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The geochemical evolution of halite structures in hypersaline lakes: The Dead Sea, Israel
Author(s) -
Ganor Jiwchar,
Katz Amitai
Publication year - 1989
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1989.34.7.1214
Subject(s) - halite , brine , evaporite , geology , seawater , water column , salinity , geochemistry , mineralogy , hydrology (agriculture) , oceanography , structural basin , chemistry , geomorphology , sedimentary rock , geotechnical engineering , organic chemistry
Depressions in the floor of the southern basin of the Dead Sea contain dense (1.26–1.29 g cm −3 ) brines which formed by evaporation at the lake’s surface. Absorbance of solar radiation heats these brines by about 2.4°C d −1 , as long as the density gradient of the lake prevents overturn. As a result, bottom halite is dissolved in the warmer brines at about 0.4 g NaCl liter −1 °C −1 . Continuous heating of the brine of these holes and cooling of the overlying liquids at night causes frequent overturns of the brine column, followed by mixing and cooling of the NaCl‐rich brine. The extra load of halite is precipitated near the holes in the form of halite cones and mushroomlike structures. Whereas the initial NaCl supply to the growing halite structures comes from the floor of the lake, the later growth stage is supported by NaCl supplied from the upper (evaporating) brine layer. Crude mass and heat balances show that the proposed model may well explain the occurrence and distribution of halite islands in the Dead Sea. The model may be applicable to any shallow enough (a few meters) hypersaline lake that is saturated with respect to halite.