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The methods of Infrared (IR) and Raman spectroscopy, as well as gas chromatography, were used to assess the distribution, content and composition of water-containing defects in variously deformed milky-white vein quartz of the Larino deposit. Weakly deformed quartz and quartz with intensive polygonization and recrystallization, in which water is present in molecular form, in fractures, channels, intergranular space, as well as in the composition of fluid inclusions, are analyzed. The content of water-containing defects, according to IR spectroscopy and gas chromatography, decreases in a series from weakly deformed primary granular coarse-grained quartz to blocked and recrystallized. The obtained results indicate the release of water during recrystallization, along the newly formed grain boundaries by diffusion and further homogenization to achieve an equilibrium state. Gas content also depends on the degree of deformation changes in samples and decreases from large coarse-grained differences to intensely deformed quartz with a high content of recrystallized grains.

The search for oil and gas in folded zones and in the foredeep of the cis-Uralian region for many decades was reduced to drilling quite easily identified anticlinal structures and reefs located at shallow depths. Many important discoveries were made as a result, but the overall effectiveness of the work remained relatively low. On the one hand, this was due to the insufficient information content of the data for reliable preparation of structures in regions of complex structure. On the other hand, the peculiarities of the development of oil and gas systems in these regions were ignored during the assessment of prospecting sites. In comparison with traditional producing centers in the platform regions of the Volga-Ural and Timan-Pechora basins, this distinguishing feature was caused by a thicker sedimentary cover, the variability of its composition and structure, and multiple phases of structural development. Many failures were due to the formation of traps after the passage of the primary migration flow of oil and gas, low capacity of reservoirs, and their breaching by faults. As shown by interpretation of new geodata using modern knowledge about the oil and gas potential of regions of similar structure, the cis-Uralian region contains poorly studied oil and gas accumulation zones that can contain large deposits. These include blind thrust regions, subsalt traps in zones of dislocated diapirs, and also stratigraphic and combined traps associated with unconformities and facies changes. The utmost attention is paid to new prospecting objects in the Timan-Pechora basin in which the thickness of the Paleozoic cover has increased. The delineation of new promising objects in these zones has become possible due to new knowledge and better geophysical data.

Integrated seismic, drilling, and other exploration works in the southeastern Anabar-Khatanga petroleum province since the early 1930s led to discoveries of small oil and gas occurrences and one large filed of Central Olgino. However, the petroleum potential of the northwestern part of the province remains poorly investigated and evaluated. The reservoir potential appraisal is attempted in this study using all available seismic, geological, and geochemical data, including evidence from four new wells drilled in the Sopochnoe uplift and the Zhuravliny swell. The obtained data provide constraints on the extent of oil and gas generation, accumulation, and losses from degraded traps in Permian strata that have the highest potential as source rocks. The source rocks of the Upper Kozhevnikovo, Lower Kozhevnikovo, and Tustakh formations have been characterized in terms of thickness, contents of organic carbon and chloroform bitumen, maturity (catagenesis) of organic matter, and density of oil migration and gas generation. The maximum possible estimates of oil and gas resources that can potentially accumulate in structural traps, without migration losses, are obtained for each of the three reservoir formations by basin modeling. Judging by geological and geochemical criteria, the Upper Kozhevnikovo Formation can preserve only a minor portion of initially accumulated hydrocarbons, while the oil and gas accumulations, as well as the petroleum generation potential of organic matter in the Lower Kozhevnikovo and Tustakh formations, were destroyed by late Permian-Early Triassic trap magmatism and Mesozoic-Cenozoic tectonic activity.

The paper presents data on different types of Late Jurassic carbonaceous-siliceous-shale sequences of marine deposits in the western side of the Frolovskoye basin. The diverse sedimentation patterns in the area were presumably controlled by tectonics, sea bottom topography, and currents, with voluminous gas venting through large faults. Recent exploration drilling in the Elizarovo trough and the Vygnlor basin revealed Upper Jurassic sections of a previously unknown type with low-radioactivity lower strata markedly thicker at the account of biogenic radiolarite intercalations affected by postdepositional carbonatization. The lithology of these rocks is described with implications for deposition environments and extent of such sections.

To study the geological structure in the search for raw hydrocarbons within the Volga delta and the Caspian Sea, two intersecting profiles of magnetotelluric sounding were performed. The analysis of geoelectric sections based on the one-dimensional inversion of the initial and normalized invariant curves of apparent resistance showed that it is necessary to use methods of three-dimensional mathematical modeling to form reliable geoelectric models. Their initial construction necessary for the three-dimensional interpretation of invariant apparent resistance curves was carried out taking into account their one-dimensional inversion. The resulting model, including the lower structural part, is constructed by the method of interactive matching to the apparent resistance curves of model curves calculated according to the program of three-dimensional mathematical modeling. This approach made it possible to take into account the influence of local galvanic distortions on the apparent resistance curves when evaluating the distribution of electrical conductivity in the lower parts of the subsea deposits. As a result of the integrated interpretation of magnetotelluric data, blocks with increased conductivity have been identified in the subsea deposits of the Northern Caspian Sea, which are most likely associated with high fluid saturation of Cretaceous and Neogene sediments. Their position correlates with the regional discontinuous structures of the region.

Accurate assessment of mineral content and the brittleness index ( BI ) is crucial for designing effective hydraulic fracturing treatments in coal seams, a parameter required in the East Bokaro Coalfield in India. This study combines sidewall-core and well log data, focusing on well A-1, where X-ray diffraction analysis of sidewall cores was conducted to identify mineral content. The obtained mineralogical data were extrapolated to well A-2 through a synthesis of well log parameters, X-ray diffraction analysis, and prior research results. Linear regression equations incorporating known minerals and well log data as input parameters were employed to calculate volumetric mineral content in the formations. The reliability of the model was validated by assessing the minimal difference between predicted and observed log curves. Furthermore, the brittleness index was determined using both geomechanical methods based on compressional wave velocity and mineralogical methods incorporating quartz, feldspar, and dolomite content. Comparative analysis of BI values demonstrated a consistent trend, while variations in the mineralogic BI were observed in relation to mineral content. This study not only establishes a continuous multimineral model for cases with unavailable core data but also contributes to advancing the understanding of mineral content variations. Additionally, the correlation between BI variations and mineral contents enhances our knowledge of the geomechanical properties essential for design of hydraulic fracturing in coal formations. The results presented herein offer valuable insights for optimizing hydraulic fracturing strategies in the East Bokaro Coalfield and provide a foundation for further research in similar geologic settings.

A description of the designed automated complex is presented. The results of measurements of the content of species with different volatility in six particle size ranges from 0.3 to 5 μm with artificial heating from 25 °С to 100 and 200 °С are discussed. The particle concentration was recorded by an optical counter. The instrumentation complex was tested in the period 2021-2023 in separate series of round-the-clock observations in different seasons. It has been shown that variations in the relative content of soluble sulfur compounds according to the counter data are in good agreement with the variability of the values of the parameter of condensation activity. In general, we believe that the use of this method will make it possible to obtain additional information about the seasonal and diurnal variations in aerosol composition in the intermediate range of particle sizes.

The structure of the upper part of permafrost and the topographic features in the northeast of Western Siberia were shaped by changes in the natural environment in the Late Pleistocene and Holocene. In 2016-2021, sections of different landforms - ridges and thermokarst-erosional hollows - were studied within the third lacustrine-alluvial plain of the Pur-Taz interfluve. The upper part of the plain includes the Kargin-Sartan alluvial, lacustrine, and slope sediments and Holocene peatlands. Based on the stratigraphy and new geochronological data on the Pur-Taz interfluve, the consequences of the activation of neotectonic processes in the Sartan period and the influence of climatic factors on the differentiation of accumulative and denudation processes in the Holocene were identified.

This study is aimed at a preliminary analysis of ground temperature data from ten thermometric boreholes drilled and equipped by the authors in the Upper Kolyma Highland (Magadan region) in 2021-2022. The boreholes of up to 15 m in depth are located in characteristic landscapes (rocky talus, mountainous tundra, larch woodland, river valleys) of the highland at heights from 618 to 1182 m asl. Continuous monitoring of ground temperatures with a time step of 4 h was carried out. Data on the mean annual rock temperatures, seasonal thawing/freezing depths, and the depths of zero annual amplitude were obtained. The mean annual ground temperature varied from -0.1 to -3.8 °C. The depth of seasonal thawing ranged from 0.9 to 2.6 m. The depth of zero annual amplitudes was 11.5 and 13 m in two boreholes. Two boreholes located in talik zones recorded freezing depths of 2.6 and 3.6 m. Ground temperature regimes within the same region differed significantly depending on landscape conditions: elevation, landform, composition of the rock, character of vegetation, and other factors. Based on the data obtained, it is planned to further develop the geocryological monitoring network in the Magadan region. For some of the boreholes, a full annual cycle of observations on ground and air temperatures, precipitation, and snow cover depth is available. As information on the state of permafrost in the territory under consideration is virtually absent, publication of the obtained data of relatively short-term observations is relevant and timely.

A new model of pure water freezing potential (Workman-Reynolds potential) explained the positive electric charge of ice relative to water during crystallization by the fact that protons were captured faster than hydroxide ions by numerous traps of charge in ice - interstitials. In the present article, additions have been made to this model to extend its application from pure water to aqueous solutions with an impurity concentration in the parent solution of 10^-4 mol/L or more. The additions take into account the ability of impurity anions and cations to act as acceptors for protons and hydroxide ions in ice. As a result of capture by acceptors, the equilibrium concentrations of protons and hydroxide ions can shift significantly in favor of the former or the latter. This shift should radically affect the kinetics of filling the charge traps (interstitials) with protons or hydroxide ions and the sign of the electric charge of ice relative to the solution. In particular, the model explains the negative ice charge during crystallization of 10^-4 mol/L KCl solutions.