Reevaluation of the Lake-Sediment Chronology in the Dead Sea Basin, Israel, Based on New ²³⁰Th/U dates

Abstract

The Dead Sea is surrounded by chemical and detrital sediments that were deposited in its larger precursor lakes, Lake Samra and Lake Lisan. The sedimentary history of these lakes was recon-structed by means of 230Th/234U ages of 30 samples, mostly of argonite laminae, from 8 columnar sections up to 110 km apart. The general validity of the ages was demonstrated by subjecting them to tests of internal isotopic consistency, agreement with stratigraphic order, and concordance with 14C ages. In the south, only the part of the Samra Formation older than 170,000 yr is exposed, while the aragonite-detritus rhythmites found in the central and northern region are generally younger than 120,000 yr. The Lisan Formation started accumulating about 63,000 yr B.P., with the clay and aragonite beds in the south-central area reflecting a rise in water level to at least −280 m. The upper part of the Lisan Formation, the aragonite-rich White Cliff Member, started accumulating about 36,000 yr B.P. The lake probably reached its highest level sometime after this, based on the ages of Lisan sediments preserved in the southernmost reaches of the basin.

Complex exposure histories of chert clasts in the late Pleistocene shorelines of Lake Lisan, southern Israel

“…The late Pleistocene high-stand age of Lake Lisan is constrained by previously published chronologies (Begin et al, 1985;Kaufman et al, 1992) which are supported by our OSL ages. The age assignments are consistent …”

Deformation at a strike-slip, stepover zone along the southeastern margin of the Dead Sea pullapart basin, Jordan

“…Unconformably overlying the Paleozoic and Mesozoic bedrock are tilted Pleistocene fluvial gravels. These conglomerates may correlate to the Samra Formation (350 to 116 ka; Kaufman et al, 1992). The contact of the flat-lying Late Pleistocene lacustrine deposits of the Lisan Formation with the older units forms both buttress and angular unconformities.…”

“…The study area is located at the margin of the Lake Lisan which covered a large area of the Dead Sea rift during the Late Quaternary, ca. 63-15 ka (Kaufman et al, 1992). Base level lowering of the Wadi Araba drainage has been controlled by changes in the lake level of the Dead Sea and the Late Pleistocene precursor, Lake Lisan.…”

Stratigraphy, depositional environments and level reconstruction of the last interglacial Lake Samra in the Dead Sea basin

“…Sedom salt diapir, south of the Dead Sea. Other sedimentary units from the DSB were associated with the Samra Formation (e.g., Bentor and Vroman, 1960;Langozky, 1961;Sneh, 1982;Manspeizer, 1985;Kaufman et al, 1992;Weinberger et al, 2000); however, a complete sedimentary description of these deposits was lacking as well as their spatial correlation.…”