Recent patterns of sediment accumulation in a small closed eutrophic lake revealed by the sediment records

A short-core palaeolimnological investigation was undertaken with the aim of acquiring knowledge of sediment deposition. Analyses of the lithological composition of sediments from the whole-lake basin were performed on the small eutrophic L. Linajarv ( northern Estonia) and the concentrations of mineral and organic matter were measured on 647 sub-samples from 14 sediment cores. The accumulation rate of the sediment sequences was established and C/N ratios of organic matter in some cores were recorded. Results indicate that the water depth, basin slopes and distance to the shore have the most important impact on the physical sediment properties. It was shown that variations in the mineral matter concentrations were influenced by the changes in deposition conditions in the areas with steep slopes. The study indicated that more objective information about the sedimentation mechanisms is obtained using analysis of the concentration ratio of mineral and organic matter since it reduces the implied role of diagenetic compaction.