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We report an integrated analysis of new geological and geophysical data from the Lena River delta region to clarify the structural relationships between the Siberian Craton, the Verkhoyansk fold-and-thrust belt, and the Laptev Sea rift system. New geophysical data include the local seismic monitoring (613 earthquakes for the period of 2018-2024) and the magnetotelluric sounding measurements (MTS, 21 points). A joint interpretation of morphostructural studies, seismic tomography, MTS data, and gravity anomalies leads to the following conclusions. Seismic activity is confined to crustal structures of the Verkhoyansk fold-and-thrust belt and the South Laptev rift but has migrating character within this area. Seismic tomography reveals a two-layer crustal structure on the southwestern side of the study area. The upper layer, characterized by higher v_P / v_S ratio, corresponds to the structures of the Verkhoyansk fold-and-thrust belt overthrust onto the margin of the Siberian Craton, which are overlain by structures of the South Laptev rift. The top of the lower layer, with a lower v_P / v_S ratio, dips from southwest to northeast to depths of 15-20 km. This layer corresponds to the Precambrian crystalline basement of the Siberian Craton. This two-layer crustal model is traced beneath the deltaic sediments of the Lena River for approximately 30 km to the northeast. Further it converts into a single-layer structure with high v_P / v_S values. MTS data provide detailed information on the upper crustal structure, consistent with the presence of the South Laptev rift between the Bulkur and Bykov faults, as well as with the presence of the Tumat horst to the northeast of the Bykov fault. Modern fault activity is identified by subvertical low-resistivity anomalies from MTS data (fluid-saturated zones) and zones of earthquake hypocenter concentration from seismological data, as observed for the Bulkur, Nizhne-Lena, Bykov, and Sardakh faults.

Thermodynamic calculations have been first carried out for the entire series of lanthanides (+Y) to determine the influence of Ca in the system on the formation of rare earth (REE) mineralization during the cooling of a hydrothermal fluid from 500 to 100 °C, affecting the monazite association with a variable amount of calcite. Results show that increasing the calcite introduced into the system and raising the pH of the solution lead to significant changes in the equilibrium mineral assemblage. Increasing the initial amount of calcite in the system is followed by an increase in the stability of parisite and REE-bearing fluorite. The transition from acidic to near-neutral conditions expands the range of parisite formation with a simultaneous decrease in the amount of equilibrium bastnaesite. In acidic fluids (pH = 3 and 4), REE-bearing fluorite forms under low-temperature conditions, whereas it can be stable in the range of 400-500 °C at pH = 6.6. Under near-neutral conditions, residual unconsumed calcite occurs in the equilibrium assemblage. With an increase in calcite introduced into the system under acidic conditions, the concentration of calcium in the equilibrium fluid also rises, with a simultaneous increase in the total equilibrium concentration of lanthanides in it. In this case, calcium-enriched acidic fluids can contribute to the removal of REE, and, conversely, calcium-depleted fluids provide the deposition of lanthanides, as well as an increase in the pH of the ore-forming environment.

This study presents the results of a comprehensive assessment of mercury content in the bottom sediments of four high-altitude lakes on the Ukok Plateau (Altai, Russia): Zerlyukol’-Nur, Krasnoe, Teplyi Klyuch, and Argamdzhi. The aim was to evaluate the mercury contents and mercury fluxes in the sediments as indicators of global atmospheric pollution. The Hg content varies from 28 to 130 ppb, averaging 57.4 ± 21.4 ppb, which corresponds to background values for high-altitude lakes of the Northern Hemisphere. The elevated Hg contents in the upper core layers of three lakes reflect postindustrial contamination, whereas this trend is absent in Teplyi Klyuch, likely because of a thermal endogenous influence. Sedimentation rates of 0.18 cm/yr in Teplyi Klyuch and 0.9 cm/yr in Argamdzhi yield mercury fluxes of 3.9 and 9.1 ng/(cm²∙yr), respectively, comparable to those reported for the southern Himalayas but lower than mercury contents in industrially active regions. The obtained data indicate that the Ukok Plateau remains isolated from direct pollution sources and is significant as a background indicator area for evaluating transboundary mercury transport. This work fills a data gap on Hg distribution in remote high-altitude ecosystems and refines global mercury cycling models.

We consider the structure, depositional conditions, and subsequent development of the Koltogor-Urengoy rift system, which cuts through West Siberia in the meridional direction and has a length of 1925 km. Based on the interpretation of potential fields, the structure of the major rifts and the system of minor grabens leading to them has been defined more precisely. We have established that the Early Triassic rifting greatly influenced the geologic structure of the Mesozoic-Cenozoic sedimentary cover of the West Siberian sedimentary basin and significantly contributed to its petroleum potential. The Koltogor-Urengoy megatrough, a superorder linear depression elongated in the meridional direction and extending across the entire West Siberia, formed above the main graben-rifts of the Koltogor-Urengoy system in the structural plans of the Mesozoic reference levels. In the southern part of the basin, an active subsidence of the Koltogor-Urengoy and Tym graben-rifts in the Mesozoic and Cenozoic predetermined the occurrence of large superrift depression zones within the sedimentary succession of the Pur and Koltogor megatroughs and the Nyurolka and Tym megadepressions, which are the main oil generation zones. The positive structures of orders I and II, main zones of oil and gas accumulation, were formed above the Paleozoic basement uplifts: Severny, Nizhnevartovsk, Alexandrov, and Kaimys uplifts; and Vyngypur, Yetypur, Vasyugan, and Pudino megaswells. In the north of the basin, anticlinal traps, controlling the Aptian-Albian-Cenomanian gas accumulations, formed above the interrift blocks in the relief of the Cretaceous deposits.

The article presents the results of detailed organic geochemistry investigations being part of a comprehensive (lithological, geochemical, petrophysical) study of the Bazhenov Formation in the Tomsk Region applying the Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences methodology developed for organic matter-rich source rock. As the thermal maturity increases from PС₃ to MС₂, the content of “free micro oil” in source rock’s pore spaces has been observed to increase. In the same time, there are modifications to the composition of bitumoids (chloroform source rock extracts) from open and closed pores at both the group and molecular levels. Even “immature” organic matter has been established to show a difference in bitumoids composition from open and closed pores, which increases as it enters the main phase of oil generation (“oil window”).

The paper analyzes the data from the Yamm-Torzhok regional profile intersecting the Ilmen electrical conductivity anomaly along its major axis. This work continues the long-term research on the structure of the Precambrian basement complexes in the western part of the East European Platform conducted by the Department of Geophysics of the Faculty of Geology of Moscow State University and Geoelectromagnetic Research Center of the Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences (GEMRC IPE RAS). The obtained data combined with the analysis of the potential fields are used to construct a deep geoelectric model. Separately, a model of the structure of the sedimentary cover is presented.

The article presents data on active faulting in the Kamchatsky Peninsula (Kamchatka, Russia) located between the converging Aleutian and Kamchatka Island arcs. Convergence of the arcs leads to shortening of the Kamchatsky Peninsula, transverse to Kamchatka, and is accomplished by underthrusting of the blocks involved in the collision – of the Aleutian Arc under the Kamchatsky Peninsula and that of the Kamchatsky Peninsula under Kamchatka. It is shown that underthrusting as the way absorbing convergence is also characteristic for larger collision zones, as in case of collision of the Indian and Arabian plates with the Eurasian plate. In all the cases, the plate (block) underthrusts, in the rear of which there is a source of movements.

A complex of field geomagnetic studies is proposed, aimed at assessing the accuracy of the Earth's magnetic field models using instrumental determinations of the geomagnetic vector elements in the given location. The set of measurements consists of aeromagnetic survey using unmanned aerial vehicles, as well as ground-based measurements, including pedestrian magnetic survey and the absolute measurements of magnetic declination and inclination. The developed measurement technique allows solving the problem of determining the Earth's magnetic field in areas with insufficient coverage by stationary ground-based geomagnetic observations. The results of applying the developed technique are presented. As a case study, the territory of the central part of the West Siberian platform is chosen. The results confirm the efficiency of the proposed approach for conducting measurements over restricted time due to seasonal and weather conditions. The obtained data are highly accurate, which makes the proposed technique attractive for determining the geomagnetic secular variation in an arbitrary area.

Jamming, as well as various types of spoofing of signals from satellite navigation systems, which are currently the most effective tools in terms of positioning accuracy for moving objects, create a need to search for alternative navigation methods that ensure both accuracy and autonomy in solving the navigation problem. Among such approaches, various methods of integrating inertial navigation systems (INS) with optical navigation systems (ONS) can be highlighted, as they ensure the maximum accuracy over long intervals of motion and the minimum cost. For objects moving along arbitrary trajectories (in the absence of terrain maps and reference points), the existing methods of processing information from optical navigation systems, obtained in the form of an optical flow velocity field, enable the estimation of the current object's velocity projections - both linear and angular. However, the application of traditional methods, firstly, does not allow solving the navigation problem as a whole (determining the object's coordinates and its spatial orientation angles) and, secondly, leads to computational costs that are often critical for onboard computers. In this regard, the article considers an approach that combines the capabilities of an inertial navigation system, which provides a comprehensive solution to the autonomous navigation problem, and a developed optical observer of the object's motion parameters. This observer allows for autonomous estimation of navigation parameters without preliminary calculation of the velocity field, i.e., with the minimal computational costs. For a more complete coverage of the problem, cases of rigid camera mounting on the object, as well as its two- and three-axis stabilization, are considered. The final synthesis of algorithms for stochastic estimation of the object's motion parameters, which accounts for the uncertainty of the probabilistic characteristics of noise in a real inertial-optical navigation system, is carried out considering the possibility of subsequent application of methods from the modern nonlinear filtering theory. Due to specific features that arose during the development of the considered inertial-optical navigation system - namely, the correlation between the object and observer noises - a variant of the extended Kalman filter for correlated noises is used for stochastic estimation of the navigation parameter vector. The results of numerical modeling of the proposed navigation algorithm illustrate the possibility of its effective practical application.

This work deals with the problem of remote monitoring of forest areas in hard-to-reach places for early detection of fires. The analysis of methods and technologies of automation of this process is carried out, including the use of unmanned aerial vehicles and neural network algorithms for detecting flames and smoke on images obtained from remote operational monitoring cameras. A solution is proposed for organizing wireless communication and transmitting information to operational response centers based on a prototype of an energy-efficient ad-hoc network, which can be used under conditions of limitations imposed by terrain topography, remoteness and size of the territory, and allows for taking into account weather conditions and various geographical features of the region where video surveillance is being organized. The paper presents the results of testing both the prototype of the entire fire detection information system and the throughput of the ad-hoc network created during the research. Conclusions are drawn about the prospects for the development of the proposed hardware and software complex.