SEARCH

SEARCH BY CITATION

Sediment core K10 from Lake Van (eastern Turkey) provides a continuous varve record back to 14,570 calendar years B.P. (before present, 1950), the longest unbroken and nonfloating lake varve sequence yet described. The underlying sediment is unvarved and hard. Changes in the aragonite/calcite ratio, the presence of protodolomite and magnesite in certain profile sections, the annual record of the sedimentation rate, the water content of the sediment, the concentrations of organic carbon and opal, and the texture of the sediments from this core provide a record of the lake level history. The new chronology enabled us to redate the old pollen profile [van Zeist and Woldring, 1978a, b] and to establish an accurate timescale for the reconstructed lake level change. Carbon 14 dates show that the highest lake terrace corresponds to high lake level at around 19,000 years B.P. during the Last Glacial, >70 m above its present level. Before 15,000 years B.P. the lake must have been completely dry, marking a reduction of lake level by 500 m in maximum 4000 years. Beginning at 14,600 years B.P. and ending at 12,040 years B.P., the lake level recovered by 250 m to fall again during the next 1400 years. By 10,600 years B.P. the lake began to rise and reached, following another regression between 9000 and 8100 years B.P., the Holocene highstand by about 7500 years B.P., dropping to today's level at about 3000 years B.P.