Distribution Profile of Chemical Elements during the Last 13 Thousand Years from the Sediments of Maloye Yarovoe Lake (Western Siberia, Russia)

Abstract

The article presents the studies on understanding the chemical evolution of Maloye Yarovoe lake that is located in the semi-arid landscape of and represent the most widespread chemical type of saline lake (Cl-Na) on the territory of Kulunda steppe (south of Western Siberia). The lake has gone through several changes in its state which are well represented in its sediments: section 1 (4.52–4.97 m) represents the subbase; section 2 (3.0–4.57 m) corresponds to a “shallow lake” stage and contains two sublayers; section 3 (0–2.25 m) illustrates an increase in erosion of the shoreline and corresponds to a “deep lake” stage. The extrapolation of radiocarbon dates suggests that the most significant changes in the state of the lake occurred at about 6.5–7.1 ka BP (transition from a small lake to a large one with intensified coastal erosion) and at about 5.69 and 3.5 ka BP (increase in the organic component). The results of sequential extraction of elements correspond to chemical changes occurred in a certain time of the lake state by changing in their distribution level and fraction type along the core. The results of lake water evaporation and organic matter degradation modelling performed in Phreeqc for oxic and anoxic condition showed the following stages of chemical divides could be expected in case of further lakes desiccation: Halite—Epsomite—Bischofite/Carnalite with possibility of Nahcolite precipitation in carbonate enriched periods (summer and autumn periods of organic matter degradation). Water–rock interaction processes in combination with biogeochemical reactions affect drastically not only the migration features of elements in water and sediments, but also the type of mineral crystallization in lake sediments.

Modification of Natural Peat for Removal of Copper Ions from Aqueous Solutions

“…Thermodynamic data are presented in Table 6. Further details have been provided in our previous studies [76][77][78]. Some of the parameters were determined experimentally, others were adopted from [59,79].…”

Water–Rock–Organic Matter Interactions in Wetland Ecosystem: Hydrogeochemical Investigation and Computer Modeling

“…It should be noted that the extremely high concentrations of zinc in the pore water of the D horizon are up to 10 ppm (10 times higher than the MAC). High zinc contamination of oligotrophic bogs of the Baraba forest steppe was also noted earlier [13,44]. Thus, the destruction of a number of minerals and the diagenesis of peaty vegetation residues leads to an increase in the concentrations of Al, Fe and P in the slightly acidic (pH 4-4.5) pore water of the upper part (horizon A).…”

“…Most scientific research is related to the study of the chemical composition of swamp waters and peat deposits, the mineralogical composition of the ash part of the sediments and the hydrological regime. Insufficient attention is paid to the study of complete Holocene sections of deposits, including the distribution of chemical elements [42][43][44][45].…”