In response to the ongoing debate on climate change and cleaner power technologies several scenarios for the future electricity generation have been recently proposed. All of them include a substantial share of photovoltaic solar technologies. However these technologies are more material intensive than traditional methods of power generation. There is a growing concern about availability of critical metals including In, Te, Se, Cd, Ge, Ga required for the large scale implementation of new technologies. These elements are companion metals recovered mainly from copper and zinc ores and bauxite. In this paper possible natural constraints on use of rare elements resulted from impact of increasing demand for companion metals on the supply of host metals are examined.

The article provides new data on the age of the tetrapod fauna “Mastodonsaurus” (Middle Triassic) of the Eastern European Platform. An analysis of the strata succession and ichnofossils has revealed that during the Eltonian time, sedimentation took place mainly in a continental environment, with occasional transgressions. In the Inderian time, there was a gradual tectonic submergence of the area — from the intertidal zone of the beach to the sublittoral zone of a brackish-water basin.

For the first time, the localities of the burrows of Lepidenteron lewesiensis polychaete worms in the Upper Cretaceous sediments of the Lower Volga region are described, and a comprehensive lithological and paleontological characteristic of the Upper Cretaceous formations of the Ulyanovsk-Saratov trough is given. Paleoecological models of paleocenosis habitats are proposed, and paleogeographic conditions for the formation of sediments containing polychaete burrows are clarified.

The development of hydrocarbon deposits is accompanied by the construction of exploration and production wells. At the same time, more than 70 % of the drilling volume falls on ecologically vulnerable areas of the cryolithozone with limited self-cleaning ability and weak protective properties.

During the disposal of drilling waste, their interaction with permafrost rocks and behavior during multiple cyclic freezing-thawing processes in the conditions of the Far North have not been sufficiently studied and remain relevant.

To assess the dynamics of changes in ion concentrations during multiple cyclic freezing-thawing processes, a chemical analysis was carried out to determine the concentration of a number of toxic metal ions, taking into account the normative indicators of the maximum permissible concentrations of elements in water (MPC). At the same time, it is shown that in some cases there is a significant decrease in the MPC of drilling waste.

The zircon is an important mineral that preserves geochemical indicators of the magmatic process and is widely used for geochronology. Recently, in addition to zircon of magmatic origin, grains of hydrothermal origin have been isolated. However, a thermodynamic description of the behavior of zirconium in postmagmatic processes has not yet been obtained. In this work, using the example of the Kivakka layered massif, the behavior of zirconium in ultramafic-mafic intrusions is considered. Zirconium, as an incoherent element, accumulates in the melt during crystallization of the massif; it crystallizes in the upper contact part of the intrusion, and then undergoes hydrothermal transformation and re-deposition in the postmagmatic process.

The issues of studying the filtration and capacitance properties of low-permeable reservoirs of the Ю2 formation of the Tyumen formation are considered to assess oil saturation in the transition zone and determine the position of the water-oil contact level in order to increase the efficiency of modeling the Ю2 formation and establish parameters for clarifying oil reserves. Significant oil deposits of the Tyumen formation have been discovered in the central part, the western, eastern and southeastern wings of the Surgut arch, which are characterized by a significant difference in well flow rates from fractions to tens of cubic meters per day. The presence of a water-oil transition zone in low-permeable reservoirs, which can account for 2/3 of the capacity of a productive reservoir, determines increased requirements for the design of a system for developing such deposits, since traditional approaches in this case are not always effective.

The study is devoted to the development of an integrated approach to determining the effectiveness of oil-acid emulsion injection activities in conditions of significant heterogeneity of productive formations. As a methodological base, well-known tools for statistical data processing were used, including the principal component method and discriminant analysis. Based on the results of constructing various models, an inverse relationship was found between the number of formation cleaning stages and the parameter reflecting the specific increase in oil flow rate per cubic meter of the agent used.

The Srednebotuobinskoye oil field has long posed a number of questions to researchers, primarily questions about the stages and conditions of formation of deposits of one of the main horizons of the Vendian period in Eastern Siberia — Botuobinsky, since it occupies a vast territory within the Nepsko-Botuobinskaya anteclise, is characterized by high productivity. Botuobinsky horizon is of strategic importance for the oil and gas industry of the Russian Federation, since the development of fields concentrated within its limits allows us to provide raw materials to the eastern regions of our country and increase its export potential in the Asia-Pacific region. The article considers the stages of formation of deposits of the Botuobinsky horizon, as well as a methodological approach based on the method of paleostructural constructions and analysis of the dynamics of structural changes.

Experimental sulfuric acid leaching of quaternary andesibasalt samples under closed system conditions under the influence of a concentrated sulfuric acid solution was carried out. A qualitative and quantitative assessment of the effect of sulfuric acid leaching on the composition and properties of andesibasalts at the first stages of opalization was carried out. The mechanism of crack formation in andesibasalts has been revealed due to the uneven expansion of the inclusions and the bulk during the leaching process. A comparison of the natural process of sulfuric acid leaching with laboratory leaching has been made.

102 samples of helvine, danalite and genthelvite from 35 objects of different genetic types, as well as two crystals of synthetic analogues of helvine and danalite, were studied. It is shown that these beryllosilicates (unlike structurally similar aluminosilicates of the sodalite-group) contain sulfur mainly in the form of S2– and in a subordinate amount in the form of the S2 •− radical anion. The nature of the Ca and Al impurities for these minerals is considered. It is assumed that the isomorphism involving Al is realized according to the scheme: 2Si4+ + S2– → 2Al3+ + ☐0 . The Ca impurity is mainly associated with calcite, fluorite and calcium garnet growths.

Three main methods for predicting effective thicknesses using seismic attributes are analyzed: linear regression based on full-wave seismic modeling data, cokriging of “attribute-well” values, neural network forecast based on a group of attributes “trained” on wells. The weathering crust in the Pre-Jurassic complex of Western Siberia was chosen as a methodological example, since with its relatively small capacity (from 0 to 50 meters) reflections from the roof and the sole are not separated. The amplitude-frequency response of this interference reflection depends on the thickness, and therefore some seismic attributes may react to this.

The analysis of independent forecast results by all three methods, their advantages and disadvantages is given. For the first time, all the basic calculations were performed using domestic software.

Assessment of the elastic properties of bottom sediments is necessary for studying the engineering-geological conditions of the investigated water area. One of the methods for obtaining the elastic properties of sediments is ultrasonic research. In June 2024, ultrasonic studies were conducted on samples of poorly consolidated bottom sediments, represented by silts and clays of various mineral compositions, in Rugozerskaya Bay of the Kandalaksha Gulf in the White Sea. Sampling was carried out using a gravity corer at 11 stations, preliminarily selected based on the analysis of seismic-acoustic profiles. A total of 25 samples (cores) were collected, with sampling depths ranging from 0.2 to 2 meters. Ultrasonic measurements of compressional and shear wave velocities were performed on 88 samples from the collected cores. The compressional wave velocity was determined based on the first arrival times at a fixed measurement base (length of the sample), while the shear wave velocity was determined using the travel-time curve of the direct shear wave on the seismogram obtained by varying the measurement base. Ultrasonic studies were conducted using piezoelectric ceramic transducers for compressional and shear waves with frequencies of 60 kHz and 100 kHz, respectively. The resulting shear wave velocities in the sediments, represented by clays and silts, ranged from 10 to 40 m/s, while compressional wave velocities ranged from 1000 to 1800 m/s.

This article presents the results of the reprocessing of the materials of the CDPM 3D seismic survey (using the common depth point method) of the combined seismic survey that is consisted of surveys of 4 separate license areas located in Western Siberia. Using the example of these materials, the importance of the role of interpretative processing control (IPC) for the purpose of improving the quality of seismic data prepared for subsequent interpretation is demonstrated in detail. IPS is the constant monitoring of changes in the quality of seismic data sequentially at each stage of processing. The constant interaction of the IPS group with processing specialists is necessary to control the quality of the performed procedures aimed at increasing the resolution of the seismic image and, as a result, improving the traceability of target objects, in particular in this article — channel objects. Frequency analysis of seismic data was used to compare the quality of paleochannels traceability in previous and new surveys. This analysis is based on RGB (red-green-blue) frequency summation. According to the results of the re-processing of 2023, significant detailing of paleochannel objects in the range of target Tyumen deposits was noted. The authors also used a specially trained neural network for searching for riverbeds, showing how much better/worse riverbed objects are traced when applying a particular processing procedure. Based on the results obtained, a consensus was formed on the acceptance or non-acceptance of the results of a particular procedure of the conducted IPS.

The article is dedicated to the factors affecting the estimation of the structural uncertainty on the 2D seismic data for the case of no LOG and VSP data on the one of the Caspian Sea areas. Complex seismogeological structure of the near-surface section and high and low-velocity local anomalies affected the structural geometry for the target reflecting horizons — are the key features of project. 2D seismic data was processed and interpreted from 2020 and 2023. During re-processing in 2023, the imaging of time and depth migrated images was significantly enhanced in particular by efficient supervision and interpretive maintenance. The results of the evaluation of the uncertainties of the structural plan for the area of interest were of fundamental importance for the further planning of the methodology of 3D seismic exploration and drilling.

The results of studying the conditions of formation of the deposits of the Northwestern Caucasus on the boundary of the Jurassic and Cretaceousare presented. The data obtained made it possible to clarified the paleoenvironments of sedimentation and the sources of erosion of clastic material. The existence of three sedimentation systems has been established: carbonate, carbonate-terrigenous and terrigenous. Paleoenvironments at the boundary of the Jurassic and Cretaceous in the Northwestern Caucasus were represented a pass from shallow-water with reef buildups on the shelve edge to relatively deep-sea marine trough environments.

The fluorine content in river and fresh groundwater of the South-Eastern White Sea area, which is the conjugation zone of the Mezen syneclise and the Baltic Shield, was determined. It was established that the studied waters are characterized by a low fluorine content, very different from the physiologically optimal range, with the exception of waters from well 27 in the Zolotitsa River valley. The level of fluorine concentrations is close to that for drinking water in adjacent territories of the Arkhangelsk Region with a different lithogenic base. This suggests the determining role of the climatic factor in the fluorine prevalence in surface and fresh groundwater in the region, which serves as current and potential sources of drinking water supply.