Variations of Oxygen Isotopes in the Hydrological System of Lake Holzmaar (Eifel, Germany): Implications for the palaeoclimatic interpretation of the sedimentary record

摘要

The ~(18)O behaviour of the hydrologic system of Lake Holzmaar, including the lake itself, a tributary, the outflow, a spring and precipitation, has been determined during two consecutive years. The seasonal cycle of the ~(18)O composition of the lake showed a variation of up to 2.1per thousand, which is mainly caused by evaporation. The pattern of the year to year variability was nearly identical for the two years under observation and is most likely characteristic for Lake Holzmaar under the present climatic conditions. If this pattern also holds for palaeohydrological conditions, a strong dependence of the delta~(18)O signal in the sediments of Lake Holzmaar on seasonality is to be expected.