Sedimentological record of Late Weichselian and Early Holocene in the Zbójenko kettle-hole in north-central Poland Mirosław T. Karasiewicz 1 , P. Hulisz 1 , A. M. Noryśkiewicz 2 , R. Stachowicz-Rybka 3 1) Institute of Geography, Faculty of Biology and Earth Sciences, Nicolaus Copernicus University, Toruń, Poland, mtkar@umk.pl , hulisz@umk.pl , 2) Institute of Archaeology, Faculty of History, Nicolaus Copernicus University, Toruń, Poland, anorys@uni.torun.pl , 3) Wladyslaw Szafer Institute of Botany, Polish Academy of Sciences, Kraków, Poland, ibrysta@ib-pan.krakow.pl In the south-east part of the Dobrzyńskie Lakeland in north-central Poland there are vast glacial basins the relief of which is dominated by drumlins. They are located in the hinterland of the maximum extent of the Kujawsko-Dobrzyńska Subphase, the Poznań Phase of the last glaciation (Weichselian) in Poland and within the so-called Chrostkowo snout morainic zone. In one of such basins in the vicinity of the village Zbójno there is a vast drumlin field, which was studied by Nechay (1927), Jewtuchowicz (1956), Niewiarowski et al. (1995), Olszewski (1997) and others. One of these authors paid attention to the fact that the drumlin forms are separated by kettle-holes filled with small water bodies. They have not yet been studied and that is why this paper aims at presenting mineral and biogenic sedimentation in one of them on the basis of interdisciplinary research methods. The study object was an intra-drumlin trough filled up with biogenic deposits (Zbójenko). The Więckowski probe was used for collecting undisturbed cores of the deposits down to the mineral bottom. The base for the biogenic deposits was grey glacial till. The cores of the 5.9 m thick biogenic deposits were used for palynological and macroremains analysis. Moreover, the contents of organic carbon (analyser CHN) and macroelements (ICP-MS) were determined together with the 14 C dating. In the roof of the profile, from 5.9 to 4.95 m, there was gyttia covered with high peat, mainly Sphagnum (Fig. 1), of diverse level of decomposition (H4 to H1 by the scale of von Post). The development of this type of peat is also observed nowadays. According to the palaeobotanic analyses the floor of the biogenic material (5.84 and 5.86 m) was deposited during the period of the arctic climate at the end of Old Dryas. The plant community was dominated by tundra with shrubs of sea-buckthorn (Hippophae rhamnoides), juniper (Juniperus), dwarf birch (Betula nana) and willow (Salix). Minimum July temperature for dwarf birch is 7ºC (Brinkkemper et al. 1987). After that the climate warmed (Bölling Interstadial), which initiated the advance of forest communities (5.30-5.80 m). At first these were open birch forests (Betula) with an admixture of Scots pine (Pinus sylvestris). Their development was halted during Younger Dryas (5.25- 4.90 m)., i.e. the final episode of Late Glacial. Cooler and dryer climate caused the forests to retreat and the tundra communities to develop. They included a large amount of juniper shrub (13%). When the water disappeared the lowering was invaded by trees (Betula sect. Albae, Pinus sylvestris). After a short episode of the development of fen the area in question was taken by a raised bog represented by Sphagnum. Continental climate and poor habitat at the dawn of Holocene (the Pre-Boreal Period) favoured the spread of pine-birch and pine forests (4.90-4.10 m). The plant taxa which then appeared showed larger climatic and habitat needs (Corylus avellana, Ulmus, Quercus). During the Boreal Period (4.10-3.70 m), when habitat condition significantly improved, hazel became common and gradually birch communities were displaced. Moreover, elm, oak and other thermophilous species advanced, including lime trees (Tilia) and common ash (Fraxinus excelsior). Waterlogged areas were overtaken by alder communities (Alnus). The results of physicochemical and chemical analyses of the deposits corresponded with the palaeobotanic data. In terms of the contents of the selected elements (organic C, Na, K,