A 45 kyr laminae record from the Dead Sea

• Verfasst von: Lu, Yin [VerfasserIn]
• Titel: A 45 kyr laminae record from the Dead Sea
• Titelzusatz: Implications for basin erosion and floods recurrence
• Verf.angabe: Yin Lu, Revital Bookman, Nicolas Waldmann, Shmuel Marco
• E-Jahr: 2020
• Jahr: 5 January 2020
• Umfang: 12 S.
• Fussnoten: Gesehen am 31.03.2020
• Titel Quelle: Enthalten in: Quaternary science reviews
• Ort Quelle: Amsterdam [u.a.] : Elsevier, 1982
• Jahr Quelle: 2020
• Band/Heft Quelle: 229(2020) Artikel-Nummer 106143, 12 Seiten
• ISSN Quelle: 0277-3791
• DOI: doi:10.1016/j.quascirev.2019.106143
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: Aragonite-detritus laminae
• Sach-SW: Basin erosion
• Sach-SW: Climate change
• Sach-SW: Dead Sea
• Sach-SW: Flash-floods
• Sach-SW: Magnitude-frequency
• Sach-SW: Paleolimnology
• Sach-SW: Transport-limited regime
• K10plus-PPN: 1693579022

Abstract

Recording and analyzing how climate change impacts flood recurrence, basin erosion, and sedimentation can improve our understanding of these systems. The aragonite-detritus laminae couplets comprising the lacustrine formations that were deposited in the Dead Sea are considered as faithful monitors of the freshwater supply to the lakes. We count a total of ∼5600 laminae couplets deposited in the last 45 kyr (MIS3-MIS1) at the Dead Sea center, which encompass the upper 142 m of the ICDP Core 5017-1. The present study shows that aragonite and detritus laminae are thinner and occur at high frequency during MIS 3-2, while they are much thicker and less frequent during MIS 1. By analyzing multiple climate-connected factors, we propose that significant lake-level drops, enhanced dust input, and low vegetative cover in the drainage basin during the last deglaciation (22-11.6 ka) have considerably increased erodible materials in the Dead Sea watershed. We find a decoupling existed between the significant lake-level drop/lake size reduction and lamina thickness change during the last deglaciation. We argue that during the Last Glacial and the Holocene, the variation of lamina thickness at the multiple-millennium scale was not controlled directly by the lake-level/size change. We interpret this decoupling implying the transport capacity of flash-floods is low and might be saturated by the oversupply of erodible materials, and indicating a transport-limited regime during the time period. We suggest the observed thickness and frequency distribution of aragonite-detritus laminae points to the high frequency of small-magnitude floods during the Last Glacial, in contrast to low frequency, but large-magnitude floods during the Holocene.