We examine the formation conditions for the resources and chemical composition of mineral lakes located in the vicinities to the unique natural site of the Barguzin intermontane depression, Nizhnii Kuitun. Presented are the results from studying the surface structure of this sand massif. It is shown that its formation is associated with peculiar features in the tectonic development of the Barguzin depression. It is pointed out that the block of rocks forming Nizhnii Kuitun is broken up by tectonic faults into several smaller parts, and this had a determining impact on its modern appearance. The lakes under study are situated in the northern part of Nizhnii Kuitun, in the Nukhe-Nur urochishche, in the topographically clearly pronounced drainless depression. The formation of this depression occurred during the uplifting stage of the block of rocks when intensively fragmented rocks, located at the interface of the faults, lagged behind in vertical movement. The depression receives the runoff of surface and underground waters which drain sedimentary deposits of Nizhnii Kuitun. Data are provided to demonstrate that the lakes are situated in the ablation funnels of sand-clay sediments. On the basis of a quantitative determination of the chemical composition of water and gases, it is proved that seepage waters of sandy sediments of Nizhnii Kuitun and nitrogenous fissure-vein waters play the main role in the formation of resources and chemical composition of the lake water in the area of the Nukhe-Nur urotshistshe. The hydrological-hydrogeological model of the formation of the lakes under study is suggested. In a dry period when the amount of water infiltrating through the sand deposits of Nizhnii Kuitun decreases, the proportion of deep fissure-vein waters increases; therefore, water mineralization increases in the lakes as well as fluorine, sodium, tungsten and molybdenum contents. In wet years, the contribution of drainage waters to the formation of the lake’s resources increases, and the concentration of these elements decreases.

Lake Gusinoe is the second largest freshwater lake in Transbaikalia. Lakes serve as a source for drinking water, irrigation, and as a water source for the electricity, aquatic production, and tourism industry. Currently variations of content nutrients and organic matter differ in different areas of the lake. The content of total nitrogen, phosphorus, organic matter, and dissolved oxygen are distinguished more than 1.2–2.0 times. In accordance with the behavior of elements in the water, three groups of elements can be distinguished. The first group of elements, including Li, Ga, Ge, As, Rb, Sr, Mo, Cd, W, and U, were directly correlated with variations of major elements. The first group of elements showed decreasing concentrations with an increasing amount of total dissolved salt (TDS). The second group of elements, including Fe, Y, Nb, Th, and REE, were correlated oppositely with variations of TDS. The behavior of the third group of elements, including Mn, Zn, Ni, Cu, and Pb, decoupled with TDS. The value of the Eu anomaly was positively correlated with TDS. The water of Lake Gusinoe was extremely enriched by W, Mo, V, U, Li, Sr, and Ga; moderately by Ni, Cu, Ge, As, Rb, Cd, and Pb; and minimally by Al, Cr, Mn, Fe, Co, Zn, Y, Th, and REE.

The effect of land-reclamation on the surface and subsurface runoff is studied in Ust’-Selenga depression has been analyzed. Drainage and irrigation activities intensified peat oxidation destruction, resulting in a more intense input of peat decomposition products (i.e., ammonium, nitrite and nitrate ions, as well as soluble organics). Surface and subsurface water draining the bog are favorable for the intense migration of iron and manganese ions in solution. These elements are found in concentrations exceeding the values of MAC for water bodies used for fishery.

Relevance. Negative impact of waste from mining enterprises on the ecological state of the surrounding areas. Aim. To determine the migration ability of toxic chemical elements from waste storage sites of the Ermakovskoe beryllium deposit in the air. Object. Ermakovskoe fluorite-bertrandite-phenacite deposit and the surrounding area. Methods. Inductively coupled plasma mass spectrometry, laser diffraction, inductively coupled plasma atomic emission spectrometry. Results and conclusions. The paper introduces the experimental studies of surface atmospheric pollution by mining waste from the Ermakovskoe fluorite-bertrandite-phenakite deposit are presented using an installation for collecting aerosols above the sand surface. It was established that toxic components formed during the decomposition of residual sulfide mineralization and products of the interaction of acidic waters with rocks move from the sand thickness to the surface along with water vapor. The moisture condensed over the sand contains high contents of aluminum, iron, manganese, zinc, and phosphorus. These elements form a halo of air pollution over mining waste and are then dispersed by air currents into the surrounding area. In winter, due to wind dispersion of aerosols, the snow cover becomes contaminated over a vast area. Among the toxic elements found were beryllium, lead, cadmium, and molybdenum, which belong to the second hazard class. The solid residue of the snow cover contains a fine fraction of dust, the size of which is less than 10 microns. The halo of snow contamination with toxic chemical elements and dust extends several kilometers away from the disturbed lands.