The application of the Blytt and Sernander classification to the post-glacial sediment stratification in the lakes of the north-eastern region of Poland

Summary

In 1964, the author collected a sediment monolith from a depth of 4.10 m in the northern section of Great Lake Olecki in the Eastern Mazurian District (fig. 1).

The monolith was collected by means of a Hiller type chamber bore, the length of the chamber 0.5 m. The samples from the monolith were taken at intervals of 2.5–5 cm. The bed sediment structure was analysed; the absolute water content, organic matter and sedimentary chlorophyll contents were determined.

As a result of these investigations it was found that the thickness of the bed sediment i.e. from the surface of the present bed to the primary bed (post-glacial) consisted of 5.30 m at the site investigated. The structure was found to vary at the different depths (fig. 2A) and considerable fluctuations were noted in the quantitative relations of sedimentary chlorophyll (fig. 213), organic matter (fig. 2C) and absolute water content in the sediment (fig. 2D).

On the basis of the above analyses of the Lake Olecki bed sediment and of other lakes in the north-eastern region of Poland (Czeczuga, 1959, 1965) the author believes that these changes were brought about by climatic changes in that part of Poland during the post-glacial period.

These changes correspond to the changes given in the classification elaborated by the Scandinavian workers Blytt and Sernander (fig: 2E). In addition, the author distinguishes the neoboreal period between the subatlantic and the historical period; it was a period with a warm and dry climate.