Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8907079 | Earth and Planetary Science Letters | 2018 | 11 Pages |
Abstract
The chemical composition and δ37Cl of pore fluids from the ICDP core drilled in the deepest floor of the terminal and hypersaline Dead Sea, and halites from the adjacent Mount Sedom salt diapir, are used to establish the dynamics of halite precipitation and dissolution during the last interglacial and glacial periods. Between â¼132 and 116 thousand years ago (ka) halites precipitated in the lake resulting in the expulsion of Na+ and Clâ from the residual solution. Over 50% of the Clâ reservoir was removed, resulting in a decrease in the Na/Cl ratio from 0.57 to 0.19. This process was accompanied by a decrease in δ37Cl values in the precipitating halites and the associated residual Clâ in the lake. The observed decrease fits a Rayleigh distillation curve with a fractionation factor of Î(NaCl-Dead Sea solution) = +0.32â° (±0.12) determined in the present study. This behavior implies negligible contribution of external sources of Clâ to the lake during the main peak of the last interglacial, MIS5e. Subsequently, during the last glacial (ca. 117 to 17 ka) dissolution of halite took place, the Na+ and Clâ inventory were replenished, accompanied by an increase in Na/Cl from 0.21 to 0.55 and in the δ37Cl values from â0.46â° to â0.12â°. While the lake underwent significant dilution during that time, the decrease in salinity was somewhat suppressed by the dissolution of the halite which was mostly derived from Mount Sedom salt diapir.
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Physical Sciences and Engineering
Earth and Planetary Sciences
Earth and Planetary Sciences (General)
Authors
Elan J. Levy, Yoseph Yechieli, Ittai Gavrieli, Boaz Lazar, Yael Kiro, Mordechai Stein, Orit Sivan,