Lake levels and sequence stratigraphy of Lake Lisan, the late Pleistocene precursor of the Dead Sea

Lake Lisan, the late Pleistocene precursor of the Dead Sea, existed from 70,000 to 15,000 yr B.P It evolved through frequent water-level fluctuations, which reflected the regional hydrological and climatic conditions. We determined the water level of the lake for the time interval similar to55,000-15,000 cal yr B.P by mapping offshore, nearshore, and fan-delta sediments; by application of sequence stratigraphy methods; and by dating with radiocarbon and U-series methods. During the studied time interval the lake-level fluctuated between similar to340 and 160 m below mean sea level (msl). Between 55,000 and 30,000 cal yr B.P the lake evolved through short-term fluctuations around 280-290 m below msl, punctuated (at 48,000-43,000 cal yr B.P) by a drop event to at least 340 m below msl. At similar to27,000 cal yr B.P the lake began to rise sharply, reaching its maximum elevation of about 164 m below msl between 26,000 and 23,000 cal yr B.P, then it began dropping and reached 300 m below msl at similar to15,000 cal yr B. P. During the Holocene the lake, corresponding to the present Dead Sea, stabilized at ca. 400 m below msl with minor fluctuations. The hypsometric curve of the basin indicates that large changes in lake area are expected at above 403 and 385 m below msl. At these elevations the lake level is buffered. Lake Lisan was always higher than 380 m below msl, indicating a significantly large water contribution to the basin. The long and repetitious periods of stabilization at 280-290 m below msl during Lake Lisan time indicate hydrological control combined with the existence of a physical sill at this elevation. Crossing this sill could not have been achieved without a dramatic increase in the total water input to the lake, as occurred during the fast and intense lake rise from similar to280 to 160 m below msl at similar to27,000 cal yr B.P (C) 2002 University of Washington.