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Listvyanka settlement (Southern Baikal) was the first area to provide some evidences of ecological crisis on Lake Baikal. This is the most visited place on the lakeshore, with more than one million people coming to visit Listvyanka every year. However, there is practically no nature protection infrastructure in the settlement. Its ground waters are affected by anthropogenic influences to the largest extent. The electrical resistivity tomography method has revealed dimensions of the saturated groundwater flows coming from the littoral zone to discharge into the lake. The conducted integrated studies have revealed that chemical and microbiological pollution of the ground waters is higher versus that of the surface water flows, which shows an insignificant increase in the content of biogenic and potentially anthropogenic elements within a stretch from the outlet to the mouth. Subaquatic discharge of ground waters polluted by waste water from tourist infrastructure facilities occurs at depths of greater than 2 m, which is responsible for both ecological stress and catastrophic transformation of aquatic biocenosis in Lake Baikal.

The Pre-Baikal quartz-bearing province holding the second largest quartz resources amongst all known geological and commercial types of quartz deposits in the Russian Federation is of considerable scientific and practical interest for manufacturers of high-purity quartz concentrates. Quartzite deposits of the Gargansky terrain with the discovered ten occurrences of new non traditional high-purity raw quartz should be of primary concern. The Bural-Sardyk «superquartzite» and fine-grained quartzite display a number of favorable features distinguishing them from other geological-commercial types. Weakly-metamorphosed chemogenic-sedimentary quartzite-silicite regarded as an original rock for «superquartzite» and fine-grained quartzite appear highly promising in terms of expanding the mineral resource base. The unique chemical, technological and production properties of these rocks are of great value. Quartzite of the Gargansky terrain has a low initial content of chemical impurities whose concentrations decrease several times during the enrichment process, which ranks this quartz equal to such known products as IOTA-quartz, quartz of the Kyshtym Mining and Processing Plant and others. Basic mineral impurities for these types of raw material include micas for «superquartzite» and carbonates for quartzite-silicite which can be easily removed during the enrichment processes. Technological feasibility of this quartz type is underpinned by such components as a deposit size (hundred thousand tons of resources), close proximity to transport networks, stable qualitative characteristics of a useful component through the whole thickness of productive beds. Eastern Siberia possesses sufficient resources for quartz enrichment and concentrate production necessary to optical glassmaking, manufacturing of readily marketable quartz ceramics and solar power application.

The paper presents the results of a comprehensive study of silica glass produced from quartzite of the Bural-Sardyk deposit on its resistance to crystallization during thermal tests. A method for producing silica glass at a specially modified industrial plants for growing «REDMED10-M» and «REDMED 8» single-crystals is described. Melting of glass samples was performed in a vacuum and vacuum-compression method (with a pressure of up to 6 atm, argon). In order to evaluate the optical quality of the glass obtained from the absorption spectrum of the sample it was checked against the absorption of KI and KU-1 brand of glass. In the course of study, the glass obtained from chemically enriched quartz concentrates subjected to procedure a high-temperature exposure (cristobalite formation) was compared with that produced from quartz and concentrates not subjected to such a procedure. Thus, the objects of studies were glasses obtained from quartz concentrates of the four types: fine quartzite, cristobalite of fine quartzite, «superquartzite» and cristobalite of «superquartzite». A test procedure for resistance to crystallization of various types of silica glass samples is provided. The results of a comprehensive study based on X-ray phase analysis, and electronic and optical microscopy have shown that glass samples obtained from cristobalite grits of «superquartzite» are optically better and more resistant to crystallization than the samples obtained from «superquartzite» grits, fine quartzite and cristobalite of fine quartzite. Phase of cristobalite in glass samples occur at a temperature of 1150 °C in the spectra of X-ray diffraction. It is found that the crystallization of the quartz plates after annealing at 1200 °C during 2 hours is only on the surface.

Quartzites from Bural-Sardyk deposit are considered to be a source of high purity quartz raw material. The contents of fluid inclusions (FI) in quartzite is therefore an important technical characteristic. Fluid inclusions were studied in quartz grains of the most clean varieties of quartzites of the «productive series»: dark grey, grey and light grey fine-grained quartzites, and «superquartzites». The microcryothermometric parameters were measured using Linkam THMSG-600 thermal/freezing stage (Center for Isotopic-Geochemical Studies, IGC SB RAS, Irkutsk). The distribution of fluid inclusions in quartz grains is irregular. Cross fractures in quartz grains contain fluids, form band clusters with dense concentrations and narrow chains that intersect each other, extending in parallel or spaced apart. Two-phase fluid inclusions are observed at room temperature. Fluids that are flat tened, isometric, rounded and complex in shape are nor rare. The fluid inclusions differ in size in various types of quartzites, while the pattern of the distribution and phase composition are the same. It is practically impossible to measure microthermometric parameters in some fluid inclusions because of their minu te size (less than 8 microns). The temperature of ice melting was measured in fluid inclusions with a well-defined liquid phase. The analysis results showed that the salinity of fluid (from 5 to 9 wt.% NaCl-eq.) and its density increase from ultrapure «superquartz ites» to grey quartzites, with the FI sizes increasing in the same direction. It was established, that «superquartzites» are character ized by higher P-T-values of their formation conditions as compared to those of light gray and grey fine-grained quartzites.

The changes in the structural organization of a polymeric matrix of humic substances contained in therapeutic mud, coal and shale which take place in the process of their alkaline hydrolysis have been studied. These humic substances were isolated from some of the Mongolian deposits. Cumulative evidence on the composition and structural organization of humic substances provides a necessary base for creating new humic substances and medicines with enhanced levels of biological activity. The composition of ashy elements in initial and hydrolyzed humic substances of various types has been analyzed, and the results indicate that aluminosilicate present in the matrices belongs to sheet minerals and is identified by X-ray analysis as illite. The functional composition of humic substances has been thoroughly examined by IR and electronic spectroscopy. It is shown that during alkaline hydrolysis, the oxidation level of all samples increases by 15-25 %, and their water solubility exhibits multifold enhancement. Chromaticity coefficients of humic substances isolated from mud and coals increase more significantly after oxidative hydrolysis than those of shales. Functional groups of humic substances are freed from mineral components and become ionized in the alkaline medium. The morphology study of humic substances contained in medical mud, coal and shale has shown that they feature a layer structure with an uneven packing type of. It is noted that in the course of alkaline hydrolysis the morphology of the objects under study demonstrates a homotypic change towards a looser structure caused by reconfiguration of macromolecules. Varied effects of alkaline hydrolysis on the molecular structure of humic substances contained in therapeutic mud, coal and shale from Mongolian natural sources increases their reactivity.

The faulted structure of the crust, one of the components of the Earth’s geographical environment, has been studied in the vicinity of Ulaanbaatar, Mongolia. The study resulted in defining the positions of fault zones and nature of their activity at the recent stage of tectogenesis. The field of epicenters of earthquake events occurred in the area in the period from 2000 to 2014 was analyzed, along with the soil radon activity field forming near the faults distinctly featured in the relief. It is established that seismic activity and radon activity are closely related. Based on this conclusion, a network of 13 active fault zones was discriminated in the vicinity of Ulaanbaatar. They are divided into four systems that have generally inherited the neotectonic faults network, however, they differ in details of the inheritance. The NW and SE-trending fault zones develop along to the youngest faults, while the latitudinal and meridional zones are generally located across such faults. The fault zones of the orthogonal network are markedly distinguished by chains of maximums in the field of earthquake epicenters. This suggest strike-slip faulting in the conjugated planes of shear stresses. Reconstructions for the study area show the recent field of shear stresses with the SW-NE oriented compression axis and the SE-NW-oriented extension axis. This field is a remote result of the Indo-Asian collision and typical of the regions located southwest of Ulaanbaatar. In this paper, the faulting style is characterized as a principal factor that must be taken into account in the assessment of seismic hazard facing the capital of Mongolia which population is over a third of the country’s total population.

This study presents the data on first years (2013-2015) of the Boguchany reservoir structural formation, along with evolu tion of the dominant zooplankton community in its the upper portion. The study has been conducted at six stations located on the 130 km stretch in the lower reaches of the Angara River (downstream from the Ust-Ilimsk Dam). Given that both the com position and structure of zooplankton in Boguchany Reservoir, which closes the Angara cascade of hydropower stations (Dams), experience the influences from the Irkutsk, Bratsk and Ust-Ilimsk Reservoirs they appear in many ways similar to the fauna of rotifers and crustacea from these reservoirs located in the upstream part. Baikal Lake endemic Epischura baikalensis, and dominant species of the Irkutsk Reservoir from Notholса and Euchlanis ligulata genera have been detected in the upper portion of the studied reservoir. During first years of reservoir filling, the zooplankton diversity didn’t change, amounting to 28-30 spe cies. Its biomass and quantity is determined by the mass crustaceans typical for the Bratsk Reservoir: Cyclops kolensis, Daphnia galeata, Diaphanosoma brachyurum, and inhabitants of deep-water layers near the dam of the Ust-Ilimsk Reservoir: Cyclops abyssorum, Daphnia cristata, Daphnia longiremis, Heterocope appendiculata. As the Boguchany reservoir was filling with water, the river flow rates slowed down, and the temperature water decreased, while the depth of water increased, which created favor able environmental conditions for the limnofauna in the upper portion of the reservoir. For instance, in the third year (2015) of reservoir filling, when the reservoir water level reached the projected mark (208 m Baltic System), the quantity and biomass of the zooplankton had reached 57 600 specimen/m ³ and 1050 mg/m ³ , respectively, on the Edarma station located 100 km below the Ust-Ilimsk Dam, which is significantly higher than the levels observed in 2014 (13 000 specimen/m ³ and 165 mg/m ³ respec tively).

The investigation concerns with the faulting activity and strain conditions, which allows reconstructions of tectonic stress field for Northern Mongolia, comprising the Selenga, Orkhon and Tola River basins, in connection with the seismic hazard assessment of the area supposedly chosen for the construction of hydroelectric power stations. The study area is situated in the zone of dynamic influence of the eastern segment of the North Khangai strike-slip fault that splits into several branches whose distribution and distribution of stress state type depends on the location relative to major fault plane. The northeastern branch traced along the Selenga River valley is dominated by the left-lateral strike-slip and normal faults, where the extensional and transtensional, and shear tensors paragenetically related to them, were reconstructed. The southeastern sector shows the predominance of the NW right-lateral strike-slip faults, reverse faults and thrusts, and their corresponding shear, transpressional and compressional stress tensors were reconstructed. Within the southwestern sector we discovered the sublatitudinal left-lateral strike-slip faults and reverse faults, with the prevailing shear, transpressional and compressional stress tensors shown in the reconstructions. As a result, it has been found that within a 100-km radius from the power sites planned for future construction of dams on the Selenga, Orkhon and Tola rivers there are 3 to 6 faults with the evidence of the Holocene seismogenic activation. Therefore, the investigated system of faults in the area supposedly chosen for the construction of hydroelectric power stations in Northern Mongolia indicates potential seismic hazard that should be considered in their design and construction.

The results of research carried out in 2016 in winter and summer seasons, considering the current conditions of Listvy anka settlement and its surroundings, are represented. It has been established that geomorphological processes (landslides, earth flows, creep, erosion, debris flows of rare repeatability, and abrasion) are developing within the study area. The processes of peat formation and permafrost heaving are observed on the bottoms of creek valleys. The study of the vegetation showed that there is no irreversible degradation of forests in the settlement’s surroundings, and given that the area is not affected by wildfire the re growth of indigenous larch and conifer and pine forests will be possible. In the settlement and on roadsides, we found cultural garden plants incorporated into the local wild plant communities. The identified general patterns of present-day vegetation dis tribution evidence the domination of secondary communities in the forest vegetation. Results of the snow cover analysis showed minor changes in the acid-alkaline conditions. It was found that the snow cover in the village and in the lake basin contains NH4 ⁺ , Cl ^- , and PO4 ³ ions. The highest levels of particulates are observed in topmost parts of the valley. Hydrological studies and data of chemical water analysis showed the excess of ammonia nitrogen content (on 2-fold average versus the permissible limits adopted for Lake Baikal) in the water of the Krestovka River and Banny creek, where content of suspended solids exceeding the allowable values was also marked. Higher levels of particulates in surface waters are associated with seasonal high water stand (after rainfalls), with disturbed surfaces of watersheds, and due to transformations in watercourses channels.

The paper presents the data on specific characteristics of chemical pollution of air, soil and drinking water in rural and urban areas of the Irkutsk Region. These data were used as the underlying foundation for the «Information-analytical database: Assessment of the health and environmental situation and identification of high-risk zones in the Baikal Region». In urban areas, the dominant air contaminants are primarily benz(a)pyrene, formaldehyde, particulate matter, and nitrogen dioxide. The quality of potable water that fails to meet hygiene requirements is usually marked in rural settlements because of higher natural content of iron, manganese and anthropogenic pollution by nitrogen compounds. The content of chemical elements in the community soils does not exceed the maximum permissible concentrations. However, in the non-ferrous industrial zones there are areas of technogenic pollution where background levels of pollutants are significantly higher. Levels of aggregate risk to public health under the influence of chemicals polluting the environment (air, potable water, topsoil) have been calculated. It has been established that a significant contribution to the systemic toxicity is made by chemicals that people inhale. In the urban areas, the risk of exposure to systemic toxic effects of chemicals through inhalation ranks as very high. The pollution levels in the cities of Bratsk, Irkutsk, Usolye-Sibirskoye, and Shelekhov are found to be record high in terms of cumulative health risks. The aggregate risk in the rural areas of the region corresponds to the allowable level.