Lithology of the long sediment record recovered by the ICDP Dead Sea Deep Drilling Project (DSDDP)

Abstract

The sedimentary sections that were deposited from the Holocene Dead Sea and its Pleistocene precursors are excellent archives of the climatic, environmental and seismic history of the Levant region. Yet, most of the previous work has been carried out on sequences of lacustrine sediments exposed at the margins of the present-day Dead Sea, which were deposited only when the lake surface level rose above these terraces (e.g. during the Last Glacial period) and typically are discontinuous due to major lake level variations in the past. Continuous sedimentation can only be expected in the deepest part of the basin and, therefore, a deep drilling has been accomplished in the northern basin of the Dead Sea during winter of 2010–2011 within the Dead Sea Deep Drilling Project (DSDDP) in the framework of the ICDP program. Approximately 720 m of sediment cores have been retrieved from two deep and several short boreholes. The longest profile (5017-1), revealed at a water depth of ∼300 m, reaches 455 m below the lake floor (blf, i.e. to ∼1175 m below global mean sea level) and comprises approximately the last 220–240 ka. The record covers the upper part of the Amora (penultimate glacial), the Last Interglacial Samra, the Last Glacial Lisan and the Holocene Ze'elim Formations and, therewith, two entire glacial–interglacial cycles. Thereby, for the first time, consecutive sediments deposited during the MIS 6/5, 5/4 and 2/1 transitions were recovered from the Dead Sea basin, which are not represented in sediments outcropping on the present-day lake shores. In this paper, we present essential lithological data including continuous magnetic susceptibility and geochemical scanning data and the basic stratigraphy including first chronological data of the long profile (5017-1) from the deep basin. The results presented here (a) focus on the correlation of the deep basin deposits with main on-shore stratigraphic units, thus providing a unique comprehensive stratigraphic framework for regional paleoenvironmental reconstruction, and (b) highlight the outstanding potential of the Dead Sea deep sedimentary archive to record hydrological changes during interglacial, glacial and transitional intervals.