Four lakes with annually laminated sediments were selected for high-resolution quantitative climate and environmental reconstruction along an W-E transect throughout northern Poland. This selection was based on seismic pre-site surveys, statistical evaluation of morphometric data and after inspection of short gravity cores from more than 70 lakes (fig. 1). The deepest point of each lake was choosen as a coring location (fig. 2).

Fig. 1. Location of surveyed lakes with the highest potential for occurrence of annually laminated sediments in northern-central and north-eastern Poland. Lakes cored in the framework of NORPOLAR are labelled in red. The site of Lake Gosciaz is marked for comparison.

Fig. 2. Bathymetric maps of the lakes selected. Coring sites are marked as black points.