new stomatal proxy-based record of CO2 concentrations ([CO2]), based on Betula nana (dwarf birch) leaves from the Hasseldala Port sedimentary sequence in south-eastern Sweden, is presented. The record is of high chronological resolution and spans most of Greenland Interstadial 1 (GI-1a to 1c, Allerod pollen zone), Greenland Stadial 1 (GS-1, Younger Dryas pollen zone) and the very beginning of the Holocene (Preboreal pollen zone). The record clearly demonstrates that i) [CO2] were significantly higher than usually reported for the Last Termination and ii) the overall pattern of CO2 evolution through the studied time period is fairly dynamic, with significant abrupt fluctuations in [CO2] when the climate moved from interstadial to stadial state and vice versa. A new loss-on-ignition chemical record (used here as a proxy for temperature) lends independent support to the Hasseldala Port [CO2] record. The large-amplitude fluctuations around the climate change transitions may indicate unstable climates and that “tippingpoint” situations were involved in Last Termination climate evolution. The scenario presented here is in contrast to [CO2] records reconstructed from air bubbles trapped in ice, which indicate lower concentrations and a gradual, linear increase of [CO2] through time. The prevalent explanation for the main climate forcer during the Last Termination being ocean circulation patterns needs to re-examined, and a larger role for atmospheric [CO2] considered.

Krotovinas, the burrows of small mammals, are common phenomena in steppe landscapes, and for a long time they have been a major point of discussions about the genesis of Holocene Chernozems. In addition, krotovinas provide a very valuable archive of the biological activities of soil, which is essential when stratigraphical ambiguities are to be solved. Despite this, krotovinas have received little attention within pedostratigraphical research. Using the example of the Upper Palaeolithic excavations Kostienki and Borshchevo in the Middle Russian Steppe an integrative soil scientific approach highlights the importance of burrowing small mammals and of krotovina fillings resulting from both bioturbation and soil erosion in the Late Pleistocene. Based on field and laboratory data of sediments inside and outside krotovinas and 14C dating results from two sections, this systematic approach demonstrates the high value of the burrow fillings: black and humus-speckled fillings belong to deep burrows of hamsters dating to the period of Early Holocene Chernozem formation at the very beginning of the Preboreal (10–8 ka cal BC). Greyish sediments originate either from Ag–Bg horizons of the “Gmelin soil” (25–22 ka) or from other as yet unknown Late Valdai paleosols; these fillings are the result of the activities of shallow-burrowing lemmings. In addition, burrow fillings have provided optimal material for worms. Also, fossil bones and teeth found within krotovina fillings give new insights into the occurrence of Cricetus cricetus and Lagurus lagurus in this part of the Middle Russian steppe.

Modern lake hydrodynamics, ostracode species autecology, stable isotopes (δ 18 O and δ 13 C) of multiple ostracode species, ostracode taphonomy and sediment geochemistry were studied to improve interpretation of the late Pleistocene–early Holocene (∼24–10 ka) stable isotope record of ostracodes in sediment core PI-6 from Lago Peten Itza, northern Guatemala. Oxygen and carbon stable isotopes in modern and fossil species assemblages of Lago Peten Itza were used as indicators of changes in the balance between evaporation and precipitation, past lake level and carbon source. Ostracode taphonomy was used to detect past periods of strong currents, high-energy environments, and possible partial or full mixing of the lake. The modern lake water isotopic composition displays clear seasonal differences that are independent of lake level fluctuations. Modern benthic species displayed lower δ 18 O and δ 13 C values than nektobenthic species, with differences of 3.0‰ and 5.3‰, respectively. Valves of nektobenthic species display higher values of δ 13 C because these ostracodes live in shallower environments among abundant algae and aquatic plants, where productivity is high. The benthic species Limnocythere opesta Brehm, 1939 displayed the smallest average offset from δ 18 O water (+0.3‰) and the largest offset from δ 13 C DIC values (−4.1‰) among studied ostracode species. Nektobenthic species Heterocypris punctata Keyser, 1975 displayed the smallest difference relative to the δ 13 C DIC values (−0.1‰). Late Pleistocene–early Holocene climate conditions and water levels in Lago Peten Itza can be summarized as follows: 1) high lake levels and cold conditions (Last Glacial Maximum [LGM], ∼24–19 ka), 2) fluctuating lake levels and cold conditions (Heinrich Stadial 1 [HS1], ∼19–15 ka), 3) high lake levels and warm and wetter conditions (Bolling-Allerod [BA], ∼15–13 ka), 4) low lake levels and dry conditions (Younger Dryas [YD], ∼13–11.5 ka) and 5) high lake levels and warm and wetter conditions (early Holocene, ∼11.5–10.0 ka). Average lake level fluctuation in Lago Peten Itza during the late Pleistocene–early Holocene was as much as ∼25 m. Ostracode analyses suggest that the LGM was characterized by relatively low δ 18 O (+4.7 to +6.0‰), and δ 13 C values (−7.1 to −6.4‰) in ostracode valves, high inferred water depths and high percentages of broken adult and juvenile valves (>66%), suggesting a high-energy environment, strong currents, partial to full mixing, downslope transport, colder water temperatures and wetter conditions. An increase in the relative abundance of the benthic species L. opesta and higher numbers of broken valves suggest heavy precipitation events during the LGM (∼23.7, 21.7, 20.8 and 20.1 ka). HS1 was predominantly dry, but we identified times when lake levels were slightly higher, at the onset of the deglacial and a brief period (∼17–16 ka) between HS1b and HS1a. All studied climate proxies indicate wetter and warmer conditions and lake system stability during the BA. Lake levels dropped during the YD and gradually increased during the Preboreal and early Holocene. We demonstrate that modern and fossil ostracode isotopic signatures, species assemblages and taphonomy can be used together with physical and geochemical variables in Lago Peten Itza sediments to make high-resolution inferences about late Pleistocene–early Holocene environmental changes in the lowland Neotropics.

A new pollen record from Valle di Castiglione near Rome (core VdC09) has been studied with the aim of providing a detailed reconstruction of the vegetation history of the Roman landscape between 13,800 and 7700 cal BP, in response to the Lateglacial and early Holocene climate events. An open landscape dominated by steppe vegetation characterized the Lateglacial, so that only a modest increase of trees took place during the Allerod interstadial. The Intra Allerod Cold Period induced instability in the development of the woody communities. The Holocene forest recovery started around 11,600 cal BP, but definite forest development occurred only around 11,100 cal BP, at the end of the Preboreal Oscillation, which produced an important re-expansion of herbs. The evergreen Mediterranean vegetation was constantly present in the landscape, even during the Lateglacial cold fluctuations. A clear early Holocene increase in evergreen trees corresponds to the attainment of high and stable values in the GISP2 δ 18 O curve, around 10,200 cal BP.

This study aimed to reconstruct environmental changes in the Wkra River Valley near Bielawy Goluskie (central Poland) based on geochemical, palynological and subfossil Cladocera analysis of deposits filling a palaeo-oxbow lake. Two sediment boreholes collected from the palaeochannel bend (BG-1) and neck (BG-2) include full sequences of organic deposits lying on clastic deposits. The lower part of the BG-1 borehole contains gyttja that accumulated during the Younger Dryas and the Preboreal, which is covered by reed peat of Preboreal and Boreal age. On top of this is alder peat that accumulated during the Atlantic. The ages of the gyttja and peat were confirmed by both radiocarbon dating and palynological analysis. The peats are characterized by a significant content of organic matter, which is relatively stable over time. This indicates a low intensity of mechanical denudation in the catchment, which is supported by low concentrations of aluminum and potassium. Calcium values greatly exceed these elements, suggesting that the lake was mainly fed by groundwater. Variation in trophic conditions over time is indicated by a vertical variability in the content of nitrogen, as well as by the Cladocera population. The strong decomposition of peat in the top layer of the mire, and increased concentrations of phosphorus and heavy metals, testify to increasing human activity during the most recent time periods