Abstract
Results of complex investigations of sediments of the Błędowo Lake, located in the Wkra River valley, 100 km south of the maximum extent of the Vistulian Glaciation, are presented. The Błędowo Lake is the reference site of the IGCP 158 B project for the palaeoecological region of the Mazowsze-Podlasie Lowlands. A 15-meter long lake deposit profile, located in the central part of the lake, are representing a considerable part of the Late Glacial and the whole of the Holocene, as well as the Late-Glacial part of a second profile, located closer to the western bank of the lake, have been investigated. The pollen analysis, as well as the plant macrofossils analysis, have been carried out; nine local pollen zones have been distiguished. Diatom analysis (12 diatom phases), the analysis of Cladocera remains (10 phases of Cladocera development), and the geochemical analysis (11 geochemical zones) have been performed. The influence of the conditions of sedimentation upon the trace element redistribution has been determined. Combining the results of all the investigation, the history of the lake has been reconstructed, eight stages (A-H) of the lake development have ben distinguished, changes in the lake water level have been determined, sic stages of eutrophication - four of which being connected with human impact - have been distinguished.