The Shared Research Facilities "Primorsky Centre for Local Elemental and Isotopic Analyses" was created based on the instrumental base of the Far Eastern Geological Institute of the Far Eastern Branch of the Russian Academy of Sciences. The Shared Research Facilities conducts its own (for the needs of FEGI FEB RAS) fundamental and applied scientific research to establish the elemental, isotopic composition and structure of both natural and artificial objects, as well as jointly with other scientific Russian and foreign institutions and universities, industrial enterprises, state and private companies that require modern, precision methods for analyzing various substances and materials, diagnosing and monitoring the condition and changes in the environment.

Shared Research Facilities "Petrophysics, Geomechanics and Paleomagnetism", created based on actively developing divisions of the Schmidt Institute of Physics of the Earth RAS, has advanced research equipment and unique methods, which determines the possibility of solving a wide range of applied and fundamental problems in Earth sciences. The main activities of the Shared Research Facilities "Petrophysics, Geomechanics and Paleomagnetism" are in the field of geomechanical modelling and petrophysics, paleomagnetism, rock magnetism and applied analytical studies of the composition and structure of minerals, rocks and materials. The research results carried out at the Center are used to solve actual problems of prospecting and exploration of oil and gas basins, mineral deposits, tectonics, global geodynamics and tectonophysics. The article presents the scientific equipment of the Center and its key characteristics, describes the methodological and analytical capabilities, and the most significant results of research groups. 

The article presents general information about the interdisciplinary Shared Research Facilities "Geoanalyst" of the Ural Branch of the Russian Academy of Sciences, the main directions of its work, analytical equipment and types of work that allow obtaining quantitative information on the chemical (elemental and isotopic) and phase composition, parameters of the crystal and electronic structure, type and concentration of the lattice defects, optical properties of samples including minerals, rocks, bottom sediments, ores, products of their enrichment and processing, natural and drinking water, as well as synthetic compounds, techno- and biogenic objects. Consideration is being given to the techniques involved in the Shared Research Facilities such as electron probe microanalysis and electron microscopy; X-ray fluorescence, atomic emission and atomic absorption analysis; X-ray structural and thermal analysis; microelement mass spectrometric analysis; isotope mass spectrometric analysis and geochronology; physics and spectroscopy of minerals. Emphasis has been placed on the fundamental and applied sciences based on the Shared Research Facilities, its scientific and educational activities and the experience of working with users. Details have been provided for the formulation, testing and use of microanalytical methods for in situ study of the composition, structure and properties of minerals-concentrators of transition, rare-earth and radioactive d- and f-elements (zircon, titanite, etc.) with a spatial resolution from units to tens of micrometers. There have been analyzed the application and development of research methods; their metrological parameters; the procedure for selection and certification of internal laboratory reference samples; the possibilities for solving problems of fundamental and applied physics and chemistry of mineral matter, as well as geochronological problems.

The SR-micro-XRF method was used to search for microparticles of extraterrestrial matter in the bottom sediments of Lake Zapovednoye, located 60 km from the epicentre of the explosion of the Tunguska cosmic body (TCB) in 1908. The material of bottom sediments dating back to 1908–1910 was studied. The samples for the study were prepared in the form of a powder applied to a conductive adhesive tape, which made it possible to combine the data of optical observations, electron microscopy, and micro-XRF scanning. The experiments were carried out at the Large-Scale Research Facilities "Kurchatov Centre for Synchrotron Research" using a confocal X-ray microscope developed at the Budker Institute of Nuclear Physics SB RAS. The data obtained indicate the presence of microparticles with an increased Ni/Fe ratio, possibly of extraterrestrial origin.

The article discusses the history of the development of analytical research at the Institute of the Earth’s Crust, Siberian Branch of the Russian Academy of Sciences over the past 22 years. An overview of the existing scientific equipment, current analytical techniques and some examples of their application in geological research are provided. It is shown that the availability of highly qualified personnel and modern scientific equipment at the Center for Geodynamics and Geochronology allows, both entirely on its base and in cooperation with other Russian and foreign organizations, to conduct state of the art research with the publication of results in leading international journals.

The Shared Research Facilities "Geospectrum" of the Geological Institute SB RAS (Ulan-Ude) was created based on the analytical base of the Geological Institute SB RAS (GIN SB RAS, Ulan-Ude). Its equipment is used for isotopy of light elements, U-Th-Pb geochronology of igneous, metamorphic and sedimentary rocks. In addition, a large volume of mineralogical and geochemical research is carried out to solve petrological, geochemical, lithological-geochemical and environmental basic and applied problems.

The "AIRES" Shared Research Facilities (SRF) is a high-tech laboratory complex based on the Institute of Precambrian Geology and Geochronology RAS (IPGG RAS, St. Petersburg). The Institute conducts geological, mineralogical, geochronological, isotope-geochemical and paleontological studies aimed at solving the problems of the formation and evolution of the Earth's continental crust in the Precambrian and Phanerozoic. The methodological developments of the "AIRES" SRF make it possible to interpret the conditions of occurrence of igneous, metamorphic and sedimentary rocks and minerals, as well as their age. The ongoing research includes studies on geology, geodynamics, stratigraphy, petrology, lithology, isotope geochemistry, geochronology, as well as paleogeography, archeology, soil science, ecology, and chemistry.

Centre of Isotopic and Geochemical Research based on the Analytical Department of Vinogradov Institute of Geochemistry SB RAS (Irkutsk) performs a wide range of analytical studies to solve mineralogical and petrological, geochemical, prospecting, ecological, paleoclimatic and applied problems. The studies are supported by the modern equipment for electron microprobe, X-ray diffraction, X-ray fluorescence, atomic emission and mass spectrometric (including isotope) analyses, as well as the necessary international certified reference materials (SRM) and a collection of SRM of the natural and technogenic composition of our production.

The activity of the North-Eastern Shared Research Facilities of the Shilo North-East Interdisciplinary Scientific Research Institute, Far Eastern Branch of the Russian Academy of Sciences (NEISRI FEB RAS) is aimed at conducting analytical studies of rocks, minerals, ores, soils, lake and sea sediments, water bodies using various methods: optical microscopy, X-ray microanalysis, X-ray fluorescence analysis, quantitative emission spectral analysis, atomic absorption spectrometry, isotope geochronology, paleomagnetism and petromagnetism. The results of mineralogical, geochemical, petrophysical, isotope-geochronological (including radiocarbon) and palynological studies have been published in national and international scientific journals.

The article presents a Large-Scale Research Facilities "Arkhangelsk seismic network". The configuration, technical equipment, methods of processing earthquakes on the platform and the Russian part of the Arctic are presented. The actual results of the Large-Scale Research Facilities "Arkhangelsk Seismic Network" are discussed.

The Southern Baikal is located within the actively developing Baikal rift zone (BRZ) that is characterized by a significant seismic potential, and M>7 earthquakes occur periodically with intensive shaking in the epicenters (up to 10 units). The problem of prediction and forecasting of strong earthquakes has always been critical for this region, considering its increasing urbanization, industrial clusters and transport systems. The article describes the methodology based on rock deformation monitoring data, which aims at developing a technology capable of efficient prediction and forecasting of strong earthquakes. In the Institute of Earth’s Crust SB RAS a set of studies is carried out in order to solve this problem, including those associated with the instrumental study of current movements of the lithosphere through GPS geodesy and deformations of rocks by strain gauges. The existing GPS sites and deformation measurements are combined into the Large-Scale Research Facilities "South Baikal instrumental complex for monitoring hazardous geodynamic processes" in frame of the Shared Research Facilities "Geodynamics and Geochronology" at the Institute of the Earth’s Crust, Siberian Branch of the Russian Academy of Science.

In this article, the deformation monitoring methodology is described in application to the monitoring sites installed in the study area. The description includes the details of its conceptual basis, technical support and data processing methods. The discussion focuses on the instrumental measurements of rock deformation related to three strong events in the study area – Kultuk (August 27, 2008), Bystrinskoe (September 21, 2020), and Kudara (December 10, 2020) earthquakes. The features of the deformation process before these seismic events are given special attention with account of the structural-geodynamic settings and positions of local monitoring sites relative to the earthquake epicenters.

The article provides an overview of vibroseismic studies carried out in the Baikal rift zone using LargeScale Research Facilities – a powerful CVO-100 seismic vibrator, installed at the South Baikal geodynamic test site SB RAS. Research is carried out according to several methods focused on different tasks: study of the structure of the Earth’s crust and upper mantle in the BRZ, active vibroseismic monitoring, and verification of velocity models of the Earth’s crust. To study the structure of the Earth’s crust and the upper mantle, there were done the vibrator-generated wavefield recordings at the stationary regional network of seismic stations in the Buryat and Baikal branches of the Federal Research Center of the GS RAS, as well as the experimental studies involving the mobile networks deployment (ICMMG SB RAS, SIPE RAS, GIN SB RAS). The aim of the work is to carry out deep vibroseismic sounding of the Earth’s crust (vibro-DSS) at the junction of the Siberian platform, the BRZ and the Sayan-Baikal folded area. The methodology is based on the study of vibration seismograms with the determination of arrival times of the main groups of waves and their correlation with the velocity models of the Earth’s crust in the BRZ. A CVO-100 vibrator and a regional network of seismic stations are used to carry out active vibroseismic monitoring of the southern part of the BRZ. The active monitoring area is about 500×200 km. During vibroseismic monitoring, there were done thorough studies of seasonal variations of the vibrator-generated wavefield and the development of techniques for spectral correction of seismograms. A seismic vibrator CVO-100 was used to carry out experimental verification of the velocity models of the Earth’s crust, developed based on the BEST and PASSCAL experimental data. The vibrational deep seismic sounding (vibro-DSS) on the Baikal – Ulan Bator profile was carried out by the ICMMG SB RAS, GIN SB RAS and BB FRC GS RAS (Russia) in cooperation with IAG MAN (Mongolia). 

Presented here are the descriptions of the Large-Scale Research Facilities (LSRF) «Mid-latitude complex of geophysical observations "Mikhnevo"» at the Institute of Geospheres Dynamics of the Russian Academy of Sciences. The composition of the measuring complex, equipment and applied techniques are provided. The paper also presents some of the scientific results obtained at the LSRF «Mikhnevo» in recent years.

The description of the Unique Large-Scale Research Facilities "Seismic infrasound array for monitoring Arctic cryolithozone and continuous seismic monitoring of the Russian Federation, neighbouring territories and the world" (URF SIA MAC), its hardware and software components are presented. Methods and principle areas of research carried out using the URF are outlined. The URF SIA MAC includes 364 seismic stations throughout Russia and three infrasound arrays. The data obtained at the URF serve to provide domestic fundamental and applied research in the field of Earth Sciences (seismology, geophysics, geodynamics, geoecology) and to study catastrophic events of a natural induced nature. The modern URF data archive includes digital seismic records since 1993. In addition, there is a significant amount of analogue records (since 1904) available for further digitization. The URF SIA MAC provides seismological data to many Russian scientific, research and design organizations. The article presents the main results of the Federal Research Centre Geophysical Survey of the Russian Academy of Sciences obtained in recent years using the URF data.

Information is presented about the Bystrov vibroseismic landfill near Novosibirsk, which houses Large-Scale Research Facilities with no analogues in the world – powerful 50–100-ton vibration sources (GRV-50, CVM-100, CV-40). The infrastructure of the landfill, the composition of the equipment, the tasks of scientific research, Russian and foreign performers of developments are described. The main research results of fundamental and practical importance are presented. One of the main tasks that the created polygon is aimed at is active vibroseismic monitoring with powerful vibrators. The repeatability and accuracy of monitoring, which is one millisecond in kinematic parameters, is shown; the existing monitoring scheme and prospects for increasing the monitoring area due to a stationary seismological network of stations are presented. An example of one of the promising fundamental developments is shown – the study of seismic emission during the excitation of a powerful low-frequency impact on the environment.

The paper considers an experimental complex of the Shared Research Facilities "The Angara" of ISTP SB RAS. Although the centre aims to study Near-Earth space, scientists could use some equipment for research in geodynamics. We mainly described the Siberian network of receivers of signals from global navigation satellite systems SibNet that currently includes ten receiving points. We also provide information on the fields where "non-geodynamic" equipment can be used for multidisciplinary studies of lithospheric processes.

The relevance of the work is determined by the necessity to develop the hardware part of the seismic subsystem of the Large-Scale Research Facilities functioning at the Federal Research Center of the Geophysical Survey of the Russian Academy of Sciences to study seismic signals in groundwater pressure changes. For this purpose, the well monitoring on the territory of the Petropavlovsk-Kamchatsky test site, Kamchatka Peninsula, was updated using Keller equipment, Switzerland (sensors of PAA36 XiW CTD Si, PAA36 XiW modifications, data logger GSM-2), Campbell Scientific Inc, USA (CR6 and CR1000 data loggers) and a budgetary hydrogeodynamic data recorder (HDDR) based on the STK-1 minicomputers, created at the Kamchatka Branch of the GS RAS. A description has been provided concerning the sets of digital equipment installed in four wells for precise recording of groundwater pressure variations with a frequency of 20.00–0.08 Hz. Consideration is being given to the characteristics of the equipment installed in individual wells and to the problems solved in the process of updating the well observation system in order to study vibration effects and hydrogeodynamic precursors of earthquakes. The paper presents the newly obtained results of recording the high-frequency variations in groundwater pressure in wells during the 2020–2021 local and remote earthquakes. A discussion is provided of new possibilities for studying vibration effects on changes in ground water pressure with a frequency comparable to the frequency of recording seismic events by seismometric equipment. Using a new equipment for recording water pressure in the unique well E-1 made it possible to record, a hydrogeodynamic precursor in real time before the March 16, 2021, Mw=6.6 earthquake which occurred at the epicentral distance of 350 km from the well.

The distribution and speciation features of gold in ores and minerals of the Natalkinskoe gold deposit (North-East Russia) are studied using light microscopy (LM), scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDX), X-ray electron probe microanalysis (EPMA), "phase" chemical analysis with atomic absorption spectrometry (PCA-AAS) and atomic absorption spectrometry with analytical data selections for single crystals (AAS-ADSSC). The vein and streaky-vein ores are high-grade ores, whereas veinlet-disseminated ores are less rich and disseminated ores are poor in gold. Up to 85 % of the gold in the ores is in a free native state, associated with quartz and sulfide minerals. LM, SEM-EDX and EPMA reveal that the predominant gold grains are 0.01 to 2.00 mm in size and at a fineness of 720 to 900 ‰. The finely dispersed and submicron elemental gold particles (Au⁰) amounted to 20 % and are mainly enclosed into arsenopyrite and pyrite. According to PCA-AAS data, the highest Au concentrations (up to 1383 ppm) are recorded in arsenopyrite; lower contents are typical of pyrite (up to 158.2 ppm). In these sulfides, two non-mineral species of "invisible" Au are the structurally bound and surface-bound species recognized by AAS-ADSSC. The structural Au is included in the mineral structure. The surface-bounded Au prevails and is confined to nano-sized, non-autonomous phases (NAPs) on the sulfide surface. In common with "invisible" Au, the micro-sized particles of native gold are often observed on the surface and within the surface layers of sulfide crystals. This is consistent with the model of post-growth transformations of nano-sized NAPs, resulting in the formation of nano and micro-sized Au⁰ particles. It is expected that the major part of gold contained in arsenopyrite and pyrite as finely dispersed and submicron particles, as well as the surface-bound gold in NAPs, can be won with modified current schemes of gold concentration, which enhances the value of the gold ore mining.

We assessed the contents of Fe, Ni, Cu, Zn, As, Cr, Pb, Hg in soils of the residential settlements and surrounding areas exposed to anthropogenic load due to mining activities. The study object is located in the Kuznetsk Alatau (part of the Sarala gold ore cluster – SGOC), the village of Priiskovy and its tailings dump, the village of Ordzhonikidzevsky, the Republic of Khakassia). The background contents in the SGOC soils are the following: Fe 3.08–5.06 %, Ni 24.74–45.13 g/t, Cu 22.33–38.81 g/t, Zn 86.72–200 g/t, As 5.45–11.25 g/t, Cr 35.60–73.25 g/t, Pb 14.12–26.17 g/t, Hg 0.01–0.14 g/t. It was found that the background area has increased the natural contents of the studied elements. The soils sampled from the territory of the tailing dump are distinguished by the elevated element contents relative to the background values and especially by a sharp jump of the As and Zn contents (abnormal contents). The contents of all the elements examined in the soils of the territories in the vicinity of the tailing dump also exceed the background values of the SGOC with different proportions of cases and have the increased As, Cr, and Pb contents relative to the maximum permissible concentration of soils. Clustering of the data shows the presence of two clusters, which indicate the availability of the background and anomalous values associated with the technogenic impact of the mining industry in the study area of the Sarala gold ore cluster.

A comprehensive study of the stratotype section of the Kinterep formation of the North-Western Salair was carried out, including geochemical and isotope (Sr, C, O) studies of carbonate rocks, and U-Pb dating (LA-ICP-MS) of igneous zircon crystals from tuffites. The studied carbonate rocks are pure limestones with Mg/Ca less than 0.007 and a low proportion of insoluble residue (average 5 %). Kinterep limestones are characterized by δ¹⁸O_SMOW values from 19.8 to 23.8 ‰ and δ¹³С_PDB values from –0.7 to +0.9. The Sr isotope composition in limestones of the Kinterep formation varies in a narrow range of ⁸⁷Sr/⁸⁶Sr values between 0.70851 and 0.70859. Comparison of the obtained isotopic characteristics (⁸⁷Sr/⁸⁶Sr and δ¹³С_PDB) of Kinterep formation limestones with the generalized global ⁸⁷Sr/⁸⁶Sr variation curve and δ¹³С_PDB values in the pale-ocean suggests two equally probable interpretations of the time of accumulation of Kinterep formation limestones: 550–540 and 525–510 Ma. U-Pb dating of magmatic zircon crystals from tuffite, which forms an interlayer among limestones of the Kinterep formation, showed the age at the boundary of ~515 Ma. Thus, using a combination of isotope (Sr, C) chemostratigraphy of carbonate rocks and U-Pb dating of igneous zircon crystals from tuffites syngenetic to limestones, the age limit of 525–510 Ma was established for the time of the formation of the Kinterep formation of the Salair basin. Carbonate rocks of similar age and similar features of the isotopic composition are known in neighbouring areas (for example, the Kuznetsk Alatau) and in regions of the Siberian Platform and microcontinents of Central Asia (Tuva-Mongolian and Dzabkhan) spatially distant from the Salair basin.

This paper considers chemical and analytical aspects of the preparation of samples of marine ferromanganese deposits (FMD) by stepwise selective leaching to determine their phase composition. The behaviour of samples with different mineral and chemical compositions at various stages of their preparation was studied on the base of the FMD sample from the Eastern Pacific. The paper shows the necessity of further scanning-electron-microscopy (SEM) method-based research to control the complete dissolution of Fe compounds responsible for accumulating trace elements, which are geochemical indicators.

The first results of U-Pb LA-ICP-MS dating of 150 detrital zircon grains from the Upper Permian sandstone of the Boyevaya Gora section (Orenburg region, the Southern Cis-Urals) are presented. 95 conditional zircon U-Pb isotopic dates form two age peaks – 381 and 529 Ma. It is assumed that clastic material entered the sedimentation basin mainly due to erosion of the Early Hercynian Ural complexes and relics of the Protouralian-Timanian orogen. 

Unlike conventional X-ray fluorescence spectrometry, the total-reflection X-ray fluorescence spectrometry is not a widespread and routine method for analyzing solid samples with mineral matrix, but it has a great potential for geochemical, geological, and archaeological studies. Rapid multi-elemental analysis of very small sample amounts can be performed by the internal standard method which does not require the matrix-matched reference materials. This is an undoubted advantage of the TXRF method over the conventional X-ray fluorescence method, especially if there is a limited available sample amount and a lack of well-characterized reference materials. This paper presents our experience with the application of TXRF spectrometry in the elemental analysis of apatite, ceramics, sediments, ores, and nodules. Special attention has been paid to the sample preparation procedure because it is one of the main sources of errors in the analysis. Preparing thin homogeneous specimen from the solid sample with a complex mineral matrix is not easy. Sample preparation strategy should be chosen considering the features of an analytical object, the content of the elements to be determined, and the accuracy required for a reliable interpretation. Consideration is being given to the examples of the preparation of a suspension for rapid analysis of ores and sediments, and to the original techniques of chemical decomposition for apatite and ceramics.

⁸⁷Sr/⁸⁶Sr isotopic ratios are widely used to identify strontium sources and study strontium behaviour in(bio)geochemical cycles. ⁸⁷Sr/⁸⁶Sr in surface waters can reflect the average composition of bioavailable (i.e. available forfurther absorption by plants and animals) strontium in the catchment specific area. Based on those ⁸⁷Sr/⁸⁶Sr ratios, theregional maps of the bioavailable strontium distribution (strontium isoscapes) can be compiled. A complex block structurecharacterizes the Ural mountain system. Individual parts (blocks) are composed of rocks of various ages, genesis andgeochemical characteristics, which can radically change at a distance of several tens of kilometres. Such variability wouldbe reflected in strontium isotopic ratios, thus making it possible to determine the local isotopic signatures of bioavailablestrontium.

This work aimed to study ⁸⁷Sr/⁸⁶Sr in the water in the rivers of the Southern Urals. We determined the contents andisotopic ratios of strontium in river water samples collected from the territories of the Orenburg and Chelyabinsk regionsand the Republic of Bashkortostan in 2019–2020.

For the first time in the surface water of the rivers in the Southern Urals (Ural, Belaya, Tobol, Karagaily-Ayat, Sim, andothers), the ⁸⁷Sr/⁸⁶Sr isotopic ratios have been determined, and their variations have been analyzed. ⁸⁷Sr/⁸⁶Sr values varyin the range 0.70666–0.71063 (average 0.70908) for the rivers of the Urals basin, 0.70749–0.71058 (average 0.70924)for the Kama-Volga basin, 0.70946–0.71176 (average 0.71071) for the Tobol basin. Such features of the strontium isotopiccomposition may be due to the influence of underlying rocks of the catchment area drained by river water. The dataobtained can be used to identify the sources of strontium input into the water system during hydrological and environmentalstudies; to confirm the authenticity of food products of plant and animal origin; to carry out comparisons in thestudies of the migration of ancient people and animals, as well as to determine the raw material areas for the productionof vegetable and woollen textiles and wooden products in antiquity.

In order to develop express methods for the quantitative assessment of properties and the selection of reference samples close to investigated sample, to ensure similar conditions for the evaporation of substances and parameters of fractionation of trace elements in LA-ICP-MS, a comparative analysis of the U-Pb isotopic composition, Raman and cathodoluminescent spectra of zircon GJ-1, Plesovice, 91500, Temora-2, Mud Tank reference samples has been performed. Variations in the position and width of the full width at half maximum (FWHM) mode of asymmetric stretching vibrations ν₃(SiO₄) B_1g, as well as the values of the accumulated autoradiation dose D_α and the equivalent dose D_α^ed have been analyzed. It has been shown that in the series Mud Tank→91500→Temora-2→GJ-1→Plesovice, an increase in the degree of autoradiation damage is recorded: the first three samples are slightly damaged; Plesovice is a moderately damaged difference. The analyzed reference samples can be correctly used for LA-ICP-MS analysis of samples of weakly damaged zircons from magmatites, as well as fragments (zones) of zircon grains from metamorphic rocks of weak and medium degree of structural damage. For the first time, using a Jeol JSM6390LV SEM equipped with a Horiba H-CLUE iHR500 attachment, cathodoluminescence spectra of zircon reference samples were obtained in the 200–800 nm range. It has been found that the integral luminescence brightness varies for samples by more than an order of magnitude; the spectra are of a complex superposition nature; their decomposition into elementary components is ambiguous; a large number of components is detected, which are combined into three main А_i–В_i–С_i groups of broad bands in the near-ultraviolet (UV), blue-green and yellow regions with E_max=4.3–5.0, 2.6–3.5, and 2.1–2.3 eV, respectively. For the first time, it was

proposed to use a triple А_i–В_i–С_i diagram to discriminate zircons by their luminescent properties. It has been found that the position of zircon standards on it significantly differs, which is proposed to be used as a basis for an express assessment of their properties and selection. A comparative analysis was performed on the U-Pb isotopic composition, discordance of age determinations, features of Raman and cathodoluminescence spectra for a large sample of accessory zircon from kimberlites and diamond-bearing placers of Yakutia, as well as metamorphic rocks of the Urals – from granite of the final phase of the Neplyuevsky pluton, high-magnesian diorite massif, from high-pressure garnetites of the Mindyaksky lherzolite massif, from leptinites of the Taldyk block Mugodzhar. The А_i–В_i–С_i diagram is compared with similar data on the cathodoluminescence of the reference samples.

On the one hand, the widespread use of electron microprobe analysis in the version of a scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS) and, on the other hand, the comparability of the metrological characteristics of the EDS and wavelength dispersive spectrometry (WDS) in the case of determining the major components of minerals are a favourable background for investigating the possibility of using SEM-EDS for chemical dating of uranium mineralization. Carbonaceous-siliceous formations of the Dabanzhalga suite are widespread in carbonate deposits of the Lower Paleozoic in the Oka structural-formational zone of the East Sayan and represent deep-water deposits of the back-arc basin. All varieties of carbonaceous-siliceous rocks of the Dabanzhalga suite are characterized by increased U, Au, Ag, Pt, Pd, Mo, V, P, Cu. Their amounts are 5–10 times higher than those for other black shale deposits of the Eastern Sayan. Uranium forms its minerals – uraninite and brannerite, in association with carbonaceous matter and sulfides, and is also part of anhydrous phosphates – xenotime, monazite. The paper presents data on the composition and dating of brannerite and uraninite in samples of carbonaceous-siliceous shale sampled at three sites: Uber-Zhadoy, Deed-Khara-Zhalga and Erye-Khara-Zhalga. The obtained estimates of the isochronous dates of uraninite and brannerite grains for these areas are 523±26, 506±10, and 511±17 Ma, respectively. It was shown that these dates could be compared with the age of metamorphism at the Sukhoi Log deposit, estimated using modern methods of isotope geochronology. It should be noted that the average estimates of the dates of uraninite and brannerite in all studied areas of the Dabanzhalga suite are lower than the corresponding estimates of the isochronous date, which is probably due to the partial loss of radiogenic lead. For the Uber-Zhadoy site, a comparison of the EDS and WDS data was carried out, and it was shown that when using the EDS data, there is an underestimation of the Pb content in uraninite, and, as a consequence, an underestimation of the age of uraninite. 

Inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation (LA) are widely used to study the trace element composition of minerals, including silicates; nevertheless, methodological activities in this area aimed at increasing the sensitivity and locality and reducing composition error, remain relevant. The paper describes methodological approaches for studying the trace element composition of a number of silicate minerals using NexION 300S quadrupole ICP-MS with an NWR 213 LA attachment, obtained on standard synthetic glasses NIST SRM 612 and 610, as well as a number of interlaboratory zircon standards Mud Tank, GJ-1, 91500, Plesovice, Temora-2 and clinopyroxene samples 1636 and 1780 from clinopyroxenite of the Nizhniy Tagil massif (Urals). Presented here are the metrological characteristics of the analysis technique (the accuracy in the determination of elements from Li to U) and variations in sensitivity for different elements, obtained with a crater diameter of 13, 20, 25, 50 and 100 microns. The MS sensitivity drift analysis has been performed through an 8-hour analytical session; a comparison has been made between the results obtained and the literature data; a satisfactory agreement of the results has been observed. The analytical errors allow the use of methods for conducting research in solving various geochemical problems.

The Kovykta-Khandinskaya zone, which includes the Kovykta gas condensate field, is a giant located in the junction zone of the Angara-Lena stage with the craton edge – the Cis-Baikal trough. Here, according to the results of long-term geological exploration, the Verkhnelenskoe uplift was identified, the northern part of which is reflected on tectonic maps as the Kovykta ledge. At the same time, the geological model of the field today is based on the standard two-member model, which includes a slightly disturbed sedimentary cover and basement. However, new geophysical studies revealed that the sedimentary cover of the eastern part of the zone is intensely deformed and has a two-tiered nodular-thrust structure (the lower layer is autochthon, the upper layer is allochthon). The main object for gas exploration within the Kovykta gas condensate field is the Vendian formation. The middle (halogen-carbonate) section has been studied fragmentarily, mainly as an object of geological geohazards when drilling deep wells. The involvement of new data from 3D seismic and 3D transient electromagnetic methods made it possible to clarify the Kovykta gas condensate field tectonic structure to assess the potential of secondary carbonate reservoirs characterized by intense fluid (natural gas, brines) inflows.

We carried out layer-by-layer scanning (with a step of 1 mm) of the bottom sediments of the thermal lake Fumarolnое with SR-XRF (X-ray fluorescence analysis using synchrotron radiation). The lake is located in the caldera of the Uzon volcano (Kamchatka). The section of the bottom sediments of lake IV Fumarolnое covering the time interval from 260 AD to 2012 is diverse in chemical and mineral composition. Two pyroclastic horizons are observed. The chemical composition of the bottom sediments showed the presence of different layers in which such chemical elements as: Ca, Sr, As, Sb, Mo. Cluster analysis performed for chemical elements revealed the boundaries of layers with different geochemical characteristics. The boundaries of these layers coincide with the horizons identified by mineralogical analysis. At the same time, statistical methods of geochemical data processing allowed unambiguously identifying pyroclastic horizons by elemental composition. We show that the data of SR-XRF analysis in conjunction with cluster analysis can be used to separate the gravity core into layers. The data are in good agreement with the separation data into layers using mineralogical methods.

Here we present the results from an in situ Raman thermal spectroscopy study on specific features of the lattice dynamics of scheelite-type compounds (natural and synthetic scheelite, synthetic CaMoO₄ and SrMoO₄) in the temperature range of 83–873 K. Spectroscopic data processing has been carried out based on both classical "peak fitting" and statistical approaches. It has been suggested that an increase in temperature causes nonuniformity of MoO₄ and WO₄ tetrahedra transformation. It has been assumed that dynamics in thermal expansion of unit cells of Ca-containing compounds is slower than that in thermal expansion of WO4 (MoO₄) polyhedral. This diffence is mainly due to the fact that thermal expansion is mainly defined by the expansion of CaO₈ (SrO₈) polyhedra.

Apatite is typically characterized by a wide variety of spectrum and kinetic characteristics of luminescence; luminescent images of grains are often zonal. A variety of conditions for the formation of the mineral in various types of associations and in many types of host rocks contributes to the occurrence of impurities of various luminogen ions in its structure. The variety of luminescence is associated with impurities of d-metals, REE, different types of anions, as well as with the effects of co-activation in various combinations. The paper presents the results of a comparative study of photo-, cathode- and synchrotron luminescence of apatite (by the example of samples from crystal-bearing deposits of the Neroi region, Subpolar Urals). Using a Jeol JSM6390LV SEM equipped with a Horiba H-CLUE iHR500 attachment, cathodoluminescence spectra of apatite were obtained in the 200–800 nm range. The spectra and kinetic characteristics of apatite luminescence upon excitation by synchrotron radiation at 10 and 300 K have been analyzed for the first time; the physical nature of the excitation bands of the three main luminescence centers Ce3+, Eu2+ and Mn2+ has been examined; it is shown that the luminescence excitation with the energy transfer can be carried out in processes initially initiated by interband transitions or photoionization. The data obtained are important for expanding the possibilities of mineral cathodoluminescence with spatial and spectral resolution and its use in applied problems.

It is now known that coals throughout the world contain many valuable elements. In the Irkutsk Region, coal mining is provided by the resources of the Irkutsk coal-bearing basin. The Irkutsk basin is a large area of the Jurassic continental sedimentary deposits in the south of the Siberian craton, with the Cheremkhovo, Prisayan and Kuda formations. The upper Cheremkhovo formation is the primary coal-bearing formation of the Irkutsk basin. This paper presents the geochemical data on the Karataevsky coal mine. Trace element concentrations were obtained using X-ray fluorescence spectrometry. The average Th content (14.24 ppm) in the studied coal seam is higher than that in most of the world coals. The Co (35 ppm), F (1008 ppm), Sn (12 ppm), Th (34 ppm) concentrations in the coal shale consisting primarily of kaolinite (90 %) are higher than in ordinary coals. The coals should be used considering the concentrations of potentially hazardous elements that are high relative to the world coals. The studied coals can be interesting in terms of their slight enrichment in Y, with an average concentration of 19.7 ppm, which is 2.4 times higher than that in the world coal.

First detrital zircon geochronology data and results of geochemical studies for clastic rocks of the Rymnik and Nabil zones of the East Sakhalin accretionary terrane, located within the region of the East Sakhalin Mountains, are presented. The studies have been carried out at the Center for Collective Use of Far Eastern Geological Institute of the Far East Branch of the Russian Academy of Sciences in Vladivostok. The established geochemical features suggest that the source of the clastic material of the zones was felsic rocks of the deeply eroded continental island arc or arcs. Although the geochemical characteristics are similar, there are sharp differences between the detrital zircons’ age distribution patterns of rocks of these zones. In the sandstone of the Nabil zone, 75 % of the zircon grains are of the middle Cretaceous age (94–108 Ma) with a peak of 96 Ma, 15 % are the middle Permian-Early Jurassic, and 10 % are the Precambrian (mainly Paleoproterozoic). The sandstone of the Rymnik zone has a more complex (polymodal) pattern of the detrital zircon age distribution, with a significant contribution of the Precambrian grains (37 %). Most of the grains belong to the Early Jurassic (peak 196 Ma) and the Early Cretaceous (peak 137 Ma), with 47 % of the Mesozoic grains. The likely provenances of the clastic material were the Middle Cretaceous volcanic arcs of the Asian eastern margin older complexes of the continent.

The ICP-MS determinations have been made on microelement content of ~650–640 Ma ultramafic lamprophyre-aillikite dikes and alkaline silicate rocks and carbonatites from the Bolshetagninsky ijolite-syenite massif, spatially overlapped in the northern Urik-Iya graben on the southwestern margin of the Siberian craton. There have been identified two types of spectra of microelement distribution, typical of the Bolshetagninsky massif aillikites and alkaline silicate rocks, respectively; both types of spectra demonstrate significant (more than two orders of magnitude) enrichment in most incompatible elements relative to the primitive mantle. Aillikites have tilt-left distribution spectra of rare elements with Rb, К, Pb, Sr-P, Zr-Hf, ±U minimums and less-pronounced Y minimum. Multi-element spectra of ijolites-melteigites are characterized by Th, Та, Pb, Hf, ±Zr, ±Ti minimums which is also reflected in nepheline syenite and carbonatite spectra. The Bolshetagninsky massif aillikites and alkaline rocks differ also in Nb/Ta, Zr/Hf, Th/Nb, Th/U ratios. Geochemical differences imply that the parental melts of dike aillikites and alkaline rocks are derived from different mantle sources.

The isotopic composition of copper is of great interest for researchers in various fields of science, geochemistry and hydrology in particular, wherein the consideration is being given to the variations in the isotopic composition of the Earth’s crust, extraterrestrial matter, and water basins, as well as to the origin and transfer of matter. Zn isotopes appear to be promising for identifying the sources and pathways of the environmental pollution. The aim of this study involves the refinement and validation of the zinc and copper isotopic ratio determination methodology covering the whole process from sample digestion to MC ICP-MS measurements. For this reason, as well as to assess the suitability of the methodology for the analysis of environmental samples, Zn and Cu isotopic analysis of the BHVO-2, BCR-2 and AGV-2 USGS certified reference materials has been performed. The method for determination of Cu and Zn stable isotope ratios by multi-collector inductively coupled plasma mass spectrometry in environmental samples is developed. The application of the AG MP-1 resin with optimized layer parameters (resin bed height 3.5 cm, diameter 1 cm) provides the high-purity Cu and Zn fractions. The method is characterized by high throughput and adequate analytical figures of merit when using the standard-sample bracketing technique for mass bias correction. The procedural blanks related to chemical dissolution and ion exchange procedures are lower than 1 and 3 ng for Cu and Zn, respectively, assuring no blank effect on the isotopic composition of samples. The accuracy and precision obtained for Cu and Zn isotope measurements in the BHVO-2, BCR-2 and AGV-2 geological certified reference materials demonstrate good agreement with the reference values published.

A critical element in the construction of tectonic models of exhumation of basalts that have undergone high-pressure metamorphism is the diagnosis of synchronicity and the genetic relationship between deformations and high-pressure metamorphic changes. In this report, these issues are discussed on the example of the metabasalts of the Chara ophiolite belt. In the bottom of the basalt block with the separation of pillow lavas near the Burshabulak farm, crack-vein systems with high-pressure mineral associations were discovered and analyzed, which directly indicates their tectonic origin. It is shown that the conditions for the formation of such vein mineral associations correspond to eclogite-like rocks (P=18.5 kbar temperatures of no more than 520 °C). The age of the high-pressure metamorphism basalts of the synchronous type with deformations according to ⁴⁰Ar/³⁹Ar isotope dating of amphiboles cannot be younger than the boundary of 452±14 million years.

The article provides an evaluation of thermal metamorphism temperatures on chondrite parent bodies using an olivine-Сr spinel geothermometer. To calculate temperatures, the results of EPMA analysis of the major and trace elements in olivine and Cr spinel of Kargapole, Orlovka, Saratov, Elenovka, Buschhof, Bjurböle and Knyahinya meteorites are used. The obtained temperatures are consistent with the onion-shell model of the planetesimal structure, in which the most metamorphosed chondrites are closer to the heating source (Buschhof, L6-734 °C), meteorites of the 5th petrologic type (p.t.) occupied an intermediate position (Orlovka, H5 – 687 °С; Elenovka, L5 – 691 °С; Knyaginya, LL5 – 700 °C), and the chondrites of the 4th p.t. were closer to the surface (Kargapole, H4 – 691 °C; Saratov, L4 – 670 °С; Bjurböle, LL4 – 682 °C). The Kargapole and Saratov meteorites are characterized by evaluation of Mg and Fe equilibrium temperatures that disagree with the onion-shell model, which can be explained by the individual history of the meteorite (for example, impact metamorphism, slow and prolonged heating).

A study has been conducted on the features of distriburion of Au among the fractions of a 7-step sequential extraction procedure using model substances that are similar in composition to natural organic matter from the dispersion train of sulfide tailings. Use has been made of model substances with known Au speciations: bulk native gold, nanoscale native gold, Au-containing pyrite, humic acids, and Fe(III) oxides/hydroxides, which served as the basis for preparing mixtures with low-Au filler substances (quartz, limestone, humic acids, Fe(III) oxides/hydroxides).

It has been stated that several Au species are leached in one fraction during sequential extraction. Nanoscale Au⁰ and gold bound to the organic matter are leached together in easily oxidizable (organic) fraction; gold bound to Fe(III) compounds and Au complexes chemisorbed on the surface of other minerals (sulfides, aluminosilicates) are leached in reducible (hydroxides) fraction; "invisible" gold in sulfides, nanoscale Au⁰ and, partially, >1 μm-seized bulk Au⁰ are leached in hardly oxidizable (sulfidic) fraction. Bulk native gold is leached predominantly in residual fraction. Mobile species are Au bound to water-soluble organic compounds and complexes of ionic Au desorbed from the surface of minerals.

The paper provides an example of the first stratigraphic application of ecogeochemical method based on the analysis of the carbon isotope values in conodont elements. The method is based on hypothesis of almost isochronic regime change (at least within the basin) in isotope fractionation of carbon in pelagic ecosystems which is reflected and kept in carbon isotope composition of conodont elements. This method has been used to compare between different facial Frasnian sequences of the northwestern Russian Plate (coastal marine facies) and eastern Pechora Plate (depression facies). There were traces of three isotope excursions: negative in the vicinity of the MN5 zone basement (domanic horizon basement), negative at the boundary between the MN5 and MN6 zones, and double positive excursion in the upper MN6 zone. The amplitude of excursions is usually much less in the deep-water facies. The similarity of variations in carbon isotope composition of conodont elements in geographically remote and facially different Fransnian sedimentary sequences of the northwestern Russian Plate and eastern Pechora Plate confirms the possibility of using this parameter for stratigraphic correlation. 

The results of ground-penetrating radar (GPR) studies of permafrost and aerial photography, carried out at key sites in the Sentsa River valley (Oka Plateau, Eastern Sayan Ridge), are presented.

For geophysical studies, an OKO-2 GPR completed with an AB-90 shielded antenna unit was used with a maximum sounding depth of up to 20 m and a resolution of 0.5 m. To account for the landscape elevation, the Trimble TS635 tacheometer and the Leiсa DISTO D 510 rangefinder performed hypsometric measurements with a step of 1.0 m. Aerial photography was carried out by a remotely piloted aircraft (RPA) DJI Inspire 1 Pro, equipped with a Zenmuse 3X camera (a resolution of 3840×2160 pixels) with a spatial resolution of 5.7–7.8 cm/pixel (in different years).

In the structure of frozen lacustrine-alluvial sediments, three GPR complexes are distinguished, corresponding to the active layer and frozen rocks with different amounts of schlieren, lenses and layers of texture-forming ice. The orthophoto map and tacheometric survey analysis showed that the destruction of frost mounds occurs from the second half of April to the first half of October. The most significant relief change is due to the thawing of icy pulverescent clayey silts. It leads to subsidence blocks in the ledge of the Sentsa River terrace. Lateral river thermoerosion also contributes to the frost mounds destruction.

According to the data obtained on the equipment of the IEC SB RAS complex monitoring base for hazardous geological processes "Buguldeika" (Shared Research Facilities "Geodynamics and Geochronology" of IEC SB RAS) and Shared Research Facilities "Angara" of ISTP SB RAS an analysis of the characteristics of the Kudarinsky earthquake (09.12.2020) and the behaviour of the ionosphere during this event was carried out. The source parameters of the earthquake were obtained – the seismic moment of the earthquake (M0=3.02·1017 N·m), the moment magnitude (Mw=5.6), the source radius (2.43 km), and the stress drop (1.26 MPa).

The analysis of the ionosphere behaviour carried out using GPS/GLONASS receivers did not reveal disturbances caused by the Kudarinsky earthquake, which is most likely due to the relatively small magnitude of this earthquake. An analysis of the observation series related to the Kudarinsky earthquake showed the efficiency of using the Core Facilities Centre equipment and complex monitoring bases for studying seismicity, which is the most dangerous natural process for the Baikal region.

Based on the study of the features of seismicity within the limits of continuous permafrost and in transitional climatic zones, the influence of natural and climatic factors on the magnitude of seismic impacts is revealed. The results of studies carried out to develop a regional methodology for predicting the parameters of seismic effects of strong earthquakes in the Mongolian-Siberian region during permafrost degradation are summarized. These results are based on the data of complex geophysical measurements. They are aimed at developing methods and techniques for assessing the seismic impacts of strong earthquakes on critical engineering structures located within the permafrost zone and at developing recommendations for conducting seismic micro zoning in various seismic-climatic zones of Siberia and Mongolia, taking into account potential earthquake sources.

The main goal of this study is to use the data obtained in planning and construction in seismically active permafrost areas. The developed methods and approaches are presented at the current level of requirements for the design of earthquake-resistant structures in the permafrost zone in specific areas: at the Uyanga site sum, located in Northern Mongolia, and at the Tupik site (using the example of the construction of a tailings dam), located in Russia in the Zabaykalsky Krai (Transbaikal Territory). The first section is located in the zone of insular permafrost with a probability of earthquakes of VIII-degree intensity. The second is in the area of continuous permafrost with a likelihood of VII-degree earthquakes.

The proposed and implemented integrated methodological approach makes it possible to obtain at the present level of research for the natural and predicted state of soils in the foundations of designed structures a set of seismic characteristics (accelerograms, spectra, frequency characteristics) and the main parameters of seismic effects for predicted strong earthquakes (maximum accelerations, prevailing frequencies, maxima spectra and resonant frequencies). The noted set of characteristics and parameters of seismic effects meets the modern requirements of designers. It should be accounted for earthquake-resistant structures located in various seismic-climatic zones of the Mongolian-Siberian region.

The study of the geomagnetic field evolution on minor timescales, in particular of such significant events as geomagnetic reversals and excursions, has acquired particular relevance nowadays due to the increased attention of mankind to the environment. The question of how exactly abrupt changes in the characteristics of the geomagnetic field affect the climate and biosphere remains largely debatable; the idea of the speed and dynamics of these changes is also very vague. "Classical" geological objects and existing methods provide limited opportunities for highly detailed reconstructions of geomagnetic field variations; therefore, paleomagnetologists are looking for new objects and approaches to solve this problem. The research that we have begun involves the use – for the first time in Russia – of speleothems to study secular variations of the geomagnetic field.

This brief communication presents paleomagnetic records of two drill-cores from the flowstone from Vorontsovskaya cave, located on the western flank of the Caucasus Mountains in the valley of the river Kudepsta. Preliminary results indicate the presence of a geomagnetic excursion record in both drill-cores. Further study of the samples from Vorontsovskaya cave will make it possible to compare the discovered event with known excursions, as well as to clarify its age, duration, and dynamics.

Evaluation of seismic wave attenuation parameters (Q-factor and frequency parameter) in the lithosphere of the Tien Shan and the Baikal rift was carried out using coda waves of regional earthquakes. Comparison of obtained quality factor values shows that attenuation in the lithosphere of the Tien Shan is stronger than in the Baikal rift. It can be explained by a higher level of heterogeneity of medium. 

The research provides an example of the GPS time series processing for monitoring of horizontal coseismic displacements during the 11 January 2021 M 6.7 Hovsgol earthquake, Mongolia. There has been developed a methodological approach to the study of coseismic displacements at the time of the earthquake. This paper presents the results of determining the values of horizontal coseismic displacements which are 0.6 mm in the junction zone between the Hovsgol and Tunka depressions and hundredths of a millimeter for the Siberian block and Transbaikalia areas. For stations located on the southern margin of the Siberian block and stations in Transbaikalia, the vectors of coseismic displacements are directed to the west. The calculated displacement vectors of the stations near the epicenter (MNDY and BADG) are directed to the southeast. 

In our paper we present the results of seismotomographic inversion for the local seismological monitoring data obtained in the area of the Samoylov Island (Lena River delta) in 2019–2021. Tomographic velocity model was used for refining hypocenter locations of local earthquakes and for geological interpretation. The results are shown as maps of anomalies of seismic waves and Vp /Vs ratios for the 5 and 10 km depths. The velocity anomalies structure made it possible to interpret low Vp /Vs ratio as rocks related to the Siberian platform, and to compare between the boundary of the low Vp /Vs area and the trace of the known geological fault running along the Olenekskaya Channel. 

This paper proposes a method to observe the pre-earthquake features based on the variations in ambient noises using local moderate and strong seismic events as an example. Eight earthquakes in the Baikal rift system with energy classes K=10.1–15.9 were associated to a significant decrease in the level of ambient noises at epicentral distances from 3 to 81 km a few hours before the shock. The observed decrease in the ambient noise level can be classified as a short-term precursor of the medium consolidation 4–5 hours before the earthquake.

The results of joint processing of hydrogeological and seismic data obtained at the Large-Scale Research Facilities "Mid-Latitude Geophysical Observation Complex "Mikhnevo" for a 12-year observation period are presented in the article. Responses of the "reservoir-well" system to the passage of seismic waves from distant earthquakes with magnitudes of 6.3-9.0, recorded at the epicentral distances from 1863 to 16507 km, have been identified in the database. Maximum values of groundwater level variations and ground velocity under seismic impact have been determined. The power-law dependence of the levels amplitudes of confined and weakly confined aquifers on the maximum vertical ground velocity has been established. A spectral analysis of 6-hour intervals (3 hours before and 3 hours after earthquakes) of seismic and hydrogeological data was performed. The frequencies corresponding to the maximum values of ground velocity and groundwater level variations were determined in the normalized spectra. The intervals within which the extremes of the hydrogeological responses are traced at background values of the ground velocity are identified in the low-frequency range. The amplitude-frequency characteristics of the "reservoir-well" systems differ under seismic impacts at epicentral distances up to 4901 km. The responses of the systems to earthquakes at epicentral distances of 11024-14026 km are similar.

The purpose of this work is to analyze the variations of radon volumetric activity in groundwater from the South Angara region and to identify and study the response of the emanation field to the most significant seismic events that occurred in the Baikal region in 2021. To achieve this goal, we organized daily monitoring of the radioactivity of groundwater in the study area. The analysis of the obtained series made it possible to determine the amplitude of fluctuations of radon volumetric activity Q (from 13.2 to 48.4 Bq/L), as well as the average annual (26 Bq/L) and daily average (4.5 Bq/L) indicators.

The total number of earthquakes that occurred during the year on the territory of the Baikal region yielded a sample of 40 most significant (M≥4) events, for which the radii of the areas of influence were calculated. In three cases, we found that the sampling points were located within the influence radii or close to it. In four cases, the actual distances from the monitoring points to the epicentres were one and a half to three times greater than the calculated radii, and in the rest thirty-three cases, these distances were more than three times greater than that.

Three types of emanation responses to seismic events have been identified, with one of which to be recorded before an earthquake, that is, to be a prognostic sign. Among the earthquakes demonstrating this effect, the Khubsugul earthquake was the strongest in the study area over the past ten years. Grouping by distance from the source to the sampling point relative to the radius of the event’s influence practically coincides with the set of earthquakes by the recording time and the type of recorded responses.

Thus, the fluctuations of the emanation field spread over considerable distances from the earthquake generation area with gradual attenuation, and the response recording moment and the type of anomaly that appeared on the graph depend on the power of an impending event, as well as on the distance between the earthquake epicentre and the sampling point. The study shows that the possibility of identifying the emanation precursor effects before strong earthquakes on the territory of the Baikal region is based on two primary conditions: first, sufficient strength of an impending earthquake; second, the location of the sampling point within the radius of the area of influence of this earthquake.

In April – May 2021, in the Khabarovsk Territory and Sakhalin Region in the Far East Federal District of the Russian Federation, the Federal Research Center "Geophysical Survey RAS" deployed temporary networks as a part of Large-Scale Research Facilities – continuous seismic monitoring of the Russian Federation, adjacent areas and the world. The deployment of new stations provided a reliable integration of real-time seismic data into a centralized monitoring system for the Sakhalin Region.

The seismic study has been performed in the Uglegorsk District, Sakhalin Region, where the Solntsevsky brown coal deposit – the most potential on the island – is located. There were presented the data on seismic events of different origin recorded since the stations had been brought into service. Emphasis has been placed on considerable improvements in epicenter location accuracy and enhancing possibilities of determining earthquakes and industrial explosions. There are shown the results of monitoring for earthquake mechanism studies. The monitoring system that is currently available allows recording the representative earthquake events with ML≥0.5 in the immediate vicinity of coal mines, thus providing the possibility of improving control of blasting work and of weak and potential induced seismicity caused by multiple anthropogenic impacts on subsoil.