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The mercury content in peat layers of seven peat bogs in the Małopolska region (Wolbrom in the Kraków-Częstochowa Upland and Otrębowskie Brzegi, Puścizna Wysoka, Puścizna Mała, Przybojec, Puścizna Długopole and Bór na Czerwonem in the Orawa-Nowy Targ Basin) was determined to a depth of 100 cm at a resolution of 1–2 cm. Geochemical background and level of anthropogenic mercury enrichment were determined for each peat bog. To establish the interdependence between mercury concentration, mineral matter content and selected metals, geochemical diagrams and models of the system were drawn up representing the correlational relationships between the selected geochemical variables for three of the peat bogs in the Orawa--Nowy Targ Basin (Otrębowskie Brzegi, Przybojec and Bór na Czerwonem). It was found that, comparing against other European raised bogs, the range of mercury concentrations in the peat layer down to 50 cm in the peatlands of Małopolska is similar to those in Norway, Sweden, Denmark and Spain, and decidedly lower than in the peatlands in Scotland, Belgium and Czechia. Furthermore, the sites in the Orawa-Nowy Targ Basin were clearly lower, the lower the altitude of the peat bog surface, which is probably associated with local topoclimatic conditions. [ABSTRACT FROM AUTHOR]

The subject of the work is a reconstruction of environmental conditions in the Lower Oder River Valley in the early Middle Ages with use multi-proxy research. This was considered in terms of natural determinants of the development of hydrogenic habitats in the estuary section of a large lowland river, but at the beginning of a headland of natural morainic plateau known as Castle Hill in Szczecin. In a relatively small area, three different types of geochemical landscapes were distinguished that had specific functions in matter cycles, including the water cycle. The article mainly presents the results of geochemical studies for a series of biogenic deposits separated by a series of lacustrine sediments with a large admixture of mineral material. An attempt was also made to determine subfossil animal remains in the sediments. [ABSTRACT FROM AUTHOR]

The sedimentary succession exposed in the Gorzów Wielkopolski area includes Eemian Interglacial (MIS 5e) or Early Weichselian (MIS 5d–e) deposits. The sedimentary sequence has been the object of intense interdisciplinary study, which has resulted in the identification of at least two palaeolake horizons. Both yielded fossil remains of large mammals, alongside pollen and plant macrofossils. All these proxies have been used to reconstruct the environmental conditions prevailing at the time of deposition, as well as to define the geological context and the biochronological position of the fauna. Optically stimulated luminescence dating of the glaciofluvial layers of the GS3 succession to 123.6 ± 10.1 (below the lower palaeolake) and 72.0 ± 5.2 ka (above the upper palaeolake) indicate that the site formed during the Middle–Late Pleistocene (MIS 6 – MIS 5). Radiocarbon‐dating of the lacustrine organic matter revealed a tight cluster of Middle Pleniglacial Period (MIS 3) ages in the range of ~41–32 ka cal bp (Hengelo – Denekamp Interstadials). Holocene organic layers have also been found, with 14C ages within a range of 4330–4280 cal bp (Neolithic). Pollen and plant macrofossil records, together with sedimentological and geochemical data, confirm the dating to the Eemian Interglacial. [ABSTRACT FROM AUTHOR]

We use a range of environmental variables to explore the possible drivers influencing the biota, especially the composition of aquatic invertebrates, during the Younger Dryas (YD) and Early Holocene (EH) in different river valley sites: a well-developed meandering river and the confluence zone of headwater streams. Using pollen, macrofossil, cladoceran, and chironomid as well as geochemical and lithological data as proxies for environmental factors (i.e., water depth and temperature), we attempt to show that these different sites display similar hydroclimatic signals (especially floods). The geochemical records in the studied valley are correlated with environmental factors, such as the evolution of the vegetation, the intensification phase of slope processes, and fluvial activities. Cladocerans and chironomids potentially play important roles in the recognition of flood episodes in the study sites, and any shift in their diversity and, especially, the co-occurrence of planktonic, sediment-associated cladocerans with rheophilic chironomids could be valuable indicators of floods and flow episodes. The variable changes in water levels at the sites reconstructed by the cladoceran-based water-depth model were positively associated with changes in lithophilic elements (K, Na, Al, Mg, and Ti), SiO 2(biog + ter) and Fe/Mn, and our estimates of the paleohydraulic parameters for the study sites are generally consistent with changes in the composition of aquatic invertebrates. The recorded YD floods appear to be synchronous, regardless of the size and the different geological and geomorphological settings of each part of the river catchment. Our investigation demonstrates that flood magnitude increases in the downstream direction along the valley. The common increases in the water level at all study sites from the Grabia River valley are significant from 12,400 to 12,200 and from 11,900 to 11,800 cal BP and are comparable with those from elsewhere in Poland and Europe. [ABSTRACT FROM AUTHOR]

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This paper presents a palaeoenvironmental reconstruction of the Wilczków fen (central Poland). The fen developed in an inactive valley at the onset of the Holocene (~11 ka BP) and peat accumulation lasted until 5.7 ka BP. Multi-proxy reconstructions were made on the basis of palaeobotanical, cladoceran, chironomid, beetle and geochemical analyses. A Kohonen self-organizing map ( SOM, unsupervised artificial neural network) of the biotic sequence distinguished four stages of fen history. Stage X1 (11.0-10.7 ka BP) was relatively wet and cool. Organic matter started to accumulate but the habitat conditions remained unstable. Moss, sedge and fern communities then developed. Sedimentary changes reveal an intensive groundwater supply at that time. Numerous and diverse chironomid and cladoceran subfossils indicate nearly permanent aquatic conditions. During stage Y1 (10.6-9.2 ka BP) conditions were dry and the upper peat layer desiccated. Cladocera nearly disappeared whereas chironomids were represented by semi-terrestrial and predatory (Tanypodinae) species. Conditions started to be more reducing. All the remaining samples belonged to the interweaving stages X2 and Y2. Stage Y2 (mostly 9.1-7.3 and 6.0-5.7 ka BP) was also dry but humidity increased towards the top. Oxidizing conditions occurred and the pH became more alkaline, favouring Cladium mariscus. The basin received mostly allochthonous matter input at that time. Stage X2 (mostly 6.8-6.1 ka BP) was humid and warm. The groundwater supply remained low but there was an increase in precipitation, changing local conditions to ombrotrophic. Species-rich chironomid and cladoceran communities were associated with temporary pools. Finally, conditions returned to those characteristic of stage Y2. The presented reconstruction documents long-term abiotic and biotic changes determined by water supply, including groundwater outflow, which have rarely been detected at a multi-proxy scale. We show that inactivated valley fens are sensitive to climate-driven hydrological fluctuations. Kohonen neural networks appear to be a promising method for analysing variability in multi-proxy data. [ABSTRACT FROM AUTHOR]

The chemical composition of organic deposits from the site Koźmin Las are the basis of reconstruction of environment conditions of the Warta River valley at the end of the Alleröd and in the Younger Dryas. Environmental archives presented in this study, comprise organic matter content, mineral matter content, calcium carbonate content, reaction and macro- (Na, K, Mg, Ca, Fe, Mn) and microelements (Cu, Zn and Pb). The sorption of metals by organic matter and hydrated iron oxides, clay minerals accumulation variability in depositional environment, water relations of the ecosystem and bioaccumulation of some elements are the factors determining the chemical composition of organic sediments in the Warta river valley. [ABSTRACT FROM AUTHOR]

• Chemistry of sediments of Yinggehai basin E slope is correlated to SL- change. • Statistical PCA analysis confirms the essence of chemical variability of sediments. • Largest differences in lithology occur in deltaic sediments near the Hainan island. • Strong seismic reflectors are associated with high content of shell and gravels. • Lithology & chemistry of sediments allow to distinguish prodelta and delta front. The study was aimed at elucidating relationships between lithological and geochemical characteristics of sediments as indicators of sea level changes during the Late Quaternary on the eastern slope of the Yinggehai-Song Hong basin. The focus was on sediments of the late Pleistocene paleodelta formed on the shelf off the Hainan Island. Examination of two cores revealed a significant lithological and geochemical variability of the sediments, particularly in the lower segments of the delta deposits, associated with the delta front (core LDW) and with the distal part of the prodelta (core ZBW). The upper segment of the deltaic sediments in core LDW most likely represents a delta plain formed under the prevalent trend of increasing sea level. On other hand the upper segment of the deltaic sediments in core ZBW should be regarded as associated with sediments of the proximal part of the prodelta, formed when the delta front was advancing and the sea level was first rising and then stabilised. Attention was paid to the relationship between lithological and geochemical features of the sediments and the seismic profiling records, particularly with respect to the paleodelta sediment series. An attempt was also made to link and correlate the sediment series with sea level changes. [ABSTRACT FROM AUTHOR]