The article considers the distribution of different ages volcanic formations of Elbrus volcano, PaleoElbrus and autonomous eruption centers within the modern volcanic structure of Elbrus and its environs. The proposed generation sequence of these volcanogenic formations is shown, which was established using the geomorphological method by the morphology of the lava flows’ surface, as well as by the ratio of volcanogenic formations to each other, with Quaternary deposits of other genetic types, and with landforms.

One of the discontinuous faults in the south of the East European Platform — the Semiluki-Lipetsk fault along the border of the Voronezh newest uplift and the Oka-Don trough. Detailed studies using the methods of engineering-geological, geophysical, geodesic, geochemical, structural-geomorphological, etc., accompanied by drilling and field studies, allowed us to determine the type of discontinuity as a extension with the participation of right-strike-slip (dextral shear) stresses. It is associated with fracturing of bedrock and Quaternary sediments, landslides and falls, including large gravitational-tectonic massifs, surface and underground karst, suffusion, and pull-apart depressions. In general, these processes and phenomena affect the geological stability of the site of the nuclear power plant, causing the development of negative processes. The reasons for the extension conditions in the Semiluki-Lipetsk fault zone are considered from two positions — the influence of pressure from the south from the Alpine orogen of the Caucasus and the connection with intra-platform deep processes that cause the extension the earth’s crust under the Oka-Don trough.

Composite paleotemperature curves (values of average annual temperature and sea surface temperature) for high and low latitudes of Northern Eurasia have been compiled. Based on them, a model of the climatic history of the Northern Hemisphere in the Mesozoic-Cenozoic was compiled. The relationship of climate variations with other significant geological events — cycles of eccentricity of the Earth’s orbit, impact events, inversions of the geomagnetic field is analyzed.

The article considers various criteria of the conodont biofacies distinguishing, and principles of conodont paleoecological models reconstructing. The proposed conodont biofacies model is based on conodont distribution in the Frasnian (Upper Devonian) of the Voronezh anteclise (Central regions of Russian Platform).

 The lithological and geochemical characteristics of the Meso-Cenozoic interval of the Leskinskaya well section (the mouth of the Yenisei River) and its  paleogeographic and paleoclimatic characteristics are given. 

The reservoir water content is one of the key parameters to following reliable hydrocarbon reserves estimation of low-permeable shale reservoirs with unconventional hydrocarbon reserves. The extensive review of applied direct and indirect laboratory methods for determining the water saturation in unconventional shale reservoirs is presented in this article. The essence, advantages, disadvantages and limitations of methods are described in detail. It was demonstrated that direct laboratory methods (retort method, Zaks, Dean–Stark) which were originally developed for traditional reservoir rocks, give results with an error of up to 50% for rocks samples of unconventional reservoirs. On the other hand the Evaporation Method specifically developed for low-permeable rocks takes less time and provides more accurate (error up to 6.8%) gravitational and bonded water determination moreover, it requires up to 5 times less rock material for analysis.

 Based on the study of microstructural and geochemical features of bedded cherts of the Inikan Formation (Є_1–2in) from coastal outcrops of the river Yudoma found that the key role in their formation apparently belongs to siliceous organisms — radiolarians and sponges. The Ge/Si ratio indicates that there is no direct contribution of fluids to the formation of cherts in this part of the paleobasin. The studied chalcedony-quartz rocks were formed from primary biogenic silica subjected to diagenetic redistribution and post-diagenetic processes. 

Volcano-edaphogenic material was studied, which was raised by a grab sampler during cruise 53 of the R/V Akademik Ioffe from the water depth of 4685 m in the area of the Vima transform fault. Mineralogy and the distribution of chemical elements between the minerals of magmatic origin are considered. An attempt was made to roughly estimate the crystallization temperature of aphyric basalts. The hydrogenic nature of ferromanganese crusts covering the fragments of magmatic origin is has been clarified. The relationship between the formation of volcano-edaphogenic material and bottom ocean currents is analyzed.

A velocity section was obtained to a depth of about 250 km on the eastern margin of the Sarmatia protocraton (East-European Craton) based on P receiver functions (PRF). Seismograms of the new broadband station «Aleksandrovka» were used as initial data. The section reveals the main seismic boundaries, and also shows the presence of mid-lithospheric discontinuity in the upper mantle (MLD).

The results of natural and man- made seismicity long-term observations on the Eastern European Platform (EEP) according to the data of the small-aperture seismic group (MSG) “Mikhnevo” IDG RAS are summarized. It is shown that technogenic seismicity is dominant in this area. Descriptions of wave forms from blasts at the largest quarries of the Belgorod and Kursk regions are given. Special attention to the assessment of energy from explosions produced at numerous relatively small quarries located in the central part of the EEP is paid. The energy assessment of the total technogenic impact on the environment is given. The results of registration and location of natural-tectonic events that occurred on the territory of the central part of the EEP, previously considered aseismic, are shown. The negative impact on the territories located near the existing quarries from the resulting dust and gas emissions during drilling and blasting and other mining operations was noted.

Recently, there are more and more investigations devoted to plastic pollution of the natural environment. In this case an active attention is paid to microplastic particles (MPs) less than 5 mm size and nanoplastic particles (NPs) less than 100 nm in size. MP and NP particles are found practically everywhere: in waters and bottom sediments of the World Ocean, river, lake and groundwater, beach sediments and even in snow and ice of the Arctic and Antarctic, in foodstuff, bottled water, in living organisms at all stages of the food chain. Plastic pollution of the natural environment has already become as global as climate change. This article presents the results of the analysis and summary of the current published literature devoted to the problems of MP and NP pollution of natural waters, mainly on the territory of the Russian Federation. For the first time, a schematic map of MP distribution in surface waters of Russia is constructed. A summary table on MP concentrations in surface water, groundwater, bottled mineral and tap water, bottom sediments of rivers, seas and oceans of the world is presented. It is clearly shown that there is a shortage of studies of MP and NP contamination in groundwater, although their content is also quite high.
In addition, the paper touches upon the problem of measuring the MP and NP content and determining its composition, highlights the features, advantages, disadvantages and limitations of all the main detection methods. The summarized schemes of water and soil sampling and preparation for the following MP determination are presented. A reasonable conclusion is made that at the present moment there is no one optimum method, and only a combination of methods allows to identify MP and NP contamination in the best way.

The paper presents the results of a study of the chemical composition of the formation waters of the Lower Cretaceous, Jurassic and Paleozoic deposits of two oil fields of the Krasnoleninsky dome of Western Siberia. It is shown that the content of barium in formation waters of the fields is 35–78 mg/dm³, which is an order of magnitude higher than its content in most reservoir brines with a mineralization of about 80 to 260 g/dm³, while the mineralization of the studied reservoir waters does not exceed 16–18 g/dm³. In the waters of the rocks of the Jurassic age, an advancing accumulation of barium was noted, in relation to strontium and almost equal to the calcium content, which was reflected in the Ca:Sr:Ba ratio, which was 100:10:100, while for most reservoir brines and ocean water this ratio is 100:10:0.01. Such an anomalously high content of barium in relation to the salinity of formation waters can be explained by its entry into the sedimentation basin as part of deep thermal waters.

Springs are an essential drinking water resource. Therefore, spring water quality is necessary to control under the increasing anthropogenic pressure on the environment. This study was carried out to evaluate the content of major ions and trace elements in the waters of 28 springs in the Pushkinsky district of the Moscow region. The macro- and micro-component composition of groundwater of various aquifers was characterized according to the sampling data of springs. It is shown that the mean contents of trace elements in the waters of springs are at the level of concentrations characteristic of groundwater in the leaching zone of a temperate climate. Based on the thermodynamic calculation using the Visual-MINTEQ, it was found that the predominant dissolved forms of Ba, Sr, Fe, Mn, Zn, Cd, Ni, Co are free ions in the waters of the surveyed springs, Cu and Pb are carbonate and organic complexes.

 The paper substantiates the need to use geophysical methods in geocryological monitoring to study the conditions of permafrost, search for taliks and cryopegs, and determine the physical and mechanical properties of frozen grounds. Their advantages, disadvantages and examples of their use for solving geocryological problems are described both in natural conditions and in the zone of influence of buildings and engineering structures. 

A complex of geological and geophysical work was carried out to study fracturing in the Jurassic-Neogene rocks of the Heraclea Plateau, which included a field study of the Georgievsky fault zone, structural and geomorphological analysis; the geophysical complex combined marine seismic and magnetometric studies in combination with ground-based studies using electrotomography, gravimetry and magnetometry. The main object of study was the zone of the deep Georgievsky fault and the feathering tectonic disturbances.
As a result of complex studies, the main geological and geophysical criteria for the identification of dangerous fracturing sites have been established: the extremely heterogeneous structure of the upper part of the geoelectric section to depths of 30–40 m according to electrical survey data; seismic data indicate that Miocene limestones have extremely low strength properties in areas of increased fracturing; according to electrical survey data, the water content (humidity) of the upper part of the section changes sharply horizontally; in the karst areas at certain depths, there is a sharp variability in resistivity from the maximum values to the minimum; fracturing develops quite actively under the influence of landslide processes. Especially dangerous are the stretching cracks that occur in areas of positive relief of the base rocks, along which landslide bodies represented by limestones slide.

A variational method of mathematical modeling of seismic wave kinematics has been developed at the Department of Seismometry and Geoacoustics of the Faculty of Geology of Lomonosov Moscow State University for studying the kinematics of seismic waves of different types in two-dimensional isotropic media (gradient and layered) is presented. The problem of determining the trajectories of seismic rays was solved by integrating using the Runge-Kutta method a system of differential equations with given initial conditions. The algorithm was studied in order to verify the accuracy and correctness of the solutions obtained, as well as its testing on a number of theoretical models of heterogeneous media. The developed ray tracing method was used to study the effect of the velocity gradient and the geometry of seismic boundaries on the kinematics of reflected waves in multilayer media. Based on the results of mathematical modeling of the kinematics of reflected waves, conclusions were drawn about the limits of applicability of simplified models of horizontally layered media, which often approximate complex inhomogeneous media.

Experimental studies of the kinetics of dissolution of gypsum-anhydrite rocks in water (25 °C; P = 0,1 MPa) made it possible to formulate a process model in the form of a system of equations for the kinetics of dissolution of gypsum and anhydrite (of the first and second order, respectively). The calculated values turned out to be more comparable with the experimental data, taking into account the common-ion effect on the solubility of gypsum and anhydrite, and changes in their values of the specific reaction surface.