Accumulation and fractionation of rare earth elements in surface waters of the Russian Far East under the conditions of natural and anthropogenic anomalies

The distribution and fractionation of rare earth elements were studied in surface waters from areas with different anthropogenic impacts in the southern part of the Russian Far East and in natural anomalous waters from areas with intense volcanic-hydrothermal activity. The levels of REE contents and their fractionation in the sequence from the light to heavy REE were estimated in different waters, and their connections with major ions and other trace elements, primarily Al, Fe, and Mn, were determined. The relations of the main forms of REE migration (dissolved and suspended) in surface waters were evaluated, and fundamental differences were detected in the accumulation of REE in the natural acid waters of the Kuril Islands and under continental conditions related to their deep input and redistribution in streams.     

Geochemical features of major and rare-earth element behavior in the Paratunka and Bol’shebannyi hydrothermal systems of Kamchatka

This paper presents original data on the content and distribution of major and rare-earth elements in the modern hydrothermal systems of the Paratunka and Bol’shebannyi thermal water deposits. In spite of the similar geochemical type of the waters, the individual sites of the hydrothermal systems differ in the major component composition, which is caused by the time of water–rock interaction, temperature control, and the possible influence of seawater intrusions. The REE concentrations in the studied thermal waters are extremely low (a few tenths of ppb). A distinctive feature of these thermal waters is the presence of a positive Eu anomaly. The possible reasons for its appearance are discussed. Calculation of REE speciation shows that the main parameters controlling the formation of the REE complexes in the Paratunka and Bol’shebannyi hydrothermal systems are their individual chemical properties, as well as pH, Eh, and temperature of the aqueous solution.     

Behavior of rare earth elements during mixing of different types of water (Kunashir,the Kurile Islands)

The fractionation of rare earth elements (REE) was evaluated under the conditions of natural acidic water mixing with fresh and sea waters using the example of unique objects on Kunashir Island (the Kislaya and Lesnaya rivers). It was shown that the concentrations and fractionation of REE in the water types considered are diverse and controlled by a number of factors. The concentrations of dissolved REE normalized to the North American Shale Composite show an increase from the light to the heavy REE, which reflects both the character of the REE input with the thermal waters and the more active sorption of the light REE and their preferential removal to suspended solids. This is supported by the similar REE patterns in the suspended matter of the Kislaya River. The mixing of the waters of the Kislaya and Lesnaya rivers, which are assigned to different chemical types, is accompanied by active REE coprecipitation with Fe, Al, and Mn oxides and the more extensive removal of the light REE compared with the heavy REE. During acidic water mixing with seawater, more than 80% of the REE were precipitated at a salinity of 8‰.     

Stanislav Romanovich Krainov

In Memoriam

Stanislav Romanovich Krainov     

Geochemistry of the thermal waters of Sikhote Alin

This paper reports new geochemical data on the low temperature nitric thermal waters of Sikhote Alin. The studied alkaline waters belong to the HCO₃-Na type with significant trace element variations. The waters demonstrate an increase in temperature and TDS from the south northward of Sikhote Alin. The oxygen and hydrogen isotopic data suggest their infiltration origin. The chemical composition of these waters was formed by water-rock interaction.     

Chemical and isotopic (<Superscript>18</Superscript>O/<Superscript>16</Superscript>O and D/<Superscript>1</Superscript>H) composition of groundwaters of central and southern Primorye

Groundwaters of Primorye, including its coastal areas, were studied during the past ten years. The macro-and microelement composition of more than 130 samples showed that shallow groundwaters of southern Primorye with pH ranging between 5.4 and 8.4 contain oxygen (up to 10 mg/l) and typically have a mixed ionic composition. The microelement variations reflect both the natural features of the host rocks and possible anthropogenic pollution in the most populated areas. No seawater intrusions were recognized in the study areas, which is confirmed by the chemical composition of the waters, the oxygen and hydrogen isotopic composition of the groundwaters, the atmospheric precipitation, and the coastal seawaters of Primorye. In spite of the variations of individual components, the quality of the groundwaters used for potable purposes is rather satisfactory as compared to the Russian and the World Health Organization standards. At the same time, taking into account the increase of various microelements and biogenic components in the waters, the monitoring and control of the water composition is strongly recommended to preserve their potable quality.     

REE geochemistry in groundwater of the Sikhote Alin fold region (Russian Far East)

Analysis of the distribution and fractionation of rare earth elements in the groundwater of the Sikhote Alin fold region reveals that their concentrations, geochemistry, and fractionation ability vary in different groundwater types depending on many factors, including the pH–Eh parameters and mineralization of the solutions and the composition of the host rocks. The results of monitoring of changes in the REE concentrations in the groundwater of the region over ten years provides the opportunity to establish the range of their variations. Inorganic forms of REE migration are rated for all geochemical types of water in the meteoric–surface–ground water system.     

Trace elements in surface water in Amur River basin

A wide range of trace elements contained in solution and suspension in surface waters in Amur River basin, which are subject to different anthropogenic load, has been considered. They have been found to vary widely because of their natural conditions, the impact of anthropogenic factors near cities (Khabarovsk, Komsomol’sk-on-Amur), and transboundary transport from the territory of China. Dissolved Mo, Br, and I are proposed as tracers of such transport.     

Chemistry of rainwaters in the south Pacific area of Russia

On the south-eastern edge of Russia, the chemical composition of rainwater is controlled by sea salts, terrestrial material, as well as volcanic (Kuril islands volcanic area) and anthropogenic emissions, mostly in the southern part of the area. The predominant major ions of the Primorye, Sakhalin and the Kuril Islands rainwaters were respectively HCO₃⁻–SO₄²⁻, Ca–Na, and of Cl–Na. Concentration of trace elements changes within 1–2 orders of magnitude but some difference in the distribution of the elements between continental and island rainwater is found. The concentration of the chemical elements in the particulate fraction varies from < 10% to 90% of the total concentration (dissolved + particulate) with the following distribution: Tl, Na, Ca, Sr, Zn, Cd (< 10%)–Be, Th, Bi, Rb, U, K, Sc (10–20%)–Cu, Mn, Mg, Mo, Se, Ba, Ni, As, Ag, Cs, Co, Y, Ga, V (20–50%)–Sb, Pb, Ge, Cr, Fe, Al (50–90%).The concentration of elements of the particulate fraction of the rainwater usually is significantly different from concentrations in the crust, including both higher and lower concentrations. The terrestrial contribution to dissolved elements was evaluated and follows the decreasing order: Fe > K, Mg, Ca > Ba, Sr > Na (65–1%). Close order was found for total (dissolved and solid) concentrations. Sea salt contribution to dissolved element concentration in the rainwater decrease in the following order: Cl, Mg > K, SO₄ > Ca > HCO₃⁻, Ba, Fe (78–0.1%). Calculation of anthropogenic and volcanic inputs for two ions (Cl⁻ and SO₄²⁻) shows that anthropogenic inputs for the Vladivostok and Yuzno-Sakhalinsk cities can be evaluated as 15–20% of Cl⁻ and up to 80–90% of SO₄²⁻. Volcanic components in the Kuril Islands, where anthropogenic inputs are absent, can reach up to 76% of SO₄²⁻ and 36% of Cl⁻.