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Detailed knowledge of the periglacial flora is essential to assess the vegetation dynamics in deglaciated regions of northern and north eastern Europe, previously covered by the ice sheet of the Late Weichselian Glaciation. Therefore, the territory of Belarus, which stretches in the periglacial zone of the Last Glaciation and the most part of which was free of ice during the Last Glacial maximum, is off particular importance in analysing the postglacial floral establishment and the subsequent vegetation dynamics in this part of the continent. In this study, results of palaeobotanical (pollen and plant macrofossil), lithological (measurements of magnetic susceptibility, MS) and isotopic (14C) investigations were obtained to fill the existing gap in reconstructing the peculiarities of the terrestrial and aquatic vegetation dynamics throughout the Lateglacial - Early Holocene period in the central Belarus. The investigated sediment profile, comprising organically enriched gyttja at 13,400–13,100 cal yr BP, carbon enriched and sandy gyttja at 13,100–9700 cal yr BP and unconsolidated mud after 9500 cal yr BP, provides clear evidence proving the flourishing of a pine-birch predominated forest with occasional spruce stands during the Allerod in area. Three occasions of change in the vegetation structure were noted within the Younger Dryas, i.e. 12,900–12,700 cal yr BP, 12,200–12,000 cal yr BP and 11,900–11,700 cal yr BP, suggesting negative climatic excursion taken place in area and facilitating flourishing of a Picea-predominating forest that culminated at about 12,300 and 12,000 cal yr BP. Pollen record suggests the Early Holocene vegetation shifts occurring at about 11,300–11,200 cal yr BP, 10,800–10,600 cal yr BP and 10,300–10,100 cal yr BP evidence the general response to the global-scale climatic events i.e. Preborael Oscillation or “10,2 ka” while fluctuations triggered by local or regional-scale climatic events have been identified as well. About 10,800–10,700 cal yr BP, formation of the forest with an increasing representation of thermophilous taxa (Ulmus, Tilia, Quercus) started in area.

With the discovery of peat and gyttja deposits containing archaeological remains, sealed below a colluvium, at Fuglsøgaard in eastern Jutland in 2002 came a rare opportunity to investigate a bog with abundant traces of peat cutting and subsequent ritual deposition dating to the Early Iron Age. Pollen analyses show that before, during and after the ritual deposition, the bog lay in an open cultural landscape surrounded by arable fields and pastures. Around180 cal B.C., extensive peat extraction commenced in the bog, targeting the well-humified wood peat that had formed during the Atlantic period and could be found in the deeper layers.In this relatively tree-less area, the primary aim of the peat cutting was presumably the acquisition of fuel. It is estimated that 250-500 m2 of peat was removed, leaving the bog with numerous small water-filled pits, i.e. peat cuts.These water-filled peat cuts had a secondary role as elements in ritual activities in which depositions were made of pottery vessels, parts of domestic animals, wooden objects, bundles of flax, quantities of white/light-coloured stones etc. More than 130 pottery vessels from period II of the Pre-Roman Iron Age (250-1 cal B.C.) have been excavated at the site. 14C dates for Linum usitatissimum (common flax) stems in two pottery vessels assign the depositions tothe period 180-1 cal B.C. All the depositions included white/light-coloured stones, and these appear to have been a general feature of many ritual depositions in wetlands at this time.As the peat cuts in the bog became overgrown, due to renewed peat accumulation, the depositions decreased and there appears to have been a clear link between the offerings and the presence of open water into which these could be lowered. During the entire period of use (i.e. peat cutting and deposition), the bog appears to have been open and without tree cover,presumably due to persistent grazing and/or haymaking. But at the turn of the millennium, the bog had lost its ritual significance and its surface became colonised by willow scrub. With the discovery of peat and gyttja deposits containing archaeological remains, sealed below colluvium, at Fuglsøgaard in eastern Jutland came a rare opportunity to investigate an Iron Age votive bog with abundant traces of peat cutting and subsequent ritual deposition. Pollen analyses show that before, during and after the votive phase, the bog lay in an open cultural landscape surrounded by arable fields and pastures. Around 180 BC, extensive peat extraction commenced in the bog, targeting the well-humified wood peat that could be found in the deeper layers. It is estimated that 250-500 m2 of peat was removed, leaving the bog with numerous small water-filled pits, i.e. peat cuts. These water-filled peat cuts then had a secondary role as elements in votive activities in which ritual depositions were made of pottery vessels, parts of domestic animals, wooden objects, bundles of flax, quantities of white/light-coloured stones etc. More than 130 pottery vessels from period II of the Pre-Roman Iron Age (250-1 BC) have been excavated at the site. All the depositions included white/light-coloured stones, and these appear to have been a general feature of many ritual depositions in votive bogs at this time.

Lammefjorden is a reclaimed fjord in north-west Sjælland, Denmark. Sediment cores from the area were collected to study its development after the last deglaciation, in particular the sea-level history. Late glacial and Early Holocene lake and bog deposits occur below marine deposits. Sparse late glacial fossil assemblages indicate tree-less environments with dwarf-shrub heaths. Early Holocene deposits contain remains of Betula sec. Albae sp. and Pinus sylvestris, which indicate open forests. The wetland flora comprised the calciphilous reed plant Cladium mariscus and the water plant Najas marina. Marine gyttja from basins is characterised by sparse benthic faunas, probably due to high sedimentation rates. In some areas, shell-rich deposits were found, with large shells of Ostrea edulis, indicative of high summer temperatures, high salinity and strong tidal currents. A marine shell dated to 6.7 cal. ka provides a minimum age for the marine transgression of Lammefjorden.

The studied Radymno loess section is located in the large, fore-Carpathian San River valley (Sandomierz Basin, SE Poland) and shows the sequence building the Pleistocene cover of middle terrace of the San River. Such sequence is quite rare in loess deposits because it combines different depositional environments: subaqueous – the late Eemian-Early Vistulian alluvial-swamp facies of loess with inserts of gyttja type, and subaerial – the Plenivistulian aeolian loess. The main goal of the study was to reconstruct the Late Pleistocene paleoenvironmental changes recorded in this section. For this purpose, pollen and fossil Ostracoda analyses were conducted. These data were supplemented with sedimentological and pedo-lithological analyses. Additionally, the results of earlier investigations published so far have been used: lithological and malacological analyses as well as luminescence (IRSL and TL) dating. Based on the analysis of many indicators, the paleoenvironmental changes have been correlated with those recorded in pollen diagrams obtained from other regions. This correlation indicates that in the Radymno section there is evidence of the vegetation succession typical of the Eemian Interglacial with climatic optimum and of the short-term oscillations in the Early Vistulian and then in the Lower Pleniglacial of Vistulian. The analysis of fossil Ostracoda, which were found in some parts of the profile, provided information about short-term paleohydrological changes, and especially about the functioning of surface water bodies in changing periglacial conditions of the bottom of the San River valley in MIS 5d – MIS 2. High humidity in the environment was caused mainly by floods and high groundwater level, which indirectly conditioned the formation of water bodies in the valley bottom. Correlation with palynological data indicated that these water bodies existed also under dry climate conditions. This proves that the local conditions of the studied area strongly modified the environmental changes dependent on paleoclimate.

A number of interglacial sections discovered in the eastern part of Lithuania and suggested as Snaigupėlė Interglacial were attributed to the Saalian Complex Stage of Middle Pleistocene. However, the exact stratigraphical position and correlation of these interglacial sections are still arguable. Recent investigations were performed to get a clearer insight into the stratigraphy and sedimentation palaeoenvironment of the Snaigupėlė Interglacial sediments outcropping in Buivydžiai section and included complex proxies: pollen, plant macrofossils, diatoms, loss on ignition, magnetic susceptibility and optically stimulated luminescence dating. Interglacial sediments occur at the lowermost part of the exposure and reach more than 7 m thick. Palaeobotanical investigations confirm deposition of studied sediments during the different climatic stages of the interglacial. An attempt at correlation between the Buivydžiai section vegetational changes with vegetational succession obtained from north-central Europe allowed finding out some similarities with the Schoningen/Lublinian Interglacial. The OSL dating results do not contradict such a proposition as the two sand samples lying below the interglacial gyttja show sedimentation of this layer during the 300.5 ± 20.9 ka and 317.3 ± 21.8 ka time or MIS 9. However, recently obtained data are insufficient for grounding the correlation of studied section. Certainly, additional chronostratigraphic investigations would be valuable and may contribute to the solution of the sediment age and correlation problem.

The last British-Irish Ice Sheet (BIIS) created a landscape with many sedimentary basins that preserve archives of paleoenvironmental and paleoclimatic change during the Last Glacial-Interglacial Transition (LGIT; ~ 18-8 ka BP). The typical lithostratigraphic succession of these archives is composed of minerogenic/allogenic sediments formed during cold climatic conditions and organic-rich/authigenic sediments during warmer climates. This paper presents a multi-core lithostratigraphy compiled from the extant lake and surrounding basin at Llangorse Lake, south Wales, a basin lying within the southernmost limits of the last BIIS. This lake contains one of the longest continuous terrestrial sediment successions in the UK. Uncertainty previously existed concerning the presence and distribution of sediments at the site related to the Windermere Interstadial (~ 14.7 to ~ 12.9 ka BP) and Loch Lomond Stadial (~ 12.9 to 11.7 ka BP). A new borehole survey demonstrates that LGIT-age sediments are present at the site with nekron mud (gyttja), corresponding to the Lateglacial Interstadial, deposited in the deeper part of the lake waters and that these deposits are equivalent in age to marl deposits found at shallower depths at the margins of the basin. These deposits are associated with warmer conditions experienced during the Windermere Interstadial and Holocene, whilst minerogenic-rich sediments were deposited during the colder climatic conditions of the Dimlington Stadial and the Loch Lomond Stadial with rangefinder radiocarbon dates confirming this attribution. A model of lake level changes shows that drainage of the Dimlington Stadial glacial lake caused the largest fall, but there was also a further, smaller lake level fall at the end of the Windermere Interstadial and/or the start of the Loch Lomond Stadial, before the level rose in the early Holocene. The lithostratigraphic results presented here form the framework for further paleoenvironmental and paleoclimatic research at Llangorse Lake.

This paper presents the first result of a study of two long-term natural archives in the southwestern part of the Western Siberian Plain. Bchron age models based on 17 AMS dates allowed us to determine a chronology of changes in properties of lake and peat deposits. Significant changes in the Holocene were identified according to geochemical indices, accumulation rates, and compositions of the plant macrofossils of sediment cores in Lake Kyrtyma and Oshukovskoe peat bog. Sediments with a low content of organic matter and maximum weathering accumulated in the Late Glacial, below the border of the Holocene. The transition to the Holocene manifested as a black organic gyttja with ostracods and marked warming ∼12–11.2 ka BP. At about 11.2–10.1 ka BP it was replaced by the Preboreal oscillation. Subsequent changes in lake sedimentation were associated with general warming and an unstable hydrological regime. An increase in humidification ∼8.2 ka BP was reflected by lake level rise and contributed to swamping of the watersheds. The aridest Holocene phase at ∼7.1–5.5 ka BP was reliably recorded by geochemical data, but poorly reflected in the stratigraphy of both profiles. Subsequent cooling and the resulting decrease in evaporation began at ∼5.5–4.9 ka BP. A pronounced cardinal shift in sedimentation conditions due to a gradual increase in precipitation was recorded at ∼4.9–2.8 ka BP, though short-term fluctuations towards dryness were also marked at ∼3.5–3.3 ka BP. The most significant increase in humidification and cooling began at 2.8 ka BP. Geochemical indices in the lacustrine sediments are climate sensitive and allowing us to obtain enough reliable data associated with changes in sedimentation environments. The stratigraphy of peat reflected the nuances of climatic changes less clearly and primarily demonstrated the stages of bog self-development; however, sphagnum peat provided a better-resolution record.

Here we present results of high-resolution palaeoecological studies of the organic deposits accumulated in Lake Jaczno, located in the north-eastern Poland. Plant macrofossils and malacological analyses complimented by radiocarbon dating (AMS) were undertaken to reconstruct Early Holocene succession of the pioneer wetland plants and molluscs in the lake ecosystem. Numerous presence of charcoal pieces (>1 mm) and fungal remains (sclerotia) in the peat layer accumulated on the mineral ground document dry habitat what coincides with warm and dry climate conditions in the early Holocene recorded in this part of Europe. Change to lacustrine environment documented by accumulation of the carbonate gyttja on the highly decomposed peat layer took place ca. 10,500 cal yr BP. The current morphology of Lake Jaczno, in which several basins can be distinguished, suggests that different age of sediments accumulated at the bottom part at our sampling sites might result from different sizes of the buried dead ice blocks, and their heterochronous final melting. The first aquatic plants that appeared in Lake Jaczno were Chara sp., Ceratophyllum demersum and Nymphaea alba. The appearance of Cladium mariscus in Lake Jaczno ca. 9400 cal yr BP was synchronous with the substantial spread of this plant in this region which coincided with increased climate humidity. The first molluscan species that colonized the lake ecosystem were Gyraulus crista and Bithynia tentaculata, species living on macrophytes, and Valvata piscinalis, typical for habitats characterized by a thick layer of plant detritus.

Publisher's version (útgefin grein)., Sediment cores from Kløverbladvatna, a threshold lake in Wahlenbergfjorden, Nordaustlandet, Svalbard were used to reconstruct Holocene glacier fluctuations. Meltwater from Etonbreen spills over a threshold to the lake, only when the glacier is significantly larger than at present. Lithological logging, loss-on-ignition, ITRAX scanning and radiocarbon dating of the cores show that Kløverbladvatna became isolated from Wahlenbergfjorden c. 5.4 cal. kyr BP due to glacioisostatic rebound. During the Late Holocene, laminated clayey gyttja from lacustrine organic production and surface runoff from the catchment accumulated in the lake. The lacustrine sedimentary record suggests that meltwater only spilled over the threshold at the peak of the surge of Etonbreen in AD 1938. Hence, we suggest that this was the largest extent of Etonbreen in the (mid-late) Holocene. In Palanderbukta, a tributary fjord to Wahlenbergfjorden, raised beaches were surveyed and organic material collected to determine the age of the beaches and reconstruct postglacial relative sea level change. The age of the postglacial raised beaches ranges from 10.7 cal. kyr BP at 50 m a.s.l. to 3.13 cal. kyr BP at 2 m a.s.l. The reconstructed postglacial relative sea level curve adds valuable spatial and chronological data to the relative sea level record of Nordaustlandet., Sveinn Brynjólfsson and Sara Mollie Cohen are thanked for field assistance. Fieldwork and radiocarbon dates were funded by the Carlsberg Foundation (CF14-0756 to Schomacker) and Department of Arctic Geology, The University Centre in Svalbard (UNIS), respectively. Geospatial support was provided by the Polar Geospatial Center, and DEM(s) were created from DigitalGlobe, Inc., imagery and funded under National Science Foundation awards 1043681, 1559691, and 1542736. We thank Ole Bennike, Svend Funder, Antony Ruter, and Peter Ilsøe for macrofossil identification and lab assistance. The manuscript benefited from constructive review comments from Andy Emery. The publication charges for this article have been funded by a grant from the publication fund of UiT The Arctic University of Norway.

This study presents the first application of micromorphology and Automated Scanning Electron Microscopy (ASEM) to a submerged shell-bearing midden site in Denmark, one of the few submerged shell-matrix sites in the world to have undergone archaeological excavation. The use of micromorphology in these deposits provides a means to distinguish primary and secondary deposits and degree of preservation. The additional input of quantitative mineral analysis provides an empirical tool for correlation of minerogenic components across the site and assessing change through time. Micromorphological insights into the formation history and post-depositional modification include epizootic infestations within oyster shells at the base of the profile and needle-fibre calcite at the top - the former is indicative of accumulation of at least part of the shell midden below water, whilst the latter is indicative of exposure. Aside from the shell itself, other cultural traces include heated and worked flint fragments, burnt and unburnt hard bone fragments (including fish bone), soft (spongy) bone, charcoal (Ulmus sp., Alnus sp., Corylus sp.), and preservation of what could possibly be antler velvet. Quantitative mineral analyses provide support for the successive stabilisation of the midden site by accumulating minerogenic (silica-rich) sands over the glacial clay and detrital gyttja deposits (defined by smaller grain size, greater heavy mineral content), and subsequently between the shell matrix itself, until the erosion of these protective sediments in more recent times. Further micromorphological profiles are needed to fully assess local versus regional signatures within the site, which otherwise provides an ideal context against which to compare the effects of inundation in similar microtidal contexts.

The application of electrical resistivity tomography to peatlands supports conventional coring by providing data on the current condition of peatlands, including data on stratigraphy, peat properties and thickness of organic deposits. Data on the current condition of drained peatlands are particularly required to improve estimates of carbon storage as well as losses and emissions from agriculturally used peatlands. However, most of the studies focusing on electrical resistivity tomography surveys have been conducted on natural peatlands with higher groundwater levels. Peatlands drained for agriculture have not often been studied using geophysical techniques. Drained sites are characterized by low groundwater levels and high groundwater fluctuations during the year, which lead to varying levels of water saturation. To validate better electrical resistivity tomography surveys of drained peatlands, the aim of this laboratory study is to investigate the influence of varying water saturation levels on electrical conductivity (reciprocal of resistivity) for a variety of peat and gyttja types, as well as for different degrees of peat decomposition. Results show that different levels of water saturation strongly influence bulk electrical conductivity. Distinct differences in this relationship exist between peat and gyttja substrates and between different degrees of peat decomposition. Peat shows an exponential relationship for all degrees of decomposition, whereas gyttja, in particular organic‐rich gyttja, is characterized by a rather unimodal relationship. The slopes for the relationship between electrical conductivity and water content are steeper at high degrees of decomposition than for peat of low degrees of decomposition. These results have direct implications for field electrical resistivity tomography surveys. In drained peatlands that are strongly susceptible to drying, electrical resistivity tomography surveys have a high potential to monitor the actual field water content. In addition, at comparable water saturations, high or low degrees of decomposition can be inferred from electrical conductivity.

This study presents 1) the results of a stable isotope and subfossil Cladocera analyses of lacustrine sediments from Maliszewskie Lake (E Poland) and next 2) different reaction of the lake environments depending on the lake's localization. Maliszewskie Lake is located in North Podlasie Lowland ca. 30 km to the south of the Vistulian ice sheet limit. The approximately 4.80-m-thick sediments (Maliszewo I profile) are mainly comprised of calcareous gyttja covered by peat and organic detritus gyttja. Pollen analysis documents that the sediments accumulated from the Late Glacial (Allerod period) to recent times. Based on the results of stable isotope and subfossil Cladocera analyses of sediments, the lake environmental changes were reconstructed. A positive trend in δ18O and δ13C values documents a gradual climatic warming. The fluctuations of the oxygen isotopic values suggest the multiple oscillation of water level due to a change in the evaporation/precipitation ratio. The subfossil cladoceran fauna in the Maliszewo I profile is represented by 21 species belonging to five families. Three zones of Cladocera development were distinguished. The Cladocera species indicate the initial oligotrophic status of the lake and its subsequent increase of trophic status. Currently, Maliszewskie Lake is a very shallow, declining reservoir. The initial period of its existence probably saw its maximal depth. In presented studies we compared our results with data from three other sites documenting the reaction of the lake environment during the Late Glacial and Holocene transformation. At that time we observed different reactions to the climate amelioration. In the northern, postglacial lakes, the Holocene warming at first provoked an input cold melting water characterized by more negative oxygen isotope values and then a rise in water temperature. In the lakes further away from the glaciation border (periglacial lakes), the increase in water temperature, documented by e.g. more positive oxygen isotopic immediately occurred. The climate warming is commonly manifested by a significant increase of number of species and individuals of Cladocera.

While recent landscape changes can be usually easily read through accessible morphological features, relatively ancient processes can be difficult to detect as the associated morphologies and deposits are often buried below younger sediments. With the aim of understanding the evolution of the distal Venetian-Friulian Plain (NE Italy) after the Last Glacial Maximum (LGM), this work presents the analysis performed on a dataset of ca. 2300 mechanical and hand-made cores, which allowed a detailed reconstruction of the formation and evolution of an incised valley, now almost completely filled and with little to absent morphologic expression. Such valley, up to 1.2 km wide, with a depth of 20 m below the LGM alluvial plain and traced for a length of 25 km, is the result of the complex interplay between minor spring-fed rivers and the Tagliamento River. The detailed characterization of the infilling allowed to identify two main phases in the valley evolution. The first one is related to the activity of the paleo Tagliamento River and led to the deposition of a 10 m thick gravelly unit (ca. 19–9.5 ka cal BP). The second phase, which followed a disconnection of the Tagliamento, is linked to the Holocene marine transgression and led to the formation of a lagoon environment within the valley and to the deposition of a ca. 15 m thick unit of lagoon muds (ca. 8 ka cal BP - historic time). This latter unit lays on top of gyttja deposits, indicating for the first time in this area the presence of widespread lacustrine environments in the Early Holocene. This work presents an in-depth analysis on the evolution of a distal plain incised valley, from its formation to its final filling, providing at the same time the means to describe the development of the entire alluvial plain landscape, spanning from the end of the LGM to the middle Holocene. We present new data on the paleoenvironmental and morphologic evolution of the Venetian-Friulian Plain area as a consequence of the interplay between autogenic forces and sea-level rise. Our study allowed to understand the importance of both Alpine rivers and groundwater-fed streams in the formation of large incised valleys in the coastal sector of the whole Venetian-Friulian Plain. Finally, as during the transgressive phase the upstream sediment input in the valley was almost absent, this study provides insights into facies and architecture of a rare example of downstream-controlled filling of an incised valley.

We present a case study of a bog showing how an integrated approach of multi-method geophysical sounding and local soil sampling can be used to identify, differentiate, and map organic sediments. Our study is based on ground-penetrating radar (GPR), electrical resistivity tomography (ERT) and shear-wave seismic (SH seismic) profiling applied to sediments of the former Lake Duvensee (northern Germany), nowadays a bog. This is a well-known locality for remains from the Mesolithic hunter-gatherers&rsquo, occupation that has been attracting archaeological and geoarchaeological research for100 years. The bog is embedded in low conductive glacial sand and is characterized by layers of different gyttja sediments (detritus and calcareous). The present study was conducted in order to identify the bog morphology and the thickness of the peat body and lake sediments, in order to understand the basin evolution. To validate the geophysical results, derived from surface measurements, drilling, soil analyses as well as borehole guided wave analysis of electromagnetic waves and Direct-Push (DP-EC) have been carried out and used for comparison. It turned out that each method can distinguish between sediments that differ in grain size, particularly between peat, lake sediments (gyttjas and mud) and basal glacial sand deposits. GPR is even able to separate between strongly and weakly decomposed peat layers, which is also clear considering resistivity variations in the ERT computation. From the association between geophysical properties and sediment analysis (e.g., water content and organic matter) different gyttjas were distinguished (coarse and fine) and seismic velocity was correlated to bulk density. Moreover, GPR and SH-wave seismics present different resolutions, confirming that the latter allows measurements, which are more focused on determining the extension of basal sand deposits, the depth of which is difficult to reach with GPR. Representative values of electrical resistivity, dielectric permittivity, and shear wave velocity have been determined for each sediment type and are therefore available to complete the investigation of wetland environments. Fine grained lake sediments were difficult to differentiate by the applied methods. This could be a result of high ionic concentration within the permanent groundwater body, partly masking the sediment properties.

The Rozprza stronghold functioned as a seat of a noble family since at least the early14th century AD in the form of the motte-and-bailey residence. The remains of the residence are situated in the central part of mid-Luciąza River valley, on the river terrace remnant adjoining a strongly expanding floodplain. The situation and state of preservation give a unique opportunity to conduct research that explain the construction process, detailed history of the medieval moat and palaeoenvironmental reconstruction of the valley floor. Radiocarbon and dendrochronological dating and analysis of artefacts confirmed 14th century age of the moat. Organic deposits (gyttja, peat and organic mud) of moat fill allowed for a set of multiproxy analyses based on sediment cores. The research results indicate shallow water with brief episodes of in-wash in the first stage (13th-14th c. AD), followed by a transformation into telmatic habitat in the second phase of the moat development from 16th-17th c. AD. The deposition of overbank alluvium took place within the moat ditch system as late as the 18th and/or 19th c. AD. We studied the development of this moat environment in the context of valley floor changes.

The coastal cliffs in Klaksvik (Borðoyar Bay) are the only known locality with Eemian sediments in the Faroe Islands. Previous studies carried out there focused on the sedimentology, tephra chemistry, paleoecology including aquatic environment, or the age of the deposits. In the lacustrine, clayey to silty gyttja we collected scattered wood fragments, identified as Larix sp., Pinus sp., Taxus sp. and Betulaceae? In addition, these wood remains contain numerous trace fossils, made by marine wood-boring bivalves (Teredolites longissimus), which together with a discussion about the areal extent of the identified tree species leads us to conclude that they are non-native, i.e. driftwood. Northern Siberia is usually regarded as the most likely source area for driftwood in the eastern North Atlantic region. We combined the approximate transport distance from the areal extent of the wood with the main directions of marine currents in the relevant section of the North Atlantic. Adding the known average marine current velocities during the penultimate interglacial resulted in 130–200 days for transport from North America and 350–1100 days from Siberia. Comparing this with the maximal buoyancy period for the identified tree species, we conclude that the Faroese driftwood may originate not only from Siberia, but also from the eastern coast of North America, especially from the region around the Great Lakes, as well as from western Europe. (Less)

The preconsolidation stress is an important phenomenon that determines the value of stress history exerted in the past on the subsoil in the geotechnical engineering. Overconsolidation ratio (OCR) is one of the main criteria conditioning soil behaviour and its characteristics. Here thought, the yield stress ratio (YSR) is used to determine the value of preconsolidation stress resulting from mechanical overburden than can be changed by many post depositional processes like secondary and tertiary compressibility, cementation, aging, temperature change and others. The yield stress ratio (YSR) is defined as the relationship between vertical yield stress (σ’vy) to the effective vertical stress (σ’v0). The eemian gyttja was used as a foundation in the engineering construction. In practical geotechnical engineering, evaluation of stress history is usually based on the overconsolidation ratio (OCR). The yield stress ratio (YSR) was used in the laboratory as one of the basic parameters for the geotechnical design of the structure. To know the relation between geological background, history and mechanical behaviour in long-time process of the soil aims a knowledge that can help engineers who often have to predict soil behaviour based upon the soil geological history and a few geotechnical data. In order to evaluate the yield stress ratio of eemian gyttja it is necessary to restore this soft, organic soil as much as possible to the in situ conditions. The laboratory tests were used to determinate the vertical yield stress and then the yield stress ratio. The laboratory tests were made in the automatic oedometer and the in situ tests were carried out on the dilatometer test (DMT). The comparison between the determination the yield stress ratio of eemian gyttja from the laboratory and the overconsolidation ratio from in situ test has been done. The studies have shown that the values of the overconsolidation ratio determinate from the laboratory tests are a little higher than determinate from the in situ tests.

Several shallow lakes have been drained to make way for additional arable land or pasture in the Mazurian Lakeland (NE Poland) since the 19th century. As a result of these hydrotechnical works, the water level usually decreased by approximately 6 m. Bottom sediments of the former lakes were transformed into surface limnic soils. Part of them, developed from highly calcareous gyttja, may be called limnic rendzinas. However, the present position of these soils in the Polish Soil Classification is unclear. Where the lake has undergone a natural terrestrialisation, the gyttja is covered with peat and mursh. The raw gyttja soils differ in type of organic matter forming the topsoil horizon and are subject to further transformation, the direction of which depends on the sequence of sediments in the profile, mursh formation, mineral admixture and adjoining colluvial phenomena. Common features of all these soils are high content of calcium carbonate in the surface horizons, alkaline reaction, high groundwater level and periodical flooding. The paper presents the variability of limnic rendzinas based on many examples from the Mazurian Lakeland (NE Poland). Finally, new type additions were suggested to the next edition of the Polish Soil Classification.

The Radom Plain is a region with numerous fossil palaeolakes that formed a palaeolakeland. Lacustrine sediments of thickness varying from 0.5 to 18 m were encountered in numerous boreholes. Pollen analyses of the sediments filling the palaeolakes have proven that their sedimentation began after the retreat of the Saalian ice-sheet (MIS 6), continued during the Eemian Interglacial (MIS 5e), and terminated at the beginning of the Weichselian Glaciation (MIS 5d). Climate and palaeoenvironmental changes have been recorded in different deposits: muds, peats and gyttja. Local factors, such as reservoir depth, and geological conditions have influenced the type of the accumulated sediments. Eemian sites occur in two geomorphological positions: in small depressions on the glacial plateau and in small valleys in ox-bow palaeolakes. Eemian lakes were formed from the melting of dead-ice blocks. Pollen data obtained from the palaeolake sediments document climate and vegetation changes characteristic of the Late Glacial period, the Eemian Interglacial, and the beginning of the Weichselian Glaciation. In many sites, a record of a complete Eemian succession is present, whereas in others it is fragmentary. Comparison of pollen data between the Radom region and other localities in Poland shows local and regional differences in the development of forest communities in the Eemian. In the Eemian sequences of the Radom Plain, a considerable contribution of Tilia , Picea and Abies pollen is distinct in the forest communities, often higher than in other Eemian sites of Central Poland. The particularly high percentage of Tilia (exceeding 30%), Picea (up to 67%) and Abies (30%) pollen are recorded in the Babin site. This phenomenon may indicate favourable environmental and climate conditions, facilitating further propagation of these trees. In the pollen record from the Babin site, three distinct abrupt/cool climate oscillations have been noted, with the oldest one recorded in the Saalian Glaciation. The two younger oscillations have been distinguished at the very beginning and at the very end of the Last Interglacial, respectively. Eemian sites from the Radom Plain are important for the reconstruction of palaeoenvironmental and palaeoclimate changes in the Eemian Interglacial in Poland and Europe.

Five sections of sediment from mire infillings located in different part of the catchment small river valley in central Europe were studied by lithological and geochemical analysis in order to examine the response of aquatic ecosystems to the environment changes during Late Weischselian (LW). Differentiation of geochemical composition and grain-size properties in biogenic deposits is being considered as a result of change hydroclimatic conditions and geology structure in individual parts of the catchment. The principal component analysis (PCA) and clustered by hierarchical method (HCA) were chosen to create the lithogeochemical facies and their chronostratigraphy variability. Biogenic sediments of the studied river mires, regardless of the location in a given reach of the valley, are represents mainly by mineral or organic-mineral lithogeochemial facies with increased of lithophilic elements (Na, K and Mg). Similar chemical composition of gyttja and peat sediments in almost all periods of LW, indicate the strongly mechanical denudation processes in the Grabia River valley. The major process, conditioning the development of the mires (in it type and rate sedimentation), was the variable terrigenous material input which are related to its variable dynamic of floods. The higher than expected chemical denudation probably a result of specific groundwater flow direction and dissolving vari-grained sands and silts, which build plains in the central part of the study catchment. The number and thickness of individual lithogeochemical facies are caused by differences in the potential volume of the hydrologically active zone and geological conditions of the emerge or disappear permafrost.

In several road projects in western Norway, it is common to encounter a soil consisting of mineral soils with an organic part and high water content. The organic soil is referred to as gyttja and the organic part originates from remains of plants and animals rich in fats and proteins. It is common to find up to 14 m thick soil layers containing gyttja. The amount of organic content is much lower than peats however this is observed to significantly alter the engineering property of mineral soils involving clay and silt. However, there exists no systematic study on characterization of strength and deformation properties of gyttja in Norway. As a result, it is a common practice to excavate and replace such soils. However, this shall not be a viable engineering solution as removal of organic soils gives a significant CO2 emission. This implies that it is important to find ways to deal with such types of soils apart from always replacing them. To achieve this, it is essential to establish engineering properties for characterization of strength and deformation behaviour of gyttja. This research work thus focuses on looking at these aspects based on extensive field and laboratory tests. Effect of cement as a stabilization method to improve strength is also experimentally looked at. Results are also compared with available data from literature documenting other countries experiences with organic soils. This work presents and discusses main trends, correlations and characteristics related to strength and deformation behaviours of Norwegian gyttja.

The overconsolidation ratio of eemian gyttja determination. The overconsolidation ratio is an important parameter that determines the value of stress history exerted in the past on the subsoil in the geotechnical engineering. Overconsolidation ratio (OCR) is one of the main criteria conditioning soil behavior and characteristics. To know the relation between geological background, history and mechanical behavior of the soil, aims a knowledge that can help engineers who often have to predict soil behavior based upon the soil geological history and a geotechnical data. In order to evaluate the overconsolidation ratio of eemian gyttja, it is necessary to restore this soft soil as much as possible to the in situ conditions. The eemian gyttja is an organic soft soil from the “Zoliborz channel” located in Warsaw. These soils are used as a base construction in the foundation engineering. In practical geotechnical engineering, evaluation of stress history is based on the overconsolidation ratio. The overconsolidation ratio is one of the basic parameters for the geotechnical design of the structure. Determination of this parameter using for example dilatometer tests, is usually based on empirical formulas which were established in different countries. Therefore, regional geotechnical conditions could have substantially affected on the empirical relationships. The laboratory tests are used to determinate the preconsolidation pressure and then the overconsolidation ratio. The laboratory tests were made in the automatic oedometer and the in situ tests were carried out on the dilatometer test (DMT). The paper presents results of determination the overconsolidation ratio of eemian gyttja from the laboratory and in situ tests. The studies have shown that the values of the overconsolidation ratio determination from the laboratory tests are a little higher than determination from the in situ tests.

Diatoms and sediments were examined in a 530 cm core from Ishiba Ngandu, Zambia, a lake formed by gentle downwarping. Diatom zone D (>20 cal ka BP) was mostly sand with abundantAulacoseiraandEunotia, suggesting a shallow lake perhaps kept fresh by spring inputs and lake discharge, except during deposition of the lowermost 66 cm. Gyttja deposition between about 22 and 20 cal ka BP suggested a deeper lake and a wetter climate, perhaps because the Congo Air Boundary (CAB) was farther southeast relative to modern times. The next zone, zone C (about 20–19 cal ka BP), was sand with abundantAchnanthidiumandEunotiabut very few planktonic diatoms, apparently representing very shallow water and an arid period without the CAB. The gyttja and diatoms in zone B (19–4 ka) suggested an increase in moisture when the CAB returned. Zone A (4–0 cal ka BP) was dominated by the planktonicAulacoseira(>89%), suggesting an increase in wind-driven mixing. Uniquely, Ishiba Ngandu likely has been relatively moist since the last glacial maximum, matching pre-Holocene wetness in Botswana but not its Holocene aridity; evidently the climate here had switched to that of East Africa.

This article presents the results of a comprehensive geochronological study of gyttja deposits from a section of a terrace above a floodplain located on the right bank of the Ob River near the town of Kolpashevo. According to the 230Th/U dating, the age of the gyttja could be dated in the range of 110–95 kyr. The results of spore–pollen analysis suggest that the gyttja deposit was formed in the period of a wide distribution of middle taiga forest landscapes with the dominance of spruce; the climatic conditions were similar to modern ones. These events probably took place in the interstadial time during MIS-5c or at the end of Kazantsevo interglacial period.

Despite recent progress in understanding high-latitude climate variability, paleoclimate records are scarce from the Alaskan Arctic. We conducted isotopic and sediment analyses at Wahoo Lake to infer Holocene climate variability in northeastern Alaska. Water δ18O and δD values from the lake and its inlet/outlet streams suggest that winter precipitation dominates modern water inputs and that evaporation has limited influence on the lake’s hydrological budget. The isotopic composition of Pisidium exhibits marked variations during the past 11,500 years, with δ18O ranging between −18.7‰ and −16.2‰ and δ13C between −7.1‰ and −2.3‰ (Vienna Pee Dee Belemnite (VPDB)). Elevated δ18O and sediment composition from 11.5 to 8.9 kcal. BP suggest evaporative 18O enrichment and arid conditions. Rising lake levels are evidenced by the disappearance of Pisidium and a transition to low-carbonate gyttja ca. 6.3 kcal. BP and by the onset of sediment deposition on an adjacent shelf by 5.3 kcal. BP. These changes coincided with enhanced effective moisture in interior and southern Alaska as inferred from lake-level records and may be related to broad-scale atmospheric circulation changes. In the shelf sediments, carbonate abundance increases markedly at 3.5 kcal. BP, and δ18O increases from −18.0‰ to −16.5‰ at 2.1 kcal. BP, possibly resulting from increased temperature and/or summer precipitation. After 2.1 kcal. BP, δ18O fluctuates with an overall decreasing trend to −17.2‰ at 0.9 kcal. BP. Late-Holocene variations in our δ18O record display coherent patterns with regional glacier fluctuations at centennial to millennial scales, suggesting that δ18O minima were related to a combination of low temperatures and enhanced winter snowfall. Holocene variations in organic matter abundance at Wahoo Lake also show broad similarities to total solar irradiance, implying that suborbital solar variability played a role in modulating regional climate and aquatic productivity.

For the first time, plant macrofossil analysis supported by detailed stratigraphic studies was used to reconstruct peatland development in South Africa. Two peat cores (4.69 and 1.5 m) from two coastal peatlands in KwaZulu-Natal were analysed for carpological macrofossils, wood and macrocharcoal. The first one, Matitimani, is an unchannelled valley bottom peatland (site VB), and the second one, KwaMazambane, an interdune depression peatland (site ID) further up in the same catchment. Radiocarbon dating reveals the peatland initiation at site VB at about 6260 cal. yr BP. Rising sea level and humid climatic conditions during that time coincide with the formation of organic gyttja (dominantly aquatic seeds like Nymphaea sp.). In ca. 4950 cal. yr BP, a change to drier condition took place, revealed by the formation of radicell peat from Cyperaceae, and an increase of fire frequency (macrocharcoal). After ca. 1200 cal. yr BP, peat swamp forest emerged, with Ficus trichopoda, Syzygium cordatum and Voacanga thouarsii forming wood peat. Site ID dates back to ca. 920 cal. yr BP. Its initiation is assumingly related to reduced drainage capacities of the catchment subsequently to the peat formation in Matitimani valley. A steady change from gyttja forming communities ( Nymphaea sp.– Eleocharis dulcis) to radicell peat-forming Cyperaceae communities took place. The long-term apparent rate of carbon accumulation (LORCA) is higher for site ID (89 gC m−2 yr−1) than for site VB (55 gC m−2 yr−1). Except for the peat swamp forest period, fire occurred frequently at both sites, however less in environments with frequent inundations.

Disturbed lacustrine deposits of eastern Canada have been associated with past seismic events in the intraplate Western Quebec Seismic Zone (WQZ) and the Charlevoix–Kamouraska Seismic Zone (CKSZ). With five major earthquakes that occurred during historical times and hundreds of minor earthquakes, the CKSZ is the most active seismic zone in eastern Canada. Here we present new high-resolution multibeam bathymetric, subbottom profiler and sediment core data collected in Lake Temiscouata, southeastern Quebec, the largest lake located within the influence of the CKSZ. The occurrence of mass-movements in the highly cohesive glaciolacustrine deposits of the lake produced a peculiar lacustrine landscape consisting of steep slide scars and residual mounds and very narrow residual crests. Our data indicate that postglacial times were marked by recurrent seismically-induced mass-movement events that cannot be individually identified in the sedimentary record due to the highly disturbed stratigraphy of the lake and to the absence of significant postglacial background sediments between events. The most recent recorded mass-movement is a distinct debris flow sediment layer on the lake floor that was deposited at ~ 1300 cal BP, very shortly after a distinct large-scale mass-movement event observed across the entire lake basin. The presence of silt layers in gyttja overlying these disturbed units suggests that the region was affected by other seismic events following this event, although no MMDs could be directly related to these layers.

Organic-rich freshwater sediments formed from the remains of water plants, plankton and benthic organisms, which are transformed by microorganisms, and mixed with mineral components supplied from the lake basin, are known as gyttja (sapropel or dy). Gyttja is a valuable natural resource that can be used in various fields such as agriculture, forestry, construction, chemical industry, balneology and the latter ones are especially interested in chemical composition and safety of natural materials. The aim of the study was to investigate micro- and macro-element content of gyttja derived from lakes of eastern Latvia (north-east of Europe). Depending on composition, sediment samples were identified as peaty, various algae, green algae, diatom, carbonate and organic-silicate types of gyttja. Dried samples were wet-digested by heating in HNO3/H2O2 solution until complete mineralization. Sample solutions were analysed by atomic absorption spectrometry (AAS) to detect concentration of Ca, Fe, K, Mg, Mn, Na and Zn, but inductively coupled plasma mass spectrometry (ICP-MS) was applied for As, Ba, Cd, Co, Cr, Cu, Li, Ni, Pb, Rb, Se, Sr and V concentration measurements. Total content of elements was variable; higher macroelement concentration was detected for gyttja of carbonate type, but higher microelement concentration-for organic-silicate gyttja. As concentration of several elements was much lower than permitted by the European Union legislation, gyttja is not only safe, but also highly valuable resource applicable in organic agriculture. There is a potential to use gyttja as a peloid in health care, but element bioavailability should be estimated likewise.

In February 2011, two landslides in which 11 people were killed, occurred in the Collolar open pit mine, situated in the Elbistan Basin in eastern Turkey. In the coalfield, a thick sequence of clay (>100 m) overlies karstic limestone bedrock. These are overlain by deposits consisting of a 20–50 m thick lignite sequence and a 20–50 m thick gyttja sequence. The gyttja is in turn overlain by Quaternary deposits. In this study, we aimed to shed light on the geologic factors that led to the instability and on the precise trigger for the failure. Therefore, we focused on the above Plio-Quaternary lacustrine and fluvial sediments and applied geomorphological, sedimentological, and geotechnical analyses. After establishing the geomorphology of the coalfield and the landslides, we analyzed 38 samples from existing drill cores, 10 surface samples, and 35 undisturbed samples from new boreholes. Our results indicate that the February 2011 landslides were caused by the liquefaction of the organic-rich “seekreide” (low plasticity, Ca-rich marls) layers at the transition between gyttja and unconsolidated, fine-grained Quaternary sediments. We inferred that the trigger for the landslides might be related to changes in the groundwater flow dynamics in and around the coalfield, and that the shaking caused by the first landslide might have contributed to triggering the second landslide. In brief, we conclude that the second landslide at the Collolar coalfield was a unique example of a landslide that did not have typical rotational, spoon-shaped failure planes and retrogressive progression, as previously proposed.

Marine interglacial deposits are fairly common and widespread in Denmark, but so far none have been reported from the Herning area in central Jylland. In 2014, the Geological Survey of Denmark and Greenland (GEUS) received samples at one metre intervals from a borehole at 55°59.3´N, 8°56.6´E (elevation 27.56 m above sea level), at Hesselvigvej 7 near Kibæk in central Jylland (Fig. 1). The succession consisted of Miocene and Quaternary deposits. The Quaternary part was dominated by glaciofluvial sand and a single till bed, but it also contained a marine clay unit (16–21 m depth, 6.5–11.5 m a.s.l.). This marine clay contained spines of the sea-urchin Echinocardium cordatum, a boreal species known from Eemian and Holocene deposits from Denmark, but unknown from interstadial deposits. A lacustrine unit between 26 and 33 m depth (5.5 m b.s.l. to 1.5 m a.s.l.) consisted of clay, calcareous-rich gyttja and diatomite. Because Quaternary marine deposits are unexpected in this part of Denmark, we report here on analyses of pollen from the lacustrine unit and foraminifera from the marine unit, and we compare these with some interglacial records from Jylland.

WOS: 000377882700006, Lake Neor is the largest lacustrine basin in the high mountains of the Middle East, at 2500 m altitude in the Alborz belt. This lake of Holocene age is a shallow, fresh water body of glacial origin with ca 4 km(2) surface area and a 40 km(2) drainage area. Its sedimentary sequence comprised of peat and gyttja consists of >10 m infill, which is fairly thick for such a lake. Autochthonous organic matter is limited in and around the lake except for small areas at the northern and southern ends. Inorganic constituents of the infill sediment include a significant amount of fine-grained calcite, dolomite and mica particles that are exotic to the catchment. They do not occur in the source rocks, as the drainage area of the lake is composed of only andesites and trachyandesites of Eocene age. In addition, the uppermost part of the infill includes abundant fine-grained charcoal particles derived from large forest fires perhaps derived as far as the Mediterranean region. As shown by the present meteorological records, the sediment of Lake Neor is under aeolian control during dust storms; this is leading to a considerable amount of deposition air-borne particles. The infill of some lakes, particularly those in highlands, may have contain an important aeolian component and thus they cannot be used directly for the interpretation of the evolution of the palaeogeography without taking into consideration the role of dust storms on deposition. Crown Copyright (C) 2015 Published by Elsevier Ltd. All rights reserved., Ankara University [12B434002]; [1227], The study has been supported by a research project of Ankara University (no 12B434002). Figures were drawn by Yasar Suludere. Water analyses of the lake were provided by the Ardabil Directorate for Environment Protection of Iran. Stephen Kershaw and Lorna Anguilano from Brunel University London critically read the original version. Mike Turner (Brunel University London) has kindly revised the English of the manuscript. Authors are grateful for all support. The publication is a contribution to the INQUA QuickLakeH project (No 1227).

High resolution X-ray fluorescence (XRF) is presented as a robust palaeoclimatic proxy, suitable for use on Late Pleistocene to Holocene sediments located in a volcanic crater on the Atherton Tableland in northeastern Queensland, Australia. The proxy allows identification of wet and dry shifts in a complex sedimentary sequence comprised of peat, gyttja, laminated organic rich muds and fine clastic silt-rich sediments. Significant correlation is found between the XRF record and other proxies including magnetic susceptibility, humification, grain size, macrocharcoal, δ13C and C/N and pollen. Sixteen wetter periods are identified in the 37 ka sedimentary record for Bromfield Swamp. Three wetter periods commence in late Marine Isotope Stage 3, nine in the early glacial, one in the late de-glacial and four in Holocene. Nineteen drier periods are identified, four in late MIS 3, seven in the early glacial, one during the LGM, one in the late de-glacial period and six in the Holocene. The XRF record for Bromfield Swamp is specifically used to identify periods of abrupt climate change. Marked changes in effective precipitation are detected at 32,690, 30,080, 24,660, 21,870, 11,880, 10,020, 9170 and 5120 cal. yr BP. The detection of these abrupt climate events may allow correlation with records from terrestrial sites across the Southern Hemisphere and potentially, the Northern Hemisphere.

Detrital sediment in Florida's (USA) submerged cave systems may preserve records of regional climate and hydrologic variability. However, the basic sedimentology, mineralogy, stratigraphic variability, and emplacement history of the successions in Florida's submerged caves remains poorly understood. Here we present stratigraphic, mineralogical, and elemental data on sediment cores from two phreatic cave systems in northwestern Florida (USA), on the Dougherty Karst Plain: Hole in the Wall Cave (HITW) and Twin Cave. Water flowing through these caves is subsurface flow in the Apalachicola River drainage basin, and the caves are located just downstream from Jackson Blue (1st magnitude spring, > 2.8 m3 s− 1 discharge). Sedimentation in these caves is dominated by three primary sedimentary styles: (i) ferromanganese deposits dominate the basal recovered stratigraphy, which pass upsection into (ii) poorly sorted carbonate sediment, and finally into (iii) fine-grained organic matter (gyttja) deposits. Resolving the emplacement history of the lower stratigraphic units was hampered by a lack of suitable material for radiocarbon dating, but the upper organic-rich deposits have a punctuated depositional history beginning in the earliest Holocene. For example, gyttja primarily accumulated in HITW and Twin Caves from ~ 5500 to 3500 cal yr. BP, which coincides with regional evidence for water-table rise of the Upper Floridian Aquifer associated with relative sea-level rise in the Gulf of Mexico, and evidence for invigorated drainage through the Apalachicola River drainage basin. Gyttja sediments were also deposited in one of the caves during the Bolling/Allerod climate oscillation. Biologically, these results indicate that some Floridian aquatic cave (stygobitic) ecosystems presently receive minimal organic matter supply in comparison to prehistoric intervals. The pre-Holocene poorly sorted carbonate sediment contains abundant invertebrate fossils, and likely documents a period of enhanced limestone dissolution and cave formation (speleogenesis) during lower paleo water levels. Further work is still required to (a) determine whether precipitation of the ferromanganese deposits is inorganically or biologically mediated, (b) temporally constrain the emplacement history of the primary sedimentary styles, and (c) determine the full geographic extent of these sedimentary signals. However, these preliminary observations suggest that sedimentation in the inland underwater caves of northwestern Florida is related to Quaternary-scale hydrographic variability in the Apalachicola River drainage basin in response to broader ocean and atmospheric forcing.

A unique geological process of extrusion of lagoon marl from beneath massive migrating sand dunes is characteristic for large segments of the Curonian Spit – a ~100-km-long sandy barrier that separates the Curonian Lagoon from the Baltic Sea. Exposures of a composite set of Holocene organic sediments such as gyttja, clayey gyttja and gyttja clay, collectively referred to as ‘lagoon marl’, are common along the northern half of the lagoon coast of the spit. The marl outcrops rise up to 3–4 m above the lagoon level and owe their origin to extrusion from their 7–8 m in situ depth beneath the present regional water table. New detailed investigations of the Baltic Sea bottom along the southern half of the Curonian Spit using side-scan sonar, a multibeam echosounder, seismic imaging, sediment sampling and video observations allowed identification and mapping of a unique underwater landscape formed by extensive outcrops of laminated and folded lagoon marl at water depths of 5–15 m. The combined onshore–offshore database indicates that relict lagoon marl was deformed, compacted and dehydrated by a massive dune-covered coastal barrier migrating landward (retrograding) over these sediments during the Littorina Sea transgression in a processes termed ‘dune tectonics’. Spatial analysis of the relict sediments traced in offshore geophysical data helped to constrain the rates of the southeast migration of the dune massif. A conceptual model is presented to explain the present context of marl exposures above the regional water table, as well as the occurrence of relict lagoon marl extrusions (diapirs) on the underwater marine slope of the Curonian Spit.

Pollen, spore, macrofossil and carbon data from a peatland near Cordova, Alaska, reveal insights into the climate–vegetation–carbon interactions from the initiation of the Holocene, c. the last 11.5 ka, to the present (1 ka = 1000 calibrated years before present where 0 = 1950 CE). The Holocene period is characterized by early deposition of gyttja in a pond environment with aquatics such as Nuphar polysepalum and Potamogeton, and a significant regional presence of Alnus crispa subsp. sinuata. Carbon accumulation (50 g/m2/a) was high for a short interval in the early Holocene when Sphagnum peat accumulated, but was followed by a major decline to 13 g/m2/a from 7 to 3.7 ka when Cyperaceae and ericads such as Rhododendron (formerly Ledum) groenlandicum expanded. This shift to sedge growth is representative of many peatlands throughout the south-central region of Alaska, and indicates a drier, more evaporative environment with a large decline in carbon storage. The subsequent return to Sphagnum peat after 4 ka in the Neoglacial represents a widespread shift to moister, cooler conditions, which favored a resurgence of ericads, such as Andromeda polifolia, and increased carbon accumulation rate. The sustained Alnus expansion visible in the top 10 cm of the peat profile is correlative with glacial retreat and warming of the region in the last century, and suggests this colonization will continue as temperature increases and ice melts.

The Ełk Lakeland (NE Poland) with the area of 263 100 ha was formed during Vistulian glaciation. More than 66% of this region was shaped during the Leszno phase, 15% during the Poznań phase, and 19% during the Pomeranian phase. There are 1854 fens which cover the area of 7.3 % of the Ełk Lakeland mesoregion. Fens have an area of 10.3 ha on average. About 82.5% of the studied fens is located on gyttja deposits, which suggests post-lacustrine origin of the wetlands. Primary the lakes had covered 11% of the Ełk Lakeland, and 6.3% was transformed into fens. Most of them (60%) was formed on organic gyttja, 16% on calcareous gyttja, and 6% on clay gyttja. About 17.5% of fens was formed as a result of paludification. The types of bedrock underlying peats differ depending on the phases of glaciation.

Multi-proxy studies of the sediment cores and acoustic profiles from Mecklenburg Bay display a more detailed picture of the evolution of the environment in the Holocene. Studies of diatoms, geochemistry, grain size and radiocarbon dating clearly reveal the age and character of freshwater and marine transgressions and regressions. After the final regression of the Baltic Ice Lake, a local lake and swamp environment was recorded by peat gyttja sediments. This environment existed until the Ancylus Lake transgression dated ca 10,500 cal BP. During the Ancylus Lake period, the area remained a shallow-water lake, transitional isolated from the main Baltic Basin. The first slightly brackish marine inflows confirmed by the appearance of planktonic, mesohalobous and halophilous diatoms were identified at the beginning of the Initial Littorina Sea stage and dated ca 8800 cal BP. The boundary between the Ancylus Lake and the Initial Littorina Sea is marked by increasing contents of biogenic silica and iron. The Initial Littorina Sea stage was characterized by increasing mesohalobous and polyhalobous diatom forms and decreasing oligohalobous species. The Initial Littorina Sea environment was recorded as a slightly brackish reservoir sporadically affected by weak marine inflows. The Littorina transgression appeared in the Mecklenburg Bay at ca 7500–7700 cal BP and is reflected by the domination of polyhalobous diatoms, increasing mean grain size, biogenic silica, and calcium and magnesium contents. The Initial Littorina Sea was a 1500-year-long period in Mecklenburg Bay, existing until the Littorina transgression. The main Littorina transgression first appeared in Mecklenburg Bay around 7700 cal BP and after a few hundred years at around 7200 cal BP in the Arkona Basin.

“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.

X-ray fluorescence (XRF) core scanning has become widely available for geological studies during the last decade. The data obtained from XRF core scanning, however, may be strongly influenced by the amount of organic matter, water content, density and porosity of the sediment matrix. In this study we discuss the usefulness of XRF core scanning to distinguish different kinds of organic-rich sediments and peat based on examples from tropical Lakes Kumphawapi and Nong Leng Sai in Thailand. We examined how sedimentary factors influence XRF core scanning analyses by comparing elemental and scattering ratios to lithological changes and quantitative LOI, TOC, biogenic silica (BSi) and grain-size values. Our comparison suggests that the (inc/coh) scattering ratio is of limited use as an indicator for variations in LOI and TOC in peaty gyttja or peat. In Lake Kumphawapi's sediments, Si/Ti ratios reflect clastic input associated with grain-size variations rather than BSi contents. The Ti-normalized ratios of Si, Zr, Sr, K and Rb are linked to mineral input and associated grain-size variations. We conclude that XRF core scanning of organic-rich tropical lake sediments and peat is useful to infer palaeoenvironmental conditions. However, XRF core scanning data does not stand-alone and needs to be underpinned by additional proxies.

This study presents the results and interpretations of biological (floral and faunal) and geochemical (isotopic and chemical element composition) investigations of the Late Glacial and Holocene sediment accumulated in the Kaniewo palaeolake. These data allowed us to determine the indicators of environmental changes in this lake ecosystem, such as zooplankton and vegetation development, trophic state, water temperature, and water level. We documented the three cold periods (Oldest, Older, and Younger Dryas) separated by two warm periods (Bolling, Allerod). Additionally, we found traces of cold oscillations within the Allerod, lasting approximately 150 years, probably the Intra-Allerod-Gerzensee oscillation, recorded in western and southern Europe. Our data show that sediment accumulation began at the end of the Oldest Dryas period before ca. 13,900 yr cal BP. The top of the studied sediments represented the transition from the Late Glacial to the early Holocene (Preboreal period, ca.10,500 yr cal BP). The lithology of the sediments changed from silty sands at the bottom, then calcareous detritus gyttja partially interbedded by lake marl to peat at the top. Organic matter occurring in the deposits reflects algae and terrestrial sources. In the cold periods, small number of both Cladocera individuals and species (e.g. Bosmina (E.) longispina, Chydorus sphaericus, Alona affinis), corroborate the unfavourable conditions for the development of zooplankton. Cladocera species indicated the initial oligotrophic status of the lake and the subsequent increase in trophic status. Plant and animal macrofossils indicate initial shallow lake ecosystem. Chara meadow developed at the bottom of the lake with a belt of vascular plants (Carex sp., Hippuris vulgaris, Scirpus sp.) in the littoral zone of the lake. Rich shallow vegetation was accompanied by animals, such as Mollusca (e.g. Valvata piscinalis, Pisidium obtusale, Bithynia tentaculata) and Oribatidae sp., Cristatella mucedo, and Plumatella type.

This study presents a multi-proxy reconstruction of the evolution of Smolak Lake from harmonic to dystrophic conditions. The lake’s history and environmental conditions, such as zooplankton and vegetation compositions, trophic state, water temperature and water level fluctuations, are discussed. Smolak Lake is located in the southern part of the Masurian Lakeland, northern Poland. A 350 cm core comprising thick sediments (Sm profile) are mainly composed of homogenous organic gyttja and dy was taken from the lake and analysed for geochemical and biological (cladoceran and pollen) proxies. Radiocarbon data show that the sediments accumulated from the Late Glacial (Younger Dryas period) to recent times. Based on the results of pollen data, six local pollen assemblage zones were recognized. The subfossil cladoceran fauna in the sediments are represented by 25 species belonging to four families. Five zones of Cladocera development were distinguished. The Cladocera species indicate the initial oligotrophic status of the lake and its subsequent slight increase in trophic status. From ~9000 yr cal BP (at the beginning of the Atlantic period), Smolak Lake began a fast transition to a dystrophic state. At this time, the amount of total organic carbon (TOC) in the sediments significantly increased to above 50%, and deposits containing more than 97% water were transformed into dy. The sedimentation rate was extremely low, i.e., 0.08–0.2 mm/yr. Dystrophic conditions are also reflected in the Cladocera and pollen found in the core during this period: Cladocera composition was dominated by species very resistant to acid conditions (e.g., Alonella excisa); the abundance of green algae was at its lowest level and dominated by only one genus (Botryococcus); no hydrophytes were found; and rush vegetation disappeared. Currently, Smolak Lake is a shallow, humic lake characterized by brown water and the presence of floating mats. This study shows that it’s current status is a result of it’s small, relatively undisturbed catchment, which should be protected in order to maintain this unique dystrophic habitat.

The results of lithological analysis, diatom analysis and radiocarbon dating of bottom sediments from the basin of a lake located at an elevation of 17 m above sea level near the Teriberka settlement (Barents Sea coast, Kola Peninsula) are presented. The stages of the lake evolution were revealed based on a comprehensive investigation of its bottom sediments. The lake basin was covered by sea at the end of the Pleistocene. The lake became isolated from the sea approximately 11500 cal. yrs BP, but was re-filled with sea water after 10400 cal. yrs BP due to the Tapes transgression. In lower part of the Tapes sediments, there is a disturbance of the sediment sequence, represented by a mixture of sand, gyttja and plant residues. According to radiocarbon dates, this disturbed hori­zon was deposited between 10400 and 8200 cal. yrs BP. An abrupt increase in the con­tent of marine diatoms was found in this horizon. The disturbed sediments have possibly formed as a result of the Storegga tsunami. When the horizon of tsunamigenic sediments was forming, the sea level was slightly above the threshold for discharge from the lake (ca. 18 m above modern sea level). The second local event (tsunami?) occurred after 8220 cal. yrs BP, when the coastline was already below the lake threshold. As a result of this event, an interlayer of sandy sediments formed in the bottom sediments within gyttja.

Small-sized ferruginous micronodules or pisolith nodules, frequently occurring in inland freshwater systems in moderate climate zones, are important indicators of groundwater level changes and early diagenetic processes, especially within the Pleistocene post-glacial sedimentary systems, including swamps, peatbogs, rivers, or lakes. Compared to the other geochemical environments, pisolith nodules are usually dominated by iron hydroxides and oxides. In most cases, described micronodules indicate high phosphatization, significant contribution of allogenic detrital components, and low manganese content. The major aim of the article is to present textural, geochemical, and mineralogical variability of pisolith nodules recovered from the Roztoka Odrzańska, Odra river mouth area, NW Poland. We describe genetical relations between different types of pisoliths and try to interpret the possible formation phenomena. Analyzed loose ferruginous micronodules were separated from the lacustrine silty-clayey sapropel muds and gyttja, later analyzed using optical microscopy, SEM-energy dispersive x-ray (EDX), and XRD methods. As a reference material, we use archival iron bog ores and geochemical data of different types of nodules. Additionally, we describe previously unknown siderite-rich nodules found in neighboring sites of the Dąbie Lake and the Szczecin Lagoon.

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.

This paper presents the results of an assessment of macro- and microelements in the sediments of lakes laying within protected areas in Poland – the Drawa National Park, the Wel Landscape Park and the Górzno-Lidzbark Landscape Park. In each lake two grab sediment sample were collected: one in the littoral zone and the other in the deepest part of the lake basin. Sediment samples analysed for their content of inorganic carbon (IC) and the loss on ignition (LOI at 550°C) and, according to these parameters classified into three sediment types. Micro elements were detected with SEM-EDX system and the bioavailability of Zn, Cu, and Fe was evaluated after an extraction with DTPA (diethylenetriaminepentaacetic acid) solution. The most diverse chemical composition of the sediments was observed in the lakes of the Wel Landscape Park Lacustrine sediments were characterized by the heterogeneous content of organic matter (from 11.70 to 52.89%), calcium carbonate (from 0.0 to 42.73%) and mineral fractions (from 38.24 to 79.46%). They consisted of three different types of gyttja (fine grain-size, clayey-calcareous, clayey). The highest content of trace elements was determined in fine grain-size gyttja, which results from their current sorption properties, as well as alimentation by river waters flowing into the lakes. The sediments contained relatively low concentrations of the analysed elements, which was reflected in the low values of the contamination factor (CF), the contamination degree (Cdeg), the geo-accumulation index (Igeo) and the enrichment factor (EF). Values of the Igeo point out also that these lake sediments were not contaminated by heavy metals. The total content of zinc and copper in some analyzed sediments was higher than the content assumed as acceptable for protected areas. The contribution of bioavailable forms of Zn and Cu ranges from 2.3 to 29.1% for Zn, and from 4.6 to 18.4% for Cu. The type of sediment, and the surface area largely determined the lake sediment chemical composition, while land-use in the catchments had a minor effect. This applies to both lakes of different parks and lakes within each of the parks.

This research is focused on a small kettle hole located within the Morąg moraines (Ilawa Lake District, NE Poland). The study objective was to determine the impact of palaeoenvironmental changes in sedimentation and properties of sediments filling the bottom of the kettle hole. Sedimentological, geochemical, and palaeobotanical studies enabled us to distinguish several development phases of the kettle hole, and cluster analysis performed on physicochemical data yielded seven local geochemical zones (Ju I/I to Ju I/VII ). The beginning of biogenic sedimentation in the conditions of a small water body, functioning in the Late Glacial period (4.20–4.10 m), was determined on the basis of palaeobotanical research. Sediments deposited in the lake during its further evolution were rich in microelements such as Ca, Na, Mg, and K, and to a smaller extent – Fe and Mn (Ju I/I–III local geochemical zones). The Late Glacial lacustrine period ended with the accumulation of very silty, pollen-free gyttja, with a stratigraphic hiatus (Ju I/IV , 3.40–3.20 m). The sediments were enriched with SiO2ter, which indicates an increased rate of slope erosion, and concretions of Fe-Mn occurring below this layer (Ju III ) provide evidence for lowering of the water level and even desiccation. In the Holocene, the lacustrine period ended with the accumulation of coarse detrital gyttja (3.20–2.60 m). Palaeobotanical data indicate that the next group of sediments were deposited in the Late Subboreal and Subatlantic periods (2.60–0.0 cm, Ju I/V–VII ; sedge peat). Their properties were varied and related to hydrologic conditions, limited denudation, and vegetation succession. There was also a significant change in the trophic conditions of the water and consequently in the sediments of the kettle hole, which changed during the lacustrine period from basic to acid, and strongly acid in the surface layer. This reaction may be related to a change in the water regime as well as to human impact in the environment, which led to the colonization of the peat bog by Sphagnum moss.

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