Modern Geodynamic Processes Research Articles

MODELS OF CONTEPMPORARY GEODYNAMIC PROCESSES ON THE RIM OF THE SARAJEVO DEPRESSION

<p>The rim of the Sarajevo depression was exposed to a strong construction expansion, which was not followed by spatial planning documentation. This work presents models of modern geodynamic processes, which are mainly caused by technogenic effects. The characteristics of these processes mainly depend on the morphological properties of the terrain, geological structure, engineering geological and hydrogeological properties, as well as technogenic factors. The aim of this work is to clarify the specificities of modern geodynamic processes in the areas of different lithological formations, and also to show their classification and special treatment considering process’s dynamic, the development method of the moving rock mass, causes of its movement; all with the goal of preventing or reclaiming the negative effects of these processes. The key factors that affect modern geodynamic processes are: terrain morphology, lithological structure, groundwater level, rock mass structure, as well as the technogenic processes.</p>

Influence of Modern Geodynamic Processes on the Formation of the Coastal Relief and Seabed of the White Sea

Influence of Modern Geodynamic Processes on the Formation of the Coastal Relief and Seabed of the White Sea

Geodynamic regime and prospects for oil and gas potential in the South Caspian Basin


 
 
 The article considers the geodynamic regime of the South Caspian depression, de- fines the directions of compressive stresses, the role of the latter in changing the thickness of sedimentary formation complexes, in the formation of local uplifts and their complication by faults and mud volcanism. The purpose of the study is to research the geodynamic regime and determine the oil and gas content of the South Caspian depression. The article reflects the features of studying the zone of pseudosub- duction in the South Caspian depression and the analysis of the obtained results of the prospects of oil and gas potential from the point of view of the influence of modern geodynamic processes. The study of the intensity of the formation of sedimentary facies complexes in the South Caspian depression and the features of the intensity of sedimentation allows us to distinguish 4 stages in different time intervals. According to the analysis of the available data, an inverse relationship has been established between the duration of each stage and the thickness of deposits accumulated during this period of time. In other words, the shorter the duration of the stage, the greater the thickness of the formed deposits. It was found out that this is the result of geodynamic processes occurring within the Southern Caspian Sea and in the adjacent areas, and due to the prevailing geodynamic conditions, the uncompensated deflection regime prevailing for the bottom of the South Caspian Basin had a direct impact on the process of oil and gas formation in its sedimentary cover. The depths of the boundary isotherms of catagenesis and the zone of oil and gas formation were determined in order to determine the state of each sedimentary-facies complex in the vertical zonality of oil and gas formation. It was found that in the western part of the South Caspian Basin, the lower boundary of the protocatagenesis zone is 3 km, the isotherm of the lower boundary of the oil window corresponding to 1500 C is located at a depth of 11-12 km, and the depth of the main gas formation zone corresponding to 2500 C is 18-19 km. The presented analysis of the features of oil and gas formation makes it possible to predict the formation of liquid hydrocarbon deposits at depths corresponding to the oil formation zone.
 
 

Electromagnetic Monitoring of Modern Geodynamic Processes: An Approach for Micro-Inhomogeneous Rock through Effective Parameters

This study focuses on microscale anisotropy in rock structure and texture, exploring its influence on the macro anisotropic electromagnetic parameters of the geological media, specifically electric conductivity (σ), relative permittivity (ε), and magnetic permeability (μ). The novelty of this research lies in the advancement of geophysical monitoring methods for calculating cross properties through the estimation of effective parameters—a kind of integral macroscopic characteristic of media mostly used for composite materials with inclusions. To achieve this, we approximate real geological media with layered bianisotropic media, employing the effective media approximation (EMA) averaging technique to simplify the retrieval of the effective electromagnetic parameters (e.g., apparent resistivity–inversely proportional to electrical conductivity). Additionally, we investigate the correlation between effective electromagnetic parameters and geodynamic processes, which is supported by the experimental data obtained during monitoring studies in the Tien Shan region. The observed decrease and increase in apparent electrical resistivity values of ρk over time in orthogonal azimuths leads to further ρk deviations of up to 80%. We demonstrate that transitioning to another coordinate system is equivalent to considering gradient anisotropic media. Building upon the developed method, we derive the effective electric conductivity tensor for gradient anisotropic media by modeling the process of fracturing in a rock mass. Research findings validate the concept that continuous electromagnetic monitoring can aid in identifying natural geodynamic disasters based on variations in integral macroscopic parameters such as electrical conductivity. The geodynamic processes are closely related to seismicity and stress regimes with provided constraints. Therefore, disasters such as earthquakes are damaging and seismically hazardous.

The joint seismic-and-electromagnetic monitoring with electromagnetic field separation

The magnetotelluric soundings (MTS) are a common tool in applied geophysics. The guidelines for electromagnetic (EM) monitoring should be updated because of new tools and software developed. Some techniques paragraphs have outdated sections. Some essential equipment requirements and its’ allowable parameters, MTS acquisition, are defined. We involve Research Station RAS patents (RU 175972 U1, 2017; RU 2701876 C1, 2018) to increase the long-term stability of electrical parameters of non-polarizable electrodes. We consider the irreversible rock deformations form sources of the electromagnetic field of endogenous origin as geodynamic processes. We offer MTS with an additional algorithm with electromagnetic field separation for studying the endogenous component of EM field as a lower half-space impedance. We explain the technology of MTS in seismically active zones with remote access on the example of the Tien Shan. We introduce these guidelines acquiring data system for the joint seismic-and-electromagnetic monitoring for the modern geodynamic processes. We show a result diagram for the energy characteristic of the endogenous component of EM field.

Geophysical monitoring of the geodynamic regime of Central Armenia

Geophysical monitoring of the geodynamic regime of the territory of Armenia is carried out including observations of the chemical composition of groundwater, changes in the stress-strained state of the earth’s crust and current seismicity. Hydrogeochemical effects of changing the stress-strained state of the medium as indicators of modern geodynamic processes have been revealed. Based on published data, the authors suggest that the nature of the manifestation of geochemical anomalies depends on the parameters of the forthcoming seismic event – magnitude (M) and epicentral distance (Δ). A map of the spatial-temporal distribution of deformations of the earth’s crust because of earthquakes over the past three years in the region has been compiled. The main components of ionic (Cl–, HCO3, SO4, Mg2 +, total mineralization) and gas (CO2) composition of mineral waters in comparison with seismicity in the earth’s crust are studied. A map of the distribution of earthquake epicenters in space and in time has been compiled. The obtained graph shows the hypocenters dependence of magnitude of earthquakes that occurred during the investigated period on the depth of hypocenters. Earthquake catalogue is using to plot earthquake recurrence. Statistical analysis of observational data showed that the most informative predictive characteristic is the dispersion of carbon dioxide content in water. According to the time series of concentrations of chemical indicators, the effects associated with the geodynamic regime of the earth’s crust of Central Armenia were determined. A map of the distribution of deformations in the earth’s crust of central Armenia was compiling taking into account the depths of the hypocenters of earthquakes.

Геодинамические GNSS наблюдения на Курильских островах

The network of geodynamic GNSS observations was deployed in 2006 throughout the Kuril island arc from Japan to Kamchatka. The network includes 11 stations of continuous and periodic registration. The article provides information on the organization of the network and its current status. The creation of the GNSS network provided extensive material for studying the modern geodynamic processes in the Kuril segment of the subduction zone of the North American (Okhotsk) and Pacific lithospheric plates. The performed observations made it possible to obtain the first information on the modern geodynamics of the region. The article presents an overview of the results of the previous years obtained by the authors together with other researchers. The source models of the largest seismic events are constructed on the basis of the instrumental data: the 2006 Mw 8.3 and 2007 Mw 8.1 Simushir earthquake doublet and the 2013 Mw 8.3 deep-focus Okhotsk earthquake. At the initial stage of the post-seismic process in the epicentral zone of the Simushir earthquakes, the dependence of the asthenosphere viscosity on the observed post-seismic displacement velocity of the Earth’s surface was found. The results obtained earlier were supplemented by new data on the changes in the geodynamic setting in the subduction zone. The dynamics of the transient decaying post-seismic process in the central part of the island arc is studied. Stress relaxation in the Earth’s crust at various stages of this process could be the trigger of powerful volcanic eruptions occurred in 2009–2019 on the central Kuril Islands. The seismic potential of various segments of the Kuril subduction zone has been clarified on the basis of the modeling of current mechanical coupling of lithospheric plates. It contributes to a more accurate assessment of the seismic hazard of the region together with other methods. The continuation of the GNSS observations on the Kuril Islands in the future will allow us to study in detail the features of the modern geodynamics of the region.

Ways to improve the reliability of interpreting the results of geophysical surveys performed for the local forecast and prospecting for solid minerals: a geodynamic approach

Background. The geodynamic approach is effectively used in regional forecasting and prospecting works. However, its application for local forecasting and prospecting for solid minerals is limited and sometimes impossible. One of the key problems of local forecasting and prospecting for minerals (solid, liquid, gaseous) is the presence of non-standard (flickering) geophysical anomalies, which complicates the interpretation of the results of geophysical surveys performed at different times at different stages of geological exploration. The article is devoted to clarifying the possibility of using geodynamic research in local forecasting and prospecting for solid minerals on the basis of attracting the latest scientific knowledge from the field of studying the spatio-temporal patterns of the development of modern geodynamic processes and their influence on the Earth’s geophysical fields. Aim. To increase the reliability of interpreting the results of geophysical surveys performed for local forecasting and prospecting for solid minerals.Materials and methods. The research was carried out on the basis of a comprehensive analysis of literature data, fund materials and the results of many years of the author’s own research in the fields of modern geodynamics and prospecting and exploration geodynamics. The initial data were based on the monitoring data of various Earth’s geophysical fields (deformation, seismic, and surface magnetic).Results. A geodynamic reason for the appearance of flickering anomalies in the Earth’s geophysical fields (in particular, magnetic) has been established, and a mechanism for their formation under the influence of modern geodynamic processes has been proposed. The possibility of using the geodynamic approach in the prospecting for solid minerals has been expanded, and ways to increasing the efficiency of local searches have been proposed.Conclusions. The research demonstrates the possibility of using geodynamic studies in local prospecting for solid minerals, which helps to increase the reliability of the results of interpretation of geophysical survey data, and, as a result, to reduce the overall financial and time costs involved with searching for mineral deposits.

Modern problems and prospects for the development of magnetotelluric monitoring on the territory of the Bishkek geodynamic test site

The high sensitivity of the electromagnetic parameters of the geological environment to the influence of geodynamic processes for the territory of the Bishkek geodynamic test site is shown. An assessment of the characteristics of the stress-strain state of the geological environment and the behavior of variations in electromagnetic parameters has been carried out in order to identify patterns in their relationship for seismically active regions of the Tien Shan. The promising objects for monitoring observations are identified and the results obtained are presented. The experimental results obtained indicate that the position of the regions of stable correlation (clusters) on the polar correlation diagrams is associated with the geoelectric structure of the observation point and corresponds to the orientation of the main tectonic elements in the vicinity of this point. A detailed geological and geophysical interpretation of geoelectric sections was carried out in order to separate modern active faults and weakened zones of the Earth’s crust, for example, the Kochkor basin. The relationship between the manifestation of geoelectric inhomogeneities and the spatial distribution of the epicenters of seismic events is revealed; it is shown that a significant part of earthquake epicenters is confined to structural inhomogeneities of the Earth’s crust; the depths of the geoelectric section, most sensitive to the influence of geodynamic processes, have been determined. The behavior of variations in the electrical conductivity of the earth‘s crust in a wide range of periods has been investigated according to the data of profile magnetotelluric soundings (MTS) at the Kentor geophysical monitoring minipolygon. Field experiments confirm the concept of the relationship between the stress-strain state of the medium and the change in apparent resistivity through the redistribution of saline solutions between fracture systems. The problems and trends in the development of magnetotelluric monitoring of modern geodynamic processes in the Northern Tien Shan are shown. To solve the tasks set, a methodology for conducting monitoring studies is proposed, which most fully takes into account the specific features of the deep structure and distribution of seismicity of the Bishkek geodynamic test site.

Broadband Measuring Complex with Pseudonoise Signals for Electromagnetic Monitoring of Modern Geodynamic Processes in Seismically Active Zones

Broadband Measuring Complex with Pseudonoise Signals for Electromagnetic Monitoring of Modern Geodynamic Processes in Seismically Active Zones

Influence of modern geodynamic processes on the structure and tectonics of the Black Sea-Caspian Region

The article considers the monitoring results of long-term geodynamic observations, on the basis of which the concentration areas of elastic stresses and strains in the depositional sequence, displacement of geodetic coordinates of on the Earth’s surface, as well as the variations in electric and magnetic fields are studied. The authors analyzed the results of the magnetometric studies to identify the seismomagnetic effect and assessed the stress–strain behavior of seismogenic areas. To observe the changes in the Earth’s surface due to geodynamic processes, we used high-precision GPS measurements carried out using the differential method and the so-called GPS base stations. From the comparison of earthquake parameters and based on the geological model of the sedimentary cover with regard to the seismic data of the common depth point (CDP) method, we conclude that the earthquakes recorded in the Black Sea–Caspian region in 2006–2010 occurred on the border between the Mesozoic and Cenozoic levels and within the Cenozoic interval of the geological section. Degassing monitoring based on the geophysical observatories of mud volcanoes indicates that the gas regime and degassing in the region are closely related to the impact of modern geodynamics on the evolution of the surface and deep shells of the Earth, as well as on the accumulation of combustible minerals. The studies were supported by the Ministry of Science and Higher Education of the Russian Federation under State Contract No. 075-00069-20-01 (the basic part of the state contract in the field of scientific activity).

MODERN GEODYNSMIC PROCESSES, POTENTIAL FIELDS AND COAL CONTENT OF THE NORTHWESTERN PART OF SALAIR

One of the possible methods for assessing modern geodynamic processes in the development of the earth's surface relief is described. It is based on the analysis of the exogenously active layer. Within its limits, the relief-forming process is studied as a result of the interaction of endogenous and exogenous forces, which occurs under the influence of neotectonic movements. As a result of modeling within the research object, the correspondence of the latest movements and formations was established not only of the Carboniferous-Permian coal-bearing basin, confirmed by gravimetric data, but also of the Permian-Triassic volcano-plutonic province.

Modern Geodynamic Processes and Their Impact on Replenishment of Hydrocarbon Resources in the Black Sea–Caspian Region

Modern Geodynamic Processes and Their Impact on Replenishment of Hydrocarbon Resources in the Black Sea–Caspian Region

ОПЫТ ТАМПОНИРОВАНИЯ ШАХТНОГО СТВОЛА В УСЛОВИЯХ ПРОЯВЛЕНИЯ СОВРЕМЕННОЙ ГЕОДИНАМИЧЕСКОЙ АКТИВНОСТИ

The paper presents the results of studying of the effectiveness of water pressure in the shaft of a mine with the use of grouting are presented. The enclosing rock massif is character-ized by simple hydrogeological conditions and moderate manifestation of modern geodynamic activity. Despite the significant volume of the performed backfill measures, the expected result was not obtained due to the underestimation of modern geodynamic processes when choosing the backfill materials. In the conditions of a geodynamically active rock mass, the plugging ma-terial must retain plasticity throughout the entire period of operation.

A model of the deep structure of the Earth’s crust and upper mantle in the area of the Karymshinsky gold-ore cluster according to geophysical data (South Kamchatka)

In the South of Kamchatka, modern geodynamic processes are actively taking place. A deep geological and geophysical model of the structure of the Earth’s crust and upper mantle along the regional profile of the Apacha Village-Mutnaya Bay in the zone of Tolmachevsky active magmatic center is presented. The profile passes near the South-Western border of the Karymshinskaya volcano-tectonic structure (VTS) and crosses the Ahomtenskaya VTS. The model created on the basis of integrated interpretation of materials of the earthquake converted-wave method (ECWM), gravity and magnetotelluric sounding (MTS). The thickness of the Earth’s crust along the profile varies from 30-33 km at the edges reaching 44-46 km, in its central part. The dominant feature of the model is a high-density formation – a block of the Earth’s crust, saturated with intrusions of the main and ultrabasic composition. The formation of the block is associated with a permeable zone between the crust and the upper mantle. In the block correlation of seismic boundaries is disturbed and in a density model the area with massive heterogeneity is allocated. A significant increase in depth to the M-Boundary in the center of the model is explained by the presence of a “bloated” transition layer between bark and mantle in this place. The thickness of the layer is about 10 km, and the density of the mantle reaches 3.4 g/cm3. It is assumed that this is a site of eklogization of breeds in a zone of paleosubduction of oceanic lithosphere under a continental. The area is favorable for the accumulation of meteor waters, which are in contact with high-temperature environment and postmagmatic solutions of intrusions, which leads to the formation of hydrothermal systems. The genetic connection of Karymshinsky gold-ore cluster with the intrusive array of medium-sour composition, allocated in the zone of the Tolmachevsky active Magmatic Center is shown.

Geodynamics of Central Armenia Based on the Results of Hydrogeochemical Monitoring

Method for geophysical monitoring of the earth's crust has been introduced since 2000 aiming to study the earth's crust of Central Armenia. The method allows to track modern geodynamic processes of the region. The nature of time-space distribution of hydrogeodeformation processes of Central Armenia has been studied. The nature of space-time distribution of geodynamic intensity is determined. Anomalies of components of chemical composition of water have been recorded on stress-strain areas of Earth's crust. Types of seismotectonic deformation have been determined. The present work introduces the hydrogeochemical method of studying the geodynamic processes of the Earth's crust of Armenia. The method is based on hydrogeochemical observations of the chemical composition of mineral waters and their comparison with seismicity. The objective of the hydro geochemical method is to identify hydrogeochemical effects which mainly occur in the changes of macro-component and gas composition of waters related to geodynamic movements of the Earth's crust. The results of the applicaiton of the hydrogeochemical method in the central part of the region, confirmed the connection of the parameters of seismic events variations with the chemical composition of groundwater, as well as carbon dioxide (СО₂) dissolved in water. Stressed areas of the Earth's crust are observed according to the anomalies of components of chemical composition of water. Types of seismotectonic deformation are determined. Geochemical anomalies are most clearly observed in the macro-component composition of mineral water and gases. Seismic events are preceded by geochemical anomalies of components of water composition in relation to background values in percentage ratio. The hydrogeochemical method, combined with other methods, can serve as a reliable precursor to earthquakes and other geodynamic processes of the Earth's crust. The role of the hydrogeochemical method is also effective for short-term and operational prediction of tectonic movements of the Earth's crust (earthquakes, in particular).

Determination of stress in the geological medium on the basis of well data using acoustoelastic correlations

A method has been developed to determine normal components of the stress tensor in deformed geological media on the basis of geophysical well logging. The theoretical basis of the method is the acoustic correlations of the non-classical linearized approach of nonlinear elastodynamics. Analytical formulae are obtained to calculate the stress in the geological medium in cases of small and large deformations. Geophysical well logging data located in the South Caspian basin have been used. Thin-layered one-dimensional models of the medium have been compiled on velocities of pressure and shear waves, density and lithology of rocks. The thickness of each layer of the model is several centimeters, which is equal to the observations in the well. The data of each model related to the same rock lithology is divided into clusters using artificial neural networks to consider the influence of changes of thermobaric conditions of the geological medium on acoustic properties of rocks. Values of elasticity moduli of the second and third orders and components of normal stress tensor have been calculated according to models for each lithology of rocks and a cluster of data. It has been revealed that elasticity moduli of the third order are much more sensitive to the variability of elastic properties of the medium than moduli of the second order. The obtained numerical results on all clusters of each lithology of rocks are averaged. At the same time, the number of medium layers on each data cluster has been used as weights. The number of medium layers in each rock has been used as weights while averaging the results for all the rocks. The correlations between numerical values of normal components of stress tensor caused by geostatic pressure and similar values caused by geodynamic changes of stress tensor have been studied. It has been revealed that values of stress bulk caused by geostatic pressure are significantly lower than stress caused by geodynamic changes. The obtained acoustic formulae allow determining values of stress in the geological medium of any region considering the influence of modern geodynamic processes.

ИЗУЧЕНИЕ НЕОБРАТИМЫХ ДЕФОРМАЦИЙ В ЛИТОСФЕРЕ ТЯНЬ-ШАНЯ ПО МАГНИТОТЕЛЛУРИЧЕСКИМ ДАННЫМ (МЕТОДОЛОГИЧЕСКИЙ АСПЕКТ)

Based on the field depth magnetotelluric measurements performed in the Tien Shan region, examples of the extraction of an electromagnetic field of endogenous origin are considered. The research was based on the following working hypothesis: irreversible rock deformations (cracking (and)) caused by the development of modern geodynamic processes form sources of the electromagnetic field of endogenous origin. The authors have introduced an approach that suggests the electromagnetic field of endogenous origin to be included in the impedance relations in an additive manner, which allows us to separate the electromagnetic field recorded on the surface, according to the position of the sources. The main point of this algorithm is that the known impedance of the lower half-space requires finding the difference between the tangential components of the electromagnetic field registered on the day surface. To implement the algorithm, a data processing programme for magnetotelluric sensing was compiled in order to identify sources of electromagnetic fields of endogenous origin.

Birth and death of oceanic basins: geodynamic processes from rifting to continental collision in Mediterranean and circum-Mediterranean orogens

The study of the evolution of ocean basins from birth to death is crucial for the understanding of the geodynamic evolution of orogenic systems. Exhumed ophiolite-bearing orogenic belts represent significant fossil analogues of different types of modern oceanic basins, allowing detailed multiscale and multidisciplinary investigations. Such investigations are highly important to our understanding of the ancient and modern geodynamic processes connected to the different stages of complete tectonic evolution, from rifting to subduction, collision and exhumation.

On connection of modern geodynamic processes in carbonate rocks with tectonic activization of Petrivs’k-Kreminna fault

The given paper considers the connection of modern geodynamic processes in carbonate rocks with the tectonic activation of Petrivs’k-Kreminna fault. It is emphasized that faults in the region are the channels of the upward heat and mass transfer.The unloading of deep formation waters and endogenous fluids in the area Petrivs’k-Kreminna and other faults results from heat and mass transfer, which is brought about by the motions of lithospheric blocks of Donets’k folded structure.The present tense dynamic state of the geological system manifests itself in the constant uplifting of the hanging wings of Svyatohirs’k brachyanticline at a speed of 1,3-2,5 mm a year. Earthquakes with the focal depth of ~10 km are associated with periodic geodynamic stress relaxation in the Archean-Proterozoic basement complex in the ancient geologically closed submeridional fault that intersects within Svyatohirs’k structure with the Petrivs’k-Kreminna fault. The modern and most recent tectonic activation of the latter is evidenced in the formation of hypogenic hydrogeochemical anomalies, accompanied by hydrochemical inversion. The groundwater here exhibit alkaline reaction (pH up to 8,2), an increased temperature (19- 27 °C) in the range of 0-300 m and a high content of hypogenic trace elements, among which carbon dioxide takes pride of place.The presence of CO2 increases the aggressiveness of underground water towards carbonate rocks, resulting in a chemical geodynamic process referred to as karst. Furthermore, abnormal physical and chemical properties of groundwater bring about suffusion processes in loamy, chalk strata of rocks. These geodynamic processes are associated with geological risks for buildings of Svyatohirs’k monastery.The study found that: 1) the tectonic activation of the Petrivs’k-Kreminna fault in various and, above all, the modern and contemporary periods of Alpine tectonogenesis is the dominant energy basis of geodynamic processes, including seismic activity; 2) carbon dioxide as atmospheric and deep genesis present in the groundwater of different types, is the major factor in the development of carbonate karst in Svyatohirs’k brachyanticline; 3) the isotopic analysis of δ13C and δ18O in aragonite chalk powder clearly showed that recrystallization of chalk into aragonite occurred involving deep formation waters saturated with endogenous (metamorphogenic or mantle) CO2.