Studia Quaternaria

In order to reconstruct environmental changes in the Borzechowo mire, a sediment core was subjected to macrofossil and stratigraphic analyses. The mire is located in the eastern part of the Pomeranian Lakeland (Tuchola Forest, northern Poland). It is a limnogenic mire, formed as a result of terrestrialisation of a water body. The time of basal peat accumulation was estimated by radiocarbon dating as 9860±130 14C BP (Gd-12393) and by palynological analysis as Preboreal. The analysis of macrofossils shows that in that period, considerable hydrological changes took place in the study area. These hydrological changes were caused by melting of dead ice blocks that was common place in the Late Glacial and the Early Holocene.

Fructification of Stratiotes aloides L. is very rarely recorded at present. In general, there are only one sex representatives in each lake basin, which simply makes generative reproduction difficult. The subfossil seeds of Stratiotes aloides have been found in five localities of biogenic accumulation in northern and central Poland.

Fennoscandinavian erratics found in the glacial deposits till and in the glaciofluvial sediments within the main limit of the Odra glacier lobe (NW Poland and NE Germany), have been examined in two fractions: of 4-10 mm and 2060 mm. The most numerous in the fraction of 4-10 mm are: crystalline rocks (Cr; 35-40%) originating in the Protero zoic Baltic Shield as well as Lower Palaeozoic limestones (LPL; 35-40%) - from the sedimentary sheet covering the Proterozoic Baltic Shield in the area of central Baltic Sea. Percentage of sandstones (S) amounts to 10-15%. The re maining rock types (several percent each) are: Palaeozoic shales (PS), the outcrops of which are localized in Scania (Skane) and on Bornholm, Cretaceous limestones (CL) and flintstones (F) originating from the western part of the southern Baltic Sea as well as quartz (Q), milk quartz (MQ) and isolated grains of Devonian dolomites (DD). From the analysis of indicator erratics, which was carried out in the 20-60 mm fraction, it appears that mainly the outcrops localized in Smaland (e.g. red and grey Viixjo granites, Paskallavik porphyries or Tessini and Kalmarsund sandstones) as well as in Scania (Hoor and Hardeberga sandstones) and Region Blekinge-Bornholm (e.g. Karlshamn and Halen granites as well as Nexo and Bavnodde sandstones) had been subjected to the glacial plucking. Theoretical boulder centres (TBC, German: TGZ das Theoretische Geschiebezentrum, Uittig 1958), which were calculated for 23 samples, are localized mostly in a small area in Smiiland, between 15°E-16°E and 56.5°N-58.5°N. Apart from indicator erratics the statistical ones are numerous, that are first of all grey and red Lower Palaeozoic limestones with their outcrops localized at the bottom of the central Baltic Sea. Taking into account the TBC values of indicator erratics as well as high percentage of statistical erratics it can be pronounced that the section of central and western Baltic Sea as well as the one of south-eastern Sweden had been subjected to the heaviest glacial plucking by that part of the Pleistocene ice-sheet which reached the studied area during the Pomeranian Phase.

This article presents results of the analysis of 3 sediment cores taken from the bottom of Pomeranian Bay, southern Baltic Sea. These results are part of a larger project that aims to determine the characteristics and rate of the Atlantic marine ingression in the Pomeranian Bay area. The main geochemical elements and diatom assemblages from the cores were identified, revealing lacustrine sediments deposited during the time of Ancylus Lake and marine sediments deposited during the Littorina transgression. Distinct changes in the geochemical composition and diatom assemblages suggest that the Littorina transgression had a very large impact on the environment of Pomeranian Bay.

The interglacial deposits at Zbójno near Radoszyce (central Poland) was drilled again and reinvestigated by means of pollen analysis. The pollen succession, partly recorded in subaerial sediments with many stratigraphic gaps, treated hitherto as the stratotype of Zbójnian interglacial, does not seem to differ from the Eemian sequence, and may actually be of the Eemian age. This strongly suggests that the term "Zbójno" should be removed from the Polish Pleistocene stratigraphy.

Analysis of weathering parameters of bones from cave deposits is presented as a useful tool of palaeoenvironmental reconstruction. As an example, we studied profiles of sediments in two Palaeolithic sites: Nietoperzowa Cave and Deszczowa Cave. Our studies included histological and EDS analyses of bone remnants found in these profiles. This method allowed us to reconstruct the changes of palaeotemperature and palaeohumidity, and finally the climatostratigraphy of sediments. The results presented here put a new light onto the stratigraphy of Deszczowa Cave's filling. In particular, besides the Vistulian sediments (MIS 2-5d), we confirmed the presence oflayers formed during the Penultimate Glaciation (MIS 6) and Eemian Interglacial (MIS 5e).

Bisnik Cave is an important site of Middle Palaeolithic, with the longest sequence of Neanderthal settlement phases in Central Europe. In the previous studies of the Bisnik sediments, different elements of palaeoenvironment in the periods of Neanderthal occupation have been recognised, except of palaeovegetation, which could not be derived because of lack of preserved plant micro- or macrofossils. The current work is an attempt to reconstruct palaeovegetation in vicinity of the Bisnik Cave, using analysis of composition of plant-derived n-alkanes, preserved in sediments. In our study, we analyzed one sample from each of the sediment's layers 11 - 19c (early Late Pleistocene and late Middle Pleistocene). Abundant n-alkanes (mostly n-C27, n-C29 and n-C31) were found in all the sampled layers except for the layers 12, 16 and 19d, showing no alkanes at all. There is clear diversification of n-alkanes composition and cpr (carbon preference index) values between layers. Analysis of this composition, allows us to claim that the layers 11 and 14 were accumulated when the cave's vicinity was covered by dense coniferous forests, hence upon warm climate. The layers 19, 19a lower, 19b and 19c, presumably originated during cold periods when open woodlands or grasslands dominated. The other analyzed layers could be counected with intermediate vegetation in form of open woodland. However, not all of the achieved results stay in compliance with the actual stratigraphy, established basing on lithological data and palaeoecology offossil fauna, and we hope that explanation of this discrepancy would be possible after more extensive studies of molecular fossils are done.