Abstract
A total of 409 sediment samples were collected from lake deeps of 260 lakes in the Greater Poland, Pomerania and Masuria Lakelands. All samples (fraction <0.2 mm) were analysed for the concentration of zinc (Zn), Al, Ca, Mg, Fe, K, Mn, Na, P, S and TOC. The Zn concentration in the lake sediments varied from <6 to 1006 mg/kg, the average concentration was 93 mg/kg and the geometric mean 74 mg/kg. In most of the samples, the Zn concentration was less than 200 mg/kg (except in 19 samples). The Zn concentration shows significant correlation with the contents of Al, K, S and Corg., and poor or no correlation with the contents of Mn, Na and Ca. Scatter plots show a clear relationship between the Zn content and the contents of Al and K, indicating that a significant part of Zn is associated in the sediments with clay minerals. There is also a correlation between the Zn content and the concentrations of Corg. and S, suggesting that a part of Zn is bound by organic matter. A relatively poor relationship between the Zn concentration and the concentrations of Fe and P has also been found, indicating that a part of Zn may also be associated with iron minerals. Factor analysis has shown that in lake sediments of the Masuria and Greater Poland Lakelands Zn is primarily bound by organic matter, whereas in lake sediments of the Pomeranian Lakeland by clay minerals.