Limnetica 38

A high-resolution diatom record of the last 7500 years of Lake Balaton, a large, shallow calcareous lake in Central Europe is presented here. Diatom analyses were carried out on a 112 cm long core obtained from the Siófok Basin (eastern part of the lake) combined with loss-on-ignition, geochemical measurements and grain-size analysis. Altogether 140 diatom taxa were distinguished in this study; Amphora pediculus, Cocconeis neothumensis, Fragilaria brevistriata and Karayevia clevei were frequent and ubiquitous members of diatom assemblages. Fragilaroid taxa were dominant through the core in the shallow Lake Balaton, but episodes of higher ratios of planktic forms (Lindavia balatonis, Aulacoseira granulata and Pantocsekiella ocellata) before ca. 2000 cal yr BP, indicated high water level in the lake, and stronger fluctuation than exists today. The diatom-based reconstruction of lake level was in accordance with the geochemical and zoological records, proving the usability of siliceous remains in paleolimnological reconstructions in Lake Balaton, in spite of the unfavourable preservation conditions.