The Post-Glacial development of Ranviken bay in Lake Immeln. III. Palaeolimnology

Abstract

The palaeolimnology of Ranviken bay is interpreted on the basis of chemical sediment analysis and diatom analysis. The results are compared with those of a previously presented investigation of the palaeolimnology of Lake Trummen (Digerfeldt 1972).

As described in the paper on Lake Trummen, a proceeding oligotrophication should be a characteristic feature of the Post-Glacial development of temperate lakes. The productivity of Ranviken bay shows, as indicated by the loss on ignition and the organic C per annual deposition, a slight but distinct decrease during the latest periods of Post-Glacial time. The low organic deposition and indicated low productivity during the oldest periods is in conflict with the assumed natural lake development. Some possible explanations are discussed.