Consideration is being given to the tectonophysical approach to the reconstruction of structure formation mechanisms and stress-strain state of rocks in hydrocarbon deposits localized in the platform cover, which has a complex structure in terms of rheological layering and disturbance by different-rank fractures. With the Kovykta gas condensate field, largest in Eastern Siberia, there were shown the main methods and ways of using modern achievements in tectonophysics for interpreting geological and geophysical information on the upper and lower parts of the sedimentary cover, unique in terms of volume and significance, that was obtained during geological exploration therein. Regularities of changes in the stress-strain state of rocks, found during the research, are combined into a tectonophysical model, which can be used as a base for other hydrocarbon deposits. The model is based on the concept of a zone-block structure of the platform cover, which is formed by a network of subvertical and subhorizontal fault zones that divide it into less faulted blocks. Disjunctive structures are highly fractured zones with concentration of relatively small low-amplitude faults, i.e. represent the early stages of faulting. The zone-block structure is formed mainly by tectonic or gravitational forces; in the first case, the stages and fracture characteristics are transformed onto the platform from the surrounding mobile belts, and in the second case they are determined by the presence of ductile rocks in the section capable of gravitational sliding. The graphic component of the tectonophysical model is 3D datasets that show the zone-block structure and stress state of rocks for the deposit with the degree of detail provided by key geophysical materials and, primarily, by seismic data. By modern GIS, this information can be quickly retrieved for any-size area of the studied rock mass and then used as a basis for solving production issues related to the development of deposits in fracture-pore reservoirs, or for analyzing general problems of their formation and dynamics.

Within the Pre-Caspian sedimentary basin, there is certain regularity in the distribution of types of structures of salt tectonics. It is characterized by concentric zoning corresponding to the change in the sedimentation thickness of the evaporite sequence. As it increases from 0 to 6 km towards the center of the basin, stamp (embryonic) salt uplifts are replaced by salt pillows first and then by salt domes and diapirs, finally changing to salt massifs and amoeboid-shaped salt ridges. In addition, diapirs in the sections of the Pre-Caspian basin, drawn from the drilling and seismic data, are shaped like high-amplitude "fingers" with a flat base, which is not a typical picture of the Rayleigh – Taylor instability development. Since halokinesis is the main factor controlling the migration and accumulation of hydrocarbons in the Preaspian region, background and aim of prospecting and exploration require identifying the specifics of the formation of various types of salt structures and the relationship between their location patterns and halokinesis process.

Numerical simulation shows that, depending on the instable layer thickness and its relationship with the total thickness of the overlying layers, the instability development occurs at different rates, forming different types of structures. When the thickness of the instable layer is greater than or comparable to the thickness of the denser overburden, there occur the salt masses. A greater thickness of the overlying layer gives rise to the formation of classical mushroom-shaped diapirs. A small-thickness low-density layer first undergoes a full bending as it rises, so that its top and bottom turn out to be morphologically similar to each other, thus giving a misleading impression of ordinary stamp folds. Somewhat greater thickness of the low-density layer leads to the development of "pillows" therein. Detailed modeling made it possible to relate the specific shape of the Pre-Caspian diapirs to the fact that the basal and top horizons of the evaporite formation, being composed mainly of terrigenous, carbonate and sulfate rocks, have a normal, non-inverse density and mask complex diapiric structures of halite-saturated domal cores.

Within the Urumieh-Dokhtar Magmatic Arc in the central part of Iran, the formation of which is associated with the Neotethys closure, there are many porphyry copper deposits and ore occurrences. One of them is the Astaneh porphyry copper ore deposit, located in the central part of the Saveh-Ardestan ore region southeast of Ardestan city. The purpose of this study is to investigate the petrochemical characteristics of rocks and to determine the relationship between the distribution of porphyry copper mineralization and tectonic position of faults within the study area. To achieve the goal, there were used the structural and geological data obtained in the fieldwork, as well as the results of mineralogical and geochemical analyses. The obtained results show that rocks of different composition of the Astaneh ore deposit (andesite, andesite-basalt, basalt, trachybasalt) were formed in the suprasubduction zone, and probably in the environment prior to the collision of the of continental plates. Paragenetic relationships and mineralogical analysis show that the evolution of mineralization of the Astaneh ore deposit can be divided into three stages: pre-ore, hypogene and supergene mineralization. Geochemical research based on the study of the content of the major chemical elements in the rocks of the region shows that igneous rocks belong to calc-alkaline basalts and geodynamically can be attributed to the products of magmatism of the ensial island arc. The results concluded that the main stages of the formation of a porphyry copper ore deposit in the study area attain maximum spatio-temporal similarity with the tectonomagmatic phases of the development of the Neotethys Ocean. In addition, the Southern Ardestan fault, running through the study area and intersecting the basement structures, forms wide permeable zones favorable for the formation of porphyry copper deposits therein.

The ca 2.0 Ga Volgo-Don fold-and-thrust belt, about 500 km in width and at least 600 km in length, covering an area of about 300000 square kilometers intervenes between the Archean Sarmatian and Volgo-Uralian proto-cratonic blocks of the East European Craton, both of which are coupled with 200–300 km thick sub-continental lithospheric mantle keels. The focus of this paper is the elucidation of its nature in order to answer the basic question how this and other thrust-and-fold belts could be formed in the Paleoproterozoic, and whether they are the same as or different from modern collision orogens. The active Himalayan-Tibet orogen is commonly thought of as the most extensively studied large, bi-verging fold-and thrust belt continental collision zone which may provide insight into key tectonic mechanisms for an understanding of orogenic processes in the Earth’s geological past. Precambrian orogens are tentatively perceived yet as something that was distinct from recent orogenic styles and was due to the initial elevated geotherm and higher radio-genic heat production in the early Earth.

In this paper we report for the first time the revealation of the large, slightly eroded divergent Paleoproterozoic Volgo-Don orogen which is mostly composed of juvenile metasediments and comprises well-preserved patterns of the crustal orogenic architecture which are characteristic of the archetypal Himalayan-Tibet collisional orogen rather than of hot/ultra-hot Precambrian orogens based on numerical modeling.

U-Th-Pb isotope dating of grains of detrital zircon from quartzites of the Suvanyak metamorphic complex, which forms the Suvanyak tectonic unit that forms the western part of the Uraltau uplift, located in the east of the West Ural megazone in the Southern Urals. The results of isotope dating of grains of detrital zircon from quartzites of the southern part of the Suvanyak metamorphic complex (samples G18-1 and R14-396) show that numerous populations of Late Neoproterozoic–Early Cambrian detrital zircon grains suggest a Peri-Gondwanan origin of the primary sources of detrital material for the protolith of the studied rocks.

The structure of the Suvanyak tectonic unit involves metamorphic formations of different ages – Early Paleozoic in the south and Late Precambrian in the north, which are now formally united into a single Suvanyak metamorphic complex. Their differentiation requires additional research.

For the Late Paleozoic southeastern margin of the Baltica (at that time already involved in the structure of the composite continent Arct-Laurussia), according to the results of isotope-geochronological study of detrital zircon from the sedimentary and metasedimentary sequences of the Southern Urals, a number of the following tectonic structures were identified. Near the southeastern edge of the margin, there was a Late Neoproterozoic–Early Cambrian oceanic basin, within which a volcanic arc or arcs were active during 650–520 Ma. The structure of the southeastern edge of the margin included the Peri-Gondwanan terrane or terranes (? Cadomian type), as well as thick Riphean-Early Paleozoic sedimentary sequences, autochthonous to the Baltica.

The Bekchiul pluton is located in the Lower Amur region and is a large granitoid body of complex structure within the Zhuravlevka-Amur terrain of the Sikhote-Alin orogenic belt. On the northwestern flank of the Bekchiul pluton there is the Mnogovershinnoe gold-silver deposit. To determine the formation time of this pluton, U/Pb dating was performed on zircons from the second-phase granodiorite of the Bekchiul complex and the third-phase granite. Granodiorite yielded U-Pb age of 73.8±0.4 Ma, and granite – 66.2±0.3 Ma. Some zircon grains found in granite have a U-Pb age of 75.6±0.6 Ma which is close to that of granodiorites. Magmatic pulses of about 76–73 Ma and about 66 Ma are synchronous with the stages of ore formation of the Mnogovershinnoe deposit, corresponding to earlier-obtained K-Ar age of adularia from ore zones. The formation of granitoids and the associated mineralization probably occurred due to subduction of the Izanagi Plate beneath the continental margin.

The paper presents the first U-Pb (LA-ICP-MS) dating results for detrital zircons from the quartzsericite-chlorite schist of the Anai formation within the Baikal salient of the Siberian platform basement. During the study the detrital zircons showed a major age peak at 1.86 Ga, which indicates that the rocks of the Anai formation were accumulated after the development of magmatic rocks of the South Siberian post-collisional magmatic belt with an age of 1.88‒1.84 Ga. This fact makes it possible to reconsider a point of view on the belonging of the Anai formation to the section of the Paleoproterozoic Sarma group whose rocks were intruded by granitoids of the South Siberian magmatic belt. It is shown that the rocks of the Anai formation can be considered as age and facial equivalents of the Proterozoic sediments of the Purpol formation of the Patom zone. Taking into account the Anai formation sediments intruded by sills and dikes of the Neoproterozoic (~720 Ma) dolerites, it can be concluded that the rocks of this formation were presumably accumulated in the Early Neoproterozoic time.

There are presented the results of analysis of some irregularities in the series of displacement coordinates on the Earth’s surface for the geographic North Pole in order to relate them temporally to some global jerks in the geomagnetic field. The calculations were made using the International Earth Rotation and Reference Systems Service (IERS) data on the average daily motions of the North Pole from 1962 to 2021 and the information on global jerks in the geomagnetic field measured by the magnetic observatories throughout the world. The identification and analysis of the irregularities in the pole displacement along the Earth’s surface were performed by the Fourier Method and wavelet methods for time series analysis, methods of fixed threshold determination and minimax analysis of the non-Gaussian noise, phase and pseudo-phase space methods, and stroboscopic methods of construction of Poincare maps.

The analysis of local Fourier spectra and wavelet-spectra reveals irregularities in the displacement of the North Pole in the time intervals from 1967.04.09 to 1967.11.30, from 1974.03.29 to 1974.09.12, and from 2005.11.03 to 2006.03.07. It is supposed that energy reconstructions which caused short-term pole deviations from the trajectory and starting to follow its previous trajectory at the return points are related to the specific features of oscillatory interactions in the process of the translational-rotational motion of the Earth’s in the Solar System. The time of marking specific points on graphs of the displacement of the pole along the surface of the Earth in 1967 and 1974 is ahead of global geomagnetic jerk occurrence times.

A systematic monitoring of the hydrosphere is important and necessary to maintain a good ecological status of Lake Baikal. The article presents the results of a five-year monitoring of the groundwater and surface waters quality in Listvyanka settlement. The goal is to determine the contamination level of drinking water supply system. In the field studies, portable measurement devices were used for monitoring temperature, pH, Eh, electrical water conductivity and water levels in wells, and water samples were taken for a complete chemical analysis. The analysis of the macrocomponent composition of water was carried out by various methods (flame photometry, volumetric titration, weight method, colorimetry) at the Center for Geodynamics and Geochronology of the Institute of the Earth’s Crust SB RAS (Irkutsk); the trace element composition was determined by the ICP MS method on the Element-2 device (Finnigan MAT, Germany) at the Institute of Geochemistry SB RAS (Irkutsk); microbiological analysis of water samples was performed at the Irkutsk Interregional Veterinary Laboratory; the analysis of isotope characteristics (δ 18O and δD) of water samples was performed in the Laboratory of Hydrogeology of the Institute of the Earth’s Crust SB RAS (Irkutsk) on a Picarro L2140-i gas analyzer.

The results obtained indicate a change in macrocomponent composition of waters and an uneven distribution of pollutants over the area. The content of 42 trace elements in groundwater and river waters generally does not exceed the regulatory requirements for drinking water; the exceptions are Fe and Mn. Ten wells do not meet the sanitary and epidemiological rules and norms SanPiN 2.1.4.1074-01. The main sources of groundwater pollution are leaking septic tanks of numerous hotel complexes located in the valleys and on the valley slopes. The processes of water pollution and restoration of natural regime of water are of different intensity. For groundwater and river waters, there were determined the relative concentrations of stable isotopes of hydrogen and oxygen (δD and δ18О), and δD=5.5307·δ18 O–31.815 relationship and the deuterium excess values were obtained. Characteristics δD and δ18 O are the bases of the isotope database for the aquatic environment of Listvyanka settlement.