Dedicated to Professor Dr Martin Schwarzbach, Koln on the occasion of his 70th birthday.
Holocene Carbonate Evolution in Lake Balaton (Hungary): A Response to Climate and Impact of Man†
- Albert Matter and
- Maurice E. Tucker
Published Online: 29 JUN 2009
Copyright © 1978 The International Association of Sedimentologists
Modern and Ancient Lake Sediments
How to Cite
Müller, G. and Wagner, F. (1978) Holocene Carbonate Evolution in Lake Balaton (Hungary): A Response to Climate and Impact of Man, in Modern and Ancient Lake Sediments (eds A. Matter and M. E. Tucker), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303698.ch4
- Published Online: 29 JUN 2009
- Published Print: 24 NOV 1978
Print ISBN: 9780632002344
Online ISBN: 9781444303698
- holocene carbonate evolution;
- precipitation of high-magnesian calcite;
- clastic material (quartz, feldspar, calcite, dolomite, phyllosilicates, heavy minerals);
- general increase of Mg/Ca ratio in the water of lake;
- lack of the ‘Rosa Zone’
Mineralogy, geochemistry and oxygen isotope composition of Lake Balaton carbonate sediments reflect fluctuations in the composition of the lake water, which were strongly influenced by both climate and man during the past 8000 years. During the ‘Pre-Roman Stage’ (about 7500–2000 y. B.P.) when the lake had no outflow (closed basin), calcite with low Mg, Sr and Na concentrations was precipitated at high water levels during periods with a relatively low rate of evaporation. High magnesian calcite with up to 20 mol per cent MgCO3 and elevated Sr and Na concentrations and protodolomite formed at low water levels during periods of high evaporation from solutions with higher Mg/Ca and Mg + Ca/Sr ratios and elevated Na concentration. These conclusions are also strongly supported by oxygen isotope data of the autochthonous carbonates. Lithium, associated with clay minerals correlates positively with Mg, Sr and Na.
In addition to the vertical fluctuations in carbonate composition within each core, pronounced lateral changes are found between the different cores: From core A (closest to the main inflow, the Zala River) to core F (farthest distance from the Zala River) the concentrations of Mg, Sr and Na incorporated in carbonates increase more or less steadily.
The interstitial waters in the cores show a similar development: The Mg/Ca ratios and the Na concentrations increase generally from core A to core F. Within each core the highest Mg/Ca ratios were found to occur in the lower half of the core where they are still close to the zone where the highest Mg concentrations of carbonate minerals are found.
Two periods with evaporation maxima can be traced along the long axis of the lake: one towards the end of the Atlanticum (about 5000 y. B.P.), another towards the end of the Subboreal (about 3000 y. B.P.). After an artificial outflow was built by the Romans about 2000 y. B.P., the lake changed from a closed to an open basin with only minor fluctuations in water level and hydrochemistry Since then, high magnesian calcite with a more or less constant rate of MgCO3−, Sr and Na incorporation has been precipitating during periods of algal blooms.