Stratigraphic record reveals contrasting roles of overflows and underflows over glacial cycles in a hypersaline lake (Dead Sea)

Lu, Yin; Pope, Ed L.; Moernaut, Jasper; Bookman, Revital; Waldmann, Nicolas; Agnon, Amotz; Marco, Shmuel; Strasser, Michael

Abstract

In lakes and oceans, links between modern sediment density flow processes and deposits preserved in long-term geological records are poorly understood. Consequently, it is unclear whether, and if so how, long-term climate changes affect the magnitude/frequency of sediment density flows. One approach to answering this question is to analyze a comprehensive geological record that comprises deposits that can be reliably linked to modern sediment flow processes. To address this question, we investigated the unique ICDP Core 5017-1 from the Dead Sea (the largest and deepest hypersaline lake on the Earth) depocenter covering MIS 7-1. Based on an understanding of modern sediment density flow processes in the lake, we link homogeneous muds in the core to overflows (surface flood plumes, ρflow<ρwater), and link graded turbidites and debrites to underflows (ρflow>ρwater). Our dataset reveals (1) overflows are more prominent during interglacials, while underflows are more prominent during glacials; (2) orbital-scale climate changes affected the flow magnitude/frequency via changing salinity and density profile of lake brine, lake-level, and source materials.

Citation

Lu, Y., Pope, E. L., Moernaut, J., Bookman, R., Waldmann, N., Agnon, A., …Strasser, M. (2022). Stratigraphic record reveals contrasting roles of overflows and underflows over glacial cycles in a hypersaline lake (Dead Sea). Earth and Planetary Science Letters, 594, Article 117723. https://doi.org/10.1016/j.epsl.2022.117723

• Journal Article Type: Article
• Acceptance Date: Jul 7, 2022
• Online Publication Date: Jul 21, 2022
• Publication Date: Sep 15, 2022
• Deposit Date: Aug 17, 2022
• Publicly Available Date: Aug 17, 2022
• Journal: Earth and Planetary Science Letters
• Print ISSN: 0012-821X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 594
• Article Number: 117723
• DOI: https://doi.org/10.1016/j.epsl.2022.117723