The melting process and mechanism of the Antarctic ice sheet and its influence on the global sea level change are the major issues of global concern, and also the hot topic of the recent year dispute. The global warming theory elegantly accounts for sea level rise due to the CO₂ greenhouse effect as a consequence of human activities, by accelerating the deglaciation in Antarctica. However, observations show that subglacial water such as the Lake Vostok beneath Antarctic ice sheet as a consequence of basal melting is an important source of water contributing to the rise in sea levels. Besides, basal melting will reduce the buttressing of ice shelves, which may lead to glacier thinning, its acceleration and grounding line retreat. Here, we considered that the high heat flux of the rock under the ice cover may provide an explanation of global sea level rise by leading to the ice melting under the thermal heated ice sheet. We think that the volcanic action, the high heat flow rifting effect and other geothermal resources are most of the important causes of the basal ice melting. These recent findings of ice melting beneath Antarctica highlight the need for better understanding subglacial geothermal sources, their hydrologic interactions with marine margins, and their possible roles in global climate change.

The article deals with the geological-and-ecological state of the Vershino-Darasunsky settlement area, Trans-Baikal Territory, with the aim to define the degree of arsenic and heavy metal pollution of the above area and the former arsenic plant site. The analysis using certified methods has been conducted by the accredited laboratory of Irkutsk National Research and Technical University, the research objects being natural and technogenic objects of the former arsenic plant site. The paper presents the results of study on the arsenic and heavy metal content in the ruins of the plant structures, the site soil, and the cinder heaps. The study has shown that the arsenic and heavy metals content in all the samples is several hundred times the norm value. Based on the obtained monitoring data, a map of the arsenic content areal distribution for Vershino-Darasunsky settlement has been drawn. Besides, an aggregate index of soil pollution of the Vershino-Darasunsky are has been calculated. The index value is 553.61, which corresponds to the ‘extremely dangerous’ pollution category. In this connection, there is an urgent need for rehabilitation measures to eliminate the effect of the accumulated environmental damage caused to the natural-and-technological complex of the study area.

The study aims to demonstrate the capabilities of the modern aerogeophysical survey in prospecting for commercially promising copper-nickel mineralization objects of different types in the Far East of Russia. To realize the aim, innovation survey technologies and physical-geological models of mineralization are used. The set of geophysical methods includes a magnetic survey, gamma-ray spectrometry, and TEM sounding. The key feature of the above set is an electric survey technology that allows registering electrical inhomogeneities of several tens of meters at a depth of the first hundreds of meters. The survey has been conducted on a scale of 1:25 000, for an area of a complex geological structure with prevailing ancient (Archean) rocks. The extremely complex structure of the geophysical fields is a result of the long geological history with pronounced tectonic processes and diverse magmatism. For objective interpretation and localization of the explored objects, different methods of the statistical analysis of the geophysical data are applied, and quantitative interpretation of the magnetic and electrometric fields in the 1-3D format is performed. Based on the obtained aggregate information, volumetric geological mapping has been conducted (up to a 300 m depth), and ore objects of different types have been localized. Eight structure-substance complexes, including ore-bearing basic-ultrabasic and hyperbasic formations, have been distinguished in the study area. The above complexes form two large tectonic blocks with different metallogenic conditions due to the massive intrusion of the main composition, i.e. the source of copper-nickel mineralization. The faults form three systems with markedly different occurrence elements, i.e. pre-ore, syn-mineral (ore controlling) and post-ore. The area is characterized by widely developed mineralized zones of different genesis. Based on the specific geological and geophysical indicators, two ore-controlling complexes of copper-nickel mineralization have been distinguished, i.e. the first type (typical) and the second type (metasomatic). Based on the physical and geological models, ore objects per se have been localized, i.e. associations of ore-controlling formations with specific geophysical characteristics. In total, 12 promising sites have been localized, of which four have been defined as priority ones.

The purpose of the work is to compare the anomalous responses from the IP-effects in transient electromagnetic methods for galvanic and induction installations. By a galvanic installation is meant one using a horizontal electric line in a "line-line" configuration, and by an induction installation, one using ungrounded contours in a "loop-loop" configuration. Registering the fast decaying induction-induced polarization (IIP) that occurs in the geo-environment in the presence of polarized objects, makes it possible to avoid false electrical resistivity anomalies and to find polarizability anomalies. The comparison is realized using numerical modeling within the one-dimensional model with a frequency dispersion of electrical resistivity (described by the Cole-Cole formula). The modeling has shown that the anomalous IP-effect for the galvanic installation is higher than the IIP effect for the induction installation. The IP effect contribution virtually does not decay with time, as opposed to the IIP effect.

The purpose of the work is to study natural-mode polymetallic ore occurrences in the Altai Mountains using microinstallations (small-step measuring devices) for a qualitative evaluation of the ore bodies’ geoelectric characteristics. To evaluate the ore bodies’ geoelectric characteristics, the investigated medium was excited by a sequence of multidirectional current pulses in a generator dipole, and the electromagnetic field was registered by the receiving line by the technique of electromagnetic sounding and induced polarization. For the purposes of the medium modeling, an inversion of the non-stationary electromagnetic fields was applied within one-dimensional and tree-dimensional models with the account of the induced polarization effect. The zones with anomalous characteristics that were obtained with the one-dimensional inversion, correlate with the high silver- and copper-content zones defined by the means of the detailed geochemical sampling of the ditch. The three-dimensional modeling process used the following border conditions: the geometry of the ore bodies was set by the geological section, and their properties, by the one-dimensional inversion data. The polarization parameter anomalies obtained after several iterations have shown a spatial coincidence with the ore bodies position on the geological section. The relaxation time anomaly that is beyond the electrical survey profile corresponds to the known ore seam that had not been set in the initial approximation, which suggests a high sensitivity of the electromagnetic sounding and induced polarization technique to the polarization characteristics of the ore bodies. The study of the sulfide-mineralization ore bodies with the microinstallations provides information on the ore bodies’ polarization characteristics, spatial position, angle of incidence, and size. The suggested approach can be used in the geological-geophysical interpretation of the areal electromagnetic sounding data to define promising ore occurrences and optimize the prospect drilling and mining.

The article presents the study of the initial stress-strain state of the Yugo-Zapadnaya mine lower horizons, the Darasunsky gold deposit. The aim of the study has been to clarify the geotechnical conditions ensuring mining safety. A series of rock pressure monitoring stations have been installed, and in-situ measurements have been made using a slot discharge method based on the IGD UB RAS technique (segmented-slot version copyright). The rock samples taken at the stations' sites have been tested for their strength and elastic properties following the requirements of the standards of the Russian Federation. The inverse geo-mechanical problem-solution method based on the registered rock pressure manifestations has allowed reconstructing the stressed rock mass state in potentially bump-hazardous sections of the mine rock mass. The gravitational and tectonic components of the in-situ stress field have been calculated. The results have been compared with the ones previously obtained for the average conditions of the Darasunsky deposit. Based on the research results, the gravitational-tectonic nature of the pre-mining stress-strain state of the rock mass of the Darasunsky field has been confirmed. At the same time, it has been found that the pre-mining stress field is discretely dispersed: there are localized high-stress areas where dynamic stress manifestation is probable, medium-stress areas without visible manifestations of rock pressure, and unloaded sections of the marginal rocks mass. For the engineering geotechnical calculation purposes, a differentiated assessment of the initial stress-strain state has been suggested. It is recommended that the stress be calculated for specific mining and geological conditions, based on the specified relations of the initial stress distribution.

The aim of the work is to study the parameters of hardenable gas-liquid mixtures that can eliminate geological complications in well drilling, i.e. prevent and eliminate absorption, maintain the interval stability of loose rocks, and ensure trouble-free permafrost drilling-in. The study has been conducted for resins based on aggregate shale phenols, expanding mixtures based on phenol-formaldehyde FRV-1A resin and VAG-3 curing agent, and foams based on M-19-62 resin. The following properties of the foam compositions have been studied: viscosity, curing time, filterability, strength and its change over time, adhesion with the rock and metal casing surfaces, setting time, change in the mixture volume after polymerization, viscosity and elastic properties. The research methods include laboratory experiments and field tests at running wells. The study has shown an increase in the tamping quality, i.e. prevention of the gas-liquid mixture early curing and the power intensity reduction when injecting and forcing. A scheme of troublesome zones tamping with foam plastics has been developed. Based on the results of the study, the compositions of hardenable gas-liquid mixtures and their technological parameters have been developed for different geological-and-technical well-drilling conditions. The conclusion is that the developed hardenable gas-liquid compounds ensure higher performance of the drilling process and lower costs of the well construction.

The objective of the work has been to study the centrifugal-jigging method of gold ore concentration as a breakthrough method that reduces the valuable mineral losses in gravity concentration and increases the concentrate grade. Within the framework of the study, the main factors influencing the centrifugal-jigging concentration process, as well as the ways of improving the key parameters of the process, have been investigated. The full-scale testing of the centrifugal jigger has been carried out by the previously developed procedure, in the operation conditions of the gold-processing plants 1 and 2, with additional gold recovery from the plant 1 tailings (P80 0.074 mm) and from the two-stage hydro-cyclone system overflow of the plant 2. The study has shown that gold сan be additionally recovered from the cyanidation tailings and two-stage hydro-cyclone systems by jigging in a centrifugal field. The main factors influencing the centrifugal-jigging separation are the jigging chamber rotational speed, the pulsation frequency and amplitude of the movable cone, and the underscreen-water pressure. The centrifugal jigging concentrator has been patented. The results of the study suggest that in certain cases, jigging in a centrifugal field is a preferential gravity concentration method at the pre-concentration and control stages. For the method to be used at the main stages of the operating plants, the concentrate yield should be reduced to 5-10 %.

The ores of antimony deposits contain sulfide (antimonite, jamesonite, boulangerite, etc.) and oxidized forms of metal (stibiconite, valentinite, cervantite, etc.). The sulfide forms are well recoverable, while the oxidized ones are resistant to all enrichment processes. Thus there is currently no technology for obtaining a proper-quality oxidized antimony concentrate. The survey of the known methods of extracting antimony oxides from antimony ores shows that flotation is considered the most effective method. In the case of antimony ores, separate (sulfide and oxidized) flotation is used. The efficiency of oxidized antimony forms flotation using the existing collectors, modifiers and activators, is low, which makes it necessary to develop higher-efficiency agents and operation parameters of the enrichment process. The present work suggests using a new complex collecting agent in the antimony ore flotation (the Zhipkosha deposit) and describes a quantum-chemical calculation that allows determining the interaction of the reagent with the oxidized antimony mineral forms. It has been found that the flotation using the complex КR-1 collector (in a ratio of 1:1:0.2) results in higher flotation properties of the antimony oxide due to the bigger effect on the monogene surface (lenses, films). This fact is proven by the quantum-chemical calculation that gives the calculated energy of the monogene-agent interaction of 24.1 kJ/mole, which is typical of donor-acceptor interactions. The effectiveness of using the complex КR-1 collector for oxidized metal minerals flotation has been confirmed for the antimony ore sample with an antimony content of 2%. With the concentrate quality of 40 %, the antimony recovery increases by 9.1 %, while the tailings amount decreases from 1.42 % to 1.12 %.

The aim of the research work has been to define the factors causing the destruction of polished granite pegmatite tiles used for indoor flooring. Facing tiles made of various-size-grain and large-to-giant-grain rocks (mica-quartz-feldspar composition) have been studied using a transmitted-light microscopy method (OLYMPUS BX51 microscope and Steindorff stereoscopic laboratory microscope, 170-BD-LED-E model). The natural features of the granite pegmatite that affect the endurance of the facing tiles have been studied, i.e. the mineral composition and structural-textural properties of the granite pegmatite tiles, as well as the mineral percentage, the grain size and interrelationships have been defined. It has been found that that the tile endurance depends on a crystalline-media property connected with the minerals’ internal structure. The studied tiles consist of plagioclase, microcline, quartz, muscovite, biotite, and garnet. The structure is heterogeneous, varying from fine-grain to giant-grain (crystalline-grain), with alternating fine-grain, medium-grain and large-to-giant-grain structure areas. The minerals are mainly hard (6-7 by the Mohs scale of hardness), except for the mica (2-3). The muscovite and plagioclase have perfect and perfect cleavage, respectively. The cleavage is associated with the anisotropic cohesive forces acting among the regularly arranged structural units in the minerals’ lattice. The mica’s cleavage is a slip plane, which affects the endurance of the facing tile and causes cleavage fracture and subsequent chipping and breakdown. The coarse-crystalline plagioclase has perfect cleavage in two directions, i.e. under vertical load it splits in two directions on the cleavage. Thus, a conclusion can be made that the muscovite’s and plagioclase’ crystalline structure causes cleavage fracture of the facing tiles and their further destruction