Vol 55, No 1 (2017)

Two methods for obtaining information on the fractional composition of organic matter in natural waters (membrane filtration and oxythermography) are combined in this study. The method has a number of indisputable advantages, which distinguish it among the currently available methods of analytical chemistry. In earth science, the fractional composition of organic materials in natural waters is estimated by the concentration of organic carbon (C_org) in fractions. In our opinion, an indicator of chemical consumption of oxygen (CCO) for ecological estimation of water reservoir state is more informative, because this indicator carries specific ecological information on the necessary oxygen consumption for oxidation of pollutants coming into the natural water environment. Therefore, estimation of the CCO parameter in fractions provides real information on the availability of organic matter and the probable danger from its content in water. This is the principal novelty of the information obtained and our study. The method was tested in the study of variation of the fractional composition of water matter during passage of Volga water through the waterworks (upon removal of water from the storage reservoir through the dam of the Ivan’kovskaya hydro power plant in the Dubna area). Analogous results are almost absent in earth science literature. There is a lack of data on the influence of water release through the dam even with respect to the major-component chemical composition. Variation of the fractional composition of matter (both organic and inorganic) upon water release through a waterworks is not discussed in literature. Thus, this study is of fundamental character.

In this paper, we report experimental data on the implantation of hydrogen ions of different energies into crystalline quartz samples. It was shown that irradiation with protons with an energy of 20 keV produces an amorphous film on the surface of a quartz sample, and irradiation with 90-keV protons results in the formation of a layer with interstitial defects and an increase in the unit-cell parameter of quartz with preservation of the crystal structure of the disturbed layer. The examination of the samples by thermodesorption mass spectrometry showed that high-energy irradiation resulted also in loosening of the surface layer and considerable expansion of high-potential adsorption sites, which was the reason for the observed peak desorption of gases. The existence of desorption peaks allowed us to calculate the activation energy of surface desorption of gas components. It was also found that an increase in irradiation energy tends to enhance the total degassing of samples.

First systematic data on the variations of ε_Nd(T) in the Neoproterozoic sedimentary sequence of the Baikal–Patom fold belt (Northern Transbaikalia) are reported. The range of obtained εNd(T) is–19.4…–2.0. It was established that the rocks of the Ballaganach and most part of the Dal’nyaya Taiga groups are characterized by ε_Nd(T) from–19.4 to–16.3. Upsection, beginning from the Khomolkha Formation, the rocks show a sharp change in the initial Nd isotope composition (ε_Nd(T)–8.3…–2.0). The results of Sm-Nd study of metasedimentary rocks of the BPB, as well as the comparison of their Sm-Nd characteristics with those of the inferred source areas suggest that the input of terrigenous material at the early stage of sedimentation in the Baikal–Patom belt was mainly related to the destruction of the Early Proterozoic crust of the Siberian craton. Owing to a change of sedimentation setting from passive continental margin to the “foreland” basin at the late stage, the terrigenous material of the Siberian craton was diluted by clastics from juvenile Neoproterozoic crust of the Baikal–Muya belt.

Anthropogenically induced acidification of waters develops at humid territories in Russia. Acidified lakes with high water transparence, low pH (<6) and predominance of strong-acid anions make up 4.4% lakes in the European part of Russia and 8.2% in the tundra–taiga part of Western Siberia. The major factors responsible for water acidification are sulfur compounds emitted from smelters in the European part of Russia and synthesized when accompanying gas is combusted at oil-producing enterprises in Western Siberia. In combinations with natural factors, these processes result in complicated mechanisms of anthropogenic water acidification. Organic acids, whose concentrations in waters in humid zones are high, are able to enhance anthropogenic acidification.

Data were summarized on the speciation of the main platinum group elements (PGE) platinum, palladium, and rhodium in aqueous media, forms of their input into the environment, and mechanisms of accumulation by natural sorptive phases. In some cases, the results obtained for PGE were compared with those for gold. Data on PGE speciation in a number of natural environments were analyzed. It was found that the main factor controlling the migration ability of PGE (Pd > Pt»Rh) is the formation of stable compounds with dissolved organic matter, hydroxyl, and thiosulfate ions and nanometer-sized particles. The transport of dissolved PGE species by marine, riverine, and technogeneous suspended materials was evaluated as an alternative way of an increase in PGE mobility. Significant differences were revealed in the migration behavior of platinum, palladium, and rhodium indicating the dominance of palladium dissipation in a dissolved state. The possibility of the prediction of PGE accumulation and dissipation in technogeneous systems was demonstrated.

U-Pb age and isotope-geochemical features were determined for zircon from kyanite gneisses and amphibolites of the Chupa Sequence of the Belomorian mobile belt (BMB) of the Fennoscandian shield. The cores of the zircon from the gneisses marks the Neoarchean events within 2700–2800 Ma known in the BMB, while those of the amphibolites correspond to the age of magmatic crystallization (2775 ± 12 Ma). The inner rims of zircon from the amphibolites and gneisses likely record two different Neoarchean metamorphic events (2650 ± 8 and 2599 ± 10 Ma, respectively). The outer rims record Paleoproterozoic metamorphism with an age of 1890 Ma, which formed the modern appearance and mineral assemblages of the rock association. The value of δ18O in the zircon from the gneiss is 8.6‰ in cores, slightly decreases to 8.0‰ in inner rims, and sharply decreases to 3.9‰ in outer rims. The value of δ¹⁸O in the zircon from the amphibolite is around 6.2‰ in cores, increases up to 8.6 in inner rims, and decreases to 5.2‰ in outer rims. A significant decrease of δ¹⁸O is likely related to the anomalous composition of Svecofennian metamorphic fluid restricted to local shear zones. The geochemical features of the zircons in combination with their morphology and anatomy make it possible to distinguish zircon generations of different age and change in metamorphic environments.