TY - JOUR

T1 - Saline lakes of Northern Kazakhstan: Geochemical correlations of elements and controls on their accumulation in water and bottom sediments

AU - Kolpakova, M. N.

AU - Gaskova, O. L.

AU - Naymushina, O. S.

AU - Karpov, A. V.

AU - Vladimirov, A. G.

AU - Krivonogov, S. K.

N1 - Publisher Copyright: © 2019

PY - 2019/8/1

Y1 - 2019/8/1

N2 - This paper is a review of the saline endorheic lakes of the Northern Kazakhstan, with the provided data on chemical composition of their waters and sediments, diversity/uniformity, mineral precipitation sequences and brine evolution. Study saline lakes are located in the Ishim steppe geographical unit of the southern Western Siberia and are ancient closed basins. The lakes are of Cl–Na and Cl–Na–Mg chemical types (the most saline Zhalauly lake (428 g/L) is Cl–Mg type), their pH values vary from 6.0 (Kalibek lake) to 9.1 (Shureksor Lake). The common trend for the lakes chemical state is a low calcium concentration with high values of sodium, i.e. calcium < magnesium < sodium (with three exceptions). The Na/Cl, Cl/SO4 and Mg/Ca ratios were calculated for the solutions from the lakes in order to reveal their primary trends of geochemical evolution. The geochemical indexes of enrichment and pollution (EF and Igeo) of the bottom sediments show that enrichment is low or absent in comparison with the geochemical background for the lakes of Western Siberia. We imply four main stages of lake evolution indicated by precipitation of different secondary minerals: calcite and Mg-carbonates, gypsum, halite, thenardite and bischofite. We suggest the onset of crystallization of each mineral as a tipping point of the water evolution that resulted in the complete removal of a certain chemical element consistent with the solubility constant of corresponding mineral.

AB - This paper is a review of the saline endorheic lakes of the Northern Kazakhstan, with the provided data on chemical composition of their waters and sediments, diversity/uniformity, mineral precipitation sequences and brine evolution. Study saline lakes are located in the Ishim steppe geographical unit of the southern Western Siberia and are ancient closed basins. The lakes are of Cl–Na and Cl–Na–Mg chemical types (the most saline Zhalauly lake (428 g/L) is Cl–Mg type), their pH values vary from 6.0 (Kalibek lake) to 9.1 (Shureksor Lake). The common trend for the lakes chemical state is a low calcium concentration with high values of sodium, i.e. calcium < magnesium < sodium (with three exceptions). The Na/Cl, Cl/SO4 and Mg/Ca ratios were calculated for the solutions from the lakes in order to reveal their primary trends of geochemical evolution. The geochemical indexes of enrichment and pollution (EF and Igeo) of the bottom sediments show that enrichment is low or absent in comparison with the geochemical background for the lakes of Western Siberia. We imply four main stages of lake evolution indicated by precipitation of different secondary minerals: calcite and Mg-carbonates, gypsum, halite, thenardite and bischofite. We suggest the onset of crystallization of each mineral as a tipping point of the water evolution that resulted in the complete removal of a certain chemical element consistent with the solubility constant of corresponding mineral.

KW - Chemival evolution

KW - Hydrochemistry

KW - Northern Kazakhstan

KW - Numerical modelling

KW - Salinization

KW - Salt lake

KW - AQUEOUS-SOLUTIONS

KW - HEAVY-METALS

KW - CONTAMINATION

KW - SULFUR

KW - SURFACE-WATER

KW - TRANSPORT

KW - EVOLUTION

KW - POLLUTION

KW - ENRICHMENT

KW - CHLORIDE

UR - http://www.scopus.com/inward/record.url?scp=85066253196&partnerID=8YFLogxK

U2 - 10.1016/j.apgeochem.2019.05.013

DO - 10.1016/j.apgeochem.2019.05.013

M3 - Article

AN - SCOPUS:85066253196

VL - 107

SP - 8

EP - 18

JO - Applied Geochemistry

JF - Applied Geochemistry

SN - 0883-2927

ER -