Tectonic Dislocations Research Articles

Reconstruction and validation of ground motions across dip-slip faults: an application to response analysis of a long-span suspension bridge

Recent seismic events have unequivocally highlighted the susceptibility of fault-crossing bridges to the synergistic effects of ground surface vibrations on either side of the fault plane and the tectonic dislocations arising from fault-induced surface ruptures. This study delineates both seismic and parametric response analyses of fault-crossing suspension bridges, employing a straightforward yet efficacious method for simulating desired ground motions near fault-rupture zones. Herein, we introduce a user-friendly method to incorporate predicted fault-induced displacements, accounting for both fling-step and directivity effects, into processed ground motion chronologies, enabling the generation of dip-slip fault ground motions. The accuracy and efficacy of the proposed method are affirmed by juxtaposing the generated ground motions with the observed ones (MGM). An exhaustive parametric analysis, addressing factors like fault-crossing location, fault-crossing angle, and frequency components of fault-crossing ground motions, of a suspension bridge over a rupture fault, is executed using the fashionable ANSYS software. This study provides clear and specific guidelines for the seismic design of suspension bridges traversing rupture faults.

ГЕОХИМИЧЕСКИЕ ОСОБЕННОСТИ И РУДОНОСНОСТЬ УГЛЕРОДCОДЕРЖАЩИХ ОТЛОЖЕНИЙ АМАЗАРКАНСКОГО ЗОЛОТОРУДНОГО МЕСТОРОЖДЕНИЯ (ВОСТОЧНОЕ ЗАБАЙКАЛЬЕ)

The Amazarkanskoye deposit is confined to the intersection node of the northeastern fault zone with tectonic dislocations of sublatitudinal, northwestern and submeridional directions. The Severnaya and Shirotnaya ore zones with vein-embedded stockwork-type mineralization are distinguished. Carbon-bearing sediments are represented by gneisses of the Paleo-Proterozoic Amazar Formation (AR2am), they are gravitated by zones of vein and disseminated mineralization. Gneisses are characterized by elevated gold contents from 0.05 g/t to 2.54 g/t. In terms of the organic carbon content they correspond to high carbonaceous gneisses. Shales of the Amazar Formation correspond to the terrigenous-carbonaceous formation. They were accumulated in shallow epicontinental basins or in the shelf zone in an island-arc environment. The carbon isotopic composition of graphite inclusions in quartz veins indicates its biogenic nature. It was concluded that carbonaceous gneisses of the Amazar Formation were one of the sources of gold ore mineralization.

Dynamic physical-geological model of complex folding according to paleomagnetic data

The purpose of the study is to evaluate the possibility of using the mathematical apparatus of spatial rotations to solve the determination issues of the nature and age of natural remanent magnetization vectors under complex tectonic dislocations of rocks manifested in the areas of modern folded structures of platform framing. Dynamic physical-geological models are shown to be useful when forming complex tectonic-magmatic systems. Mathematical (computer) modeling in comparison with other methods of studying geological processes features higher accuracy, cost-effectiveness and unambiguity of data interpretation in achieving the set goal. On the basis of dynamic physical-geological model of complex folding, an algorithm is developed and the results of mathematical modeling of natural remanent magnetization vectors are given for solving direct and inverse problems on correct application of the fold test under complex rock deformations. The dynamic physical-geological model of complex folded structure formation shows that the characteristic natural remanent magnetization vectors identified in laboratory experiments on demagnetization can be used to determine their age relative to the folding stages, and, depending on this, fully or partially restore the number, sequence and direction of tectonic dislocations. This will enable us to solve the mineralogenic and geodynamic problems of folded region development more effectively on the basis of paleomagnetic data.

An Approach to Detect Local Tectonic Dislocations in Coal Seams Based on Roughness Analysis

An Approach to Detect Local Tectonic Dislocations in Coal Seams Based on Roughness Analysis

SEQUENCE OF VALLEY DEVELOPMENT OF ALAKNANDA AND ITS TRIBUTATIES & QUATERNARY SEDIMENTATION, GARHWAL HIMALAYA, PARTS OF CHAMOLI TEHRI UTTAKASHI & PAURI UTTAR PRADESH (UTTRARKHAND STATE ) INDIA

SEQUENCE OF VALLEY DEVELOPMENT OF ALAKNANDA AND ITS TRIBUTATIES & QUATERNARY SEDIMENTATION, GARHWAL HIMALAYA, PARTS OF CHAMOLI TEHRI UTTAKASHI & PAURI UTTAR PRADESH (UTTRARKHAND STATE ) INDIA

Neotectonic Dislocations on the Barents Sea Shelf and Their Origin on the Basis of Morphometry of the Seafloor Relief, Seismic Survey, and the Deep Structure of the Mantle

A comprehensive analysis of the morphometric attribute “general curvature” for the Barents Sea bathymetry and reports on the seismic and seismoacoustic data on tectonic dislocations in a wave field, the fault network of the sedimentary cover, and seismotomographic data on the heterogeneous deep pattern of the distribution of seismic wave velocities in the upper mantle are provided. The analysis showed that mobile blocks of the upper mantle, exhibiting heterogeneous rheological properties, are associated with the consolidated part of the Earth’s crust fault network of deep-seated origin. The fault network emerges on the seafloor and, becoming a relief-forming factor, forms specific domains with different textures displayed in the morphometric attribute “general curvature.”

INFLUENCE OF THE TECTONIC KNOTS IN THE NORTH OF THE RUSSIAN PLATE ON THE ENVIRONMENT STATE AT THE MICROLEVEL (BY THE EXAMPLE OF THE CONTENT OF ASCORBIC ACID IN BLUBERRY AND COWBERRY FRUITS)

The study is an addition to a series of articles on the results of monitoring studies on the impact of tectonic knots on the state of the environment in the region. The knots of tectonic dislocations are a link between the abiotic (geological) and biotic environments, and have a significant impact on the state of vegetation cover, both at the macro and micro levels. This article shows the regularity of the content of ascorbic acid (vitamin C) in blueberries and cowberries, depending on their spatial location within the tectonic knot. It was revealed that the concentrations of vitamin C in berries selected in the center and on the periphery of tectonic knots differ. For example, its content in blueberries from the center of the Kholmogory tectonic knot is 37% higher than in berries from the periphery of the same knot. In the fruits of blueberries from the center of the Plesetsk tectonic knot – by 59%, and in cowberries – by 62% more, compared with the periphery. In the fruits of cowberries from the center of the Velsko-Ustyansky tectonic knot – 58% more. These knots differ from each other in geomorphometric, geological, tectonic factors, etc., which allows us to conclude that deep factors influence the state of the environment in general and the concentration of vitamin C in blueberries and cowberries in particular.

ГЕОДИНАМИКА И ИСТОРИЯ ФОРМИРОВАНИЯ ОКРАИННЫХ МОРЕЙ ЗАПАДНОЙ ЧАСТИ ТИХОГО ОКЕАНА КАК ВИХРЕВЫХ СТРУКТУР

In the tectonic structure of the Earth, formed by rotational processes, a stable regmatic network (tectonic framework) and structures of the central type (ring, vortex, etc.) are of the main importance. Lithosphere plates are global vortex systems arisen as a result of the tectonic flow of masses in the state of a viscous fluid. Eddy structures are tectonic complexes in which the results of vertical and horizontal tectonic movements combination are captured and can be recorded by direct geological observations. In the Western Pacific Ocean, it is noteworthy a series of structures in the form of a system of marginal seas representing the Western Pacific continent-ocean transition zone. The tectonic evolution of the West Pacific region is the formation of lithosphere eddies series in the continent-ocean junction zone. It is associated with the Earth mantle and upper shells (tectonospheres) energy interaction, due to the unstable regime of the planet’s rotational dynamics. Of particular interest are the global shear zones and eddies of the lithosphere formed as a result of horizontal and vertical tectonic movements combination. It is shown that: 1) all tectonic dislocations contain both horizontal and vertical components of the movement velocity, the former dominating in the structure formation of the region; 2) their interaction outcome is vortex and other nonlinear deformations of the lithosphere, which constitute the main type of structural elements of the region; 3) they are often accompanied by the tectonosphere magmatic activation in the form of convective movements and / or plumes “floating”; 4) the Western Pacific marginal-sea depressions are the funnels of convective cells, which formed lithosphere eddies under the conditions of a shift in the interacting lithosphere plates velocities.

Вивчення малоамплітудної тектоніки вугільних родовищ геофізичними методами

An analysis was made as to the usage of geological-geophysical methods for studying of low-amplitude tectonic dislocations in coal-enclosing massifs. As a result of geophysical researches conducted at coal fields, mine fields and mine workings of the Lviv-Volyn Coal Basin, the methods of field observations by means of natural electromagnetic and electric fields were worked and their results were processed for prediction and diagnostics of tectonic dislocations with a break of continuity and zones of unstressed state. To raise the efficiency of the methods of electromagnetic fields it is recommended to carry out measurements at wide frequency range (from 5 to 50 hz) with orientation of the antenna according to the world sides (azimuthal surveying) and at narrow frequency range (5; 12.5; 17 khz) with the southern orientation of the antenna (frequency sensing). According to azimuthal surveying one can calculate the vector of maximum intensity of electromagnetic radiation. It was ascertained that over distinctive dislocation one can observe the variation in the direction and absolute value of vectors. Displacement of the anomaly of electromagnetic radiation intensity at different frequency range by profile indicates the direction of dipping of the area of displacement of dislocations with a break of continuity. The method of natural electromagnetic impulse field of the Earth fixes both the dislocations, distinguishes by geological-geophysical methods before, and new low-amplitude dislocations and stressed zones.Tectonic dislocations, that are displayed only in Paleozoic deposits, are distinguished by contrast anomalies of electromagnetic radiation in electromagnetic field, but dislocations with a break of continuity that cut the Mesozoic thickness and in most cases are accompanied by zones of rock fracturing in the Cretaceous deposits: by wide destructive anomalies. Plots over worked-out lavas with stressed deformational state are characterized by strongly differential abnormal values of the intensity of natural impulse electromagnetic field of the Earth. The method of natural electric field allows us to detect zones with water-bearing fracturing rocks in the upper part of the geological section. Methods of natural impulse electromagnetic field of the Earth and natural electric field may be used both independently and in the complex with other geophysical methods for detection and tracing of tectonic dislocations and dynamically-unstressed zones. Thus, the optimum apparatus-methodical complex for detection and diagnostics of low-amplitude dislocations with a break of continuity of coal-enclosing series by electromagnetic methods (NIEMF, NEF) was formed and effective methods of field observations, processinf and interpretation of data were developed.

Forecast of hydrocarbons accumulations in the Meso-Cenozoic complex of the Black Sea-Caspian region from modeling results

As part of the analysis, it was found that in the Mesozoic, the basins under study were partly part of the Black Sea-South Caspian basin system, and at the later stages of evolution, some of them were involved in tectonic dislocations and, from the point of view of modern tectonic zoning, are partly part of the Alpine folded system. zones. The performed analysis made it possible to establish the main stages of the formation of the sedimentary section, to identify the depocenters of sedimentation on each of them and to reconstruct its evolution. As a result of the studies within the study area, four areas of stable subsidence (basin) were identified during the entire period of formation of the plate cover: Karkinitsky, Indolo-Kubansky, East Kuban and Terek-Caspian. Each of the basins is characterized by a unique evolution, which manifests itself in differences in tectonic mode, sedimentation rates. This determined the features of the geological structure of the basins - differences in the ratio of the thicknesses of the main sedimentary complexe. Keywords: sedimentary basin development analysis; Scythian-Turanian basin system; oil and gas prospecting trends; troughs; deposits; regression; sedimentation; subsidence graph.

Сейсмические исследования тектонического нарушения в зоне сочленения Кандалакшско-Двинского рифта с Архангельским выступом

The results of clarifying the deep Severodvinsk fault zone location are presented and its structure in the upper part of the section using shallow seismic survey by shear-wave reflection method and extensional reflected waves method using a system of multiple overlaps (CDP method) is considered. The site under study is located in the Kholmogorsky tectonic knot area (north of the EEP) and represents a zone of tectonic dislocation intersection. In the upper part of the section, a fracture zone was found accompanying this deep fault, in with water infiltration, discharge of reservoir gas fluids; karst was detected in carbonate rocks. This zone can be attributed to seismogenic, which implies a repetition of weak seismicity manifestation on the Arkhangelsk horst complicated by tectonic faults.

Evaluating tectonic dislocations formation under the action of stresses at the Upper Kama potassium salt deposits

Introduction. The studies of the tectonic structure, dynamic behavior and prediction of the areas of the most probable manifestation of hazardous dynamic events at the Upper Kama potassium salt deposits (VKMKS) revealed that active faults, nodal structures, fracture zones and individual fractures in the oversalt, salt and subsalt rocks exercise a decisive influence on the violation of the steady state of geological structure. The regional stress field and a large number of local factors caused by folding, basement tectonics (catagenetic and supergene leaching), exogenous (weathering and unloading) and endogenous (halokinesis) processes in the oversalt strata, the growth of dome structures, etc. cause tectonic dislocations in the VKMKS. Cracks and fissure zones have currently been incidentally mapped and quantitatively studied mainly in mine workings in the productive part of the deposit, to a lesser extent in the oversalt rock, and scarcely in subsalt deposits. A detailed high-precision gravity prospecting along with other geophysical methods is currently the only effective method for tectonic dislocations mapping in the rock mass of the VKMKS. Methods for the widespread and systematic mapping of tectonic dislocations both in plan and in section within the VKMKS have not been developed yet. However, the evaluation of kinematic tectonic dislocations development in bulk can be obtained to some extent by analyzing the qualitative and quantitative characteristics of the natural stress field. It is due to the fact that dislocations are formed only when the acting stress exceeds the limit of the corresponding longterm strength of rocks forming the object under study. Methods of research. Tectonic dislocations of various kinematic types are formed under the action of stresses. Kinematic dislocations depend on the relationships between the stress principal values. Therefore, to solve the problem of kinematic type in the Solikamsk depression (SD) and VKMKS, the data of natural stress field components measurement in Ural mine workings were analyzed, the regularities of its behavior in plan and depth were determined, which served as the basis for two mathematical models, regional and local. Research results. Mathematical modeling was carried out, giving a quantification of stress components behavior regularities with the depth for the tectonic and physical-geological conditions of SD and VKMKS. Conclusions. The data on the change in stress components, obtained from mathematical modeling for two models of the geological environment, made it possible to predict the regularities in formation of tectonic dislocations of various kinematic types at different depths in SD and VKMKS at the regional and detailed scale levels.

Geological structure of central Vietnam by interpretation processing of gravitational survey data using the “COSCAD 3D” computer technology

Background. The central regions of Vietnam are of strategic importance for the Republic, being, in fact, the gateway to the ASEAN countries. Investing in the exploration and evaluation of mineral resources, in particular ore minerals hidden at great depths, is a specific and necessary task for the country.Aim. To clarify the structural-tectonic scheme of the analysed area and to identify the main fault systems and zoning of the Central Vietnam area by the gravitational field based on classification algorithms.Materials and methods. The objectives were achieved by assessing the total gradient of the gravitational field, analysing the distribution of the field variance and the results of tracing the axes of the gravitational field anomaly. Interpretation processing of gravity data was carried out using the “COSCAD 3D” computer technology of statistical and spectral correlation data analysis.Results. The defined fault systems, which play an important role in the processes of mineral formation, have a northwestern, northeastern and latitudinal strike. The zoning of the study area according to the gravitational field, its characteristics and available geological information made it possible to identify 13 homogeneous areas. Each area is characterised by a certain level of gravitational field, the values of dispersion and total field gradient, as well as correlations between attributes. The classification results confirms the complexity of the geological structure of the area under study and the presence of three main strikes of the systems of tectonic dislocations – northwestern, northeastern and latitudinal.Conclusions. A large number of tectonic dislocations of various strikes and intensities, revealed using the methods of the probabilistic-statistical approach, implemented in the “COSCAD 3D” computer technology, indicates that the area under study is promising in terms of ore deposits.

Nickel anomalies and gold-quartz mineralization in dunite-harzburgite massifs of the Pervomaisko-Verkhoturinskaya area, Central Urals

Along with some gold-quartz deposits hosted by dunite-harzburgite massifs elsewhere in the Urals, elevated Ni concentrations were revealed within the ore field of the Anna gold-(sulfide)-quartz deposit localized in weathered oxidized dunites and harzburgites of the Pervomaisky complex (συO2p) in the Pervomaisko-Verkhoturie district of the Central Urals. The spatial association of Au and Ni concentrations in dunites-harzburgites may be attributed to a partial inheritance of Ni-controlling tectonic dislocations by those hosting gold mineralization. Therefore, the combination of halos of Ni and Au concentrations in dunite-harzburgite massifs is a favorable indicator of areas prospective for discovery of goldquartz mineralization.

Placer mineral deposits of Russian Arctic zone: Genetic prerequisites of formation and prospect of development of mineral resources

Placer deposits are an accumulation of valuable minerals both dense and resistant to weathering processes, formed by gravity separation during sedimentary processes. Placer deposits of the Russian Arctic zone (RAZ) include gold, platinum group minerals (PGM), tin, diamonds, rare metals, zircon-titanium mineral deposits and a specific type of related to placer deposits - fossil ivory. There are an insufficient number of scientific geological articles on placer deposits of RAZ in the English-language literature at present, especially of an overview nature. This review paper attempts to fill the gap and marshal on the regional scale all available data aiming to provide a framework for generating and testing new ideas on the placer deposits of RAZ. The focus is on main factors and conditions of generation of the placer deposits of industrial importance, details of key placer deposits, and perspectives of development of placer mineral resources in the region. Localization and scales of placer deposits are controlled by metallogenic, tectonic, climatic and geomorphological factors which have regional and local characters. The metallogenic factor specifies the primary sources of the placer minerals, especially for proximal (retained and partly transient) placers that have moderate transportation. Tectonics have a dual role: on the regional level it determines rate of the erosion and disintegration of the host rocks due to weathering process; while on the local level, tectonic dislocation forms structural traps of placer deposits. Climatic factor is determinative for the character of supergene processes: warm humid conditions (especially combined with stable tectonics) result in deep chemical weathering and disintegration of the host rocks containing primary mineralization which is favorable for the placer forming process; in frozen (periglacial) climate conditions, mechanical weathering processes are prevalent. Geomorphological factors are closely connected with the dynamic state of the placer forming area, from the source location to the final sedimentary accumulations. Industrial placer deposits are formed when an optimal ratio of the main factors of placer forming processes occurs. A special type of anthropogenic (technogenic) placers are formed as result of human mining activities.It is impossible to distinguish only one or two of the main universal factors which are responsible for the formation of placer deposits, as all types of placers will have one or more of these. However, the formation of placers of economic importance are always the result of an optimal combination of the metallogenic, tectonic, climatic and geomorphological factors, and the absence of even one of these may result in placers of weak or non-economic ore concentrations.As evidenced by the extensive historical mining of placer deposits and the presence of undeveloped inferred placer mineral resources, the Arctic region is a large polymineral and polygenic megaprovince with considerable placer potential.

STRUCTURAL FEATURES OF THE SOUTH-WESTERN EDGE OF THE EAST- EUROPEAN PLATFORM IN THE CONTEXT OF INTERWAR RESEARCH (1918-1939)

STRUCTURAL FEATURES OF THE SOUTH-WESTERN EDGE OF THE EAST- EUROPEAN PLATFORM IN THE CONTEXT OF INTERWAR RESEARCH (1918-1939)

Reconstruction of tectonically disrupted carbonates through quantitative microfacies analyses: an example from the Middle Triassic of Southern Italy

The main goal of the paper is the reconstruction of a Middle Triassic buildup cropping out in the central part of the Southern Apennines. Middle Triassic reefs of the western Tethys realm are well known in the Northern and Southern Alps. In contrast, few studies of the Anisian–Ladinian carbonate platforms of the southern Apennines are available, due to the diagenetic alteration and tectonic disruption that hinder their paleoenvironmental and stratigraphic reconstruction. In an attempt to fill this gap, and to improve the knowledge on the Anisian–Ladinian carbonates of central Mediterranean area, this research is focused on a carbonate buildup cropping out in the “La Cerchiara” area, Sasso di Castalda (Basilicata, Southern Italy). The buildup, affected by intense tectonic deformation associated with the development of the Apennine thrust and fold belt, was studied using a statistical evaluation of the quantitative microfacies data. The research enabled a reconstruction of the original stratigraphic relationships of the various buildup fragments. A positive linear regression between the sample positions vs the percentage of autochthonous carbonates indicates an increase of the autochthons carbonate toward the top of the succession. The allochthonous fabrics (packstone/wackestone) at the base of the section (Unit IIIa) pass gradually upward into autochthonous (boundstones) facies (Units IIIb, I), consisting of microbialites (clotted peloidal micrite, microbial-derived laminae, and aphanitic micrite), microproblematica and cyanobacterial crusts, with few encrusting skeletal organisms. Statistical data suggest that units IIIa, IIIb, and I are in stratigraphic order while unit II appears to have been moved by tectonic dislocation from its original position at the base of the succession. The absence of metazoan reef framework, and the richness of micro-encrusters, autochthonous micrite and synsedimentary cements, suggest a mud-mound style of growth for the carbonate bodies of the Southern Apennine during the Anisian.

Studies of Natural Soil Radioactivity in the Kirchhoff Hill (the Leningrad Region, the Russian Federation)

From the geoecological point of view, a special place in the geological section of the Kirchhoff Hill is occupied by highly radioactive geological bodies – dictyonema oil shales. As a result of glacial tectonic dislocations and due to numerous local elevations and depressions in the relief, dictyonema oil shales can come into direct contact with the soil over relatively large areas here. Based on the results of the route survey of the gamma field over the soils of the Kirchhoff Hill in the zone of anomalously high exposure dose rate, we laid a pit. Seven samples were taken and analyzed from the depth of 0 to 85 cm. The first two samples (0– 25 cm) correspond to the gray-humus dark-profile soil on dictyonema oil shales type. Here, the average value of the specific effective activity (Aeff) makes 1,750 Bq/kg. The average Aeff of the next 5 samples of dictyonema oil shales (25–85 cm) makes 1,870 Bq/kg. Such radioactivity values belong to the environmental hazard class IV and impose significant restrictions on building and construction in the area of studies.

ЭВОЛЮЦИЯ ПРЕДСТАВЛЕНИЙ О СТРОЕНИИ ЛОВУШЕК НЕФТИ И ГАЗА ПРИ ИЗУЧЕНИИ НЕФТЕГАЗОНОСНЫХ НЕДР НА ТЕРРИТОРИИ ЗАПАДНОЙ ЯКУТИИ

The article presents the development history of the oil and gas industry in the Republic of Sakha (Yakutia). It is shown that during the first seismic exploration, prospecting for fields was carried out exclusively in the lower reaches of the Vilyui River. These works made it possible to identify the large Khapchagai gas region in Mesozoic deposits in the eastern Vilyui syneclise and discover a number of gas fields. Traps on them are typical platform structures - brachyanticlines with first degrees of dips, without any traces of disjunctive tectonic dislocations. The latter are predicted here lower in the section, starting from the Permian top. Scientific concepts of oil and gas traps revealed in various years in Western Yakutia in the course of geological exploration, from the period of inition of the oil and gas geophysical service in the republic (1950) to the present, are considered. The evolution of concepts of the oil and gas trap structure is shown, using the example of Srednebotuobinskoye and Verkhnevilyuchanskoye fields. This evolution was carried out in the process of geological exploration due to a more complete record-keeping of disjunctive disllocations and their role in the structure of traps.

Features of rock pressure manifestations with the slice pillarless extraction of the Third potash layer at the Starobin potash salt deposit

Rock pressure manifestations in the development workings and the bottomhole region of the lower longwalls with the slice pillarless extraction of the Third potash layer of the Starobin potash salt deposit were studied. The stability of the development workings and the bottomhole space of the longwalls and the nature of interaction of the bottomhole lining with the adjoining rocks were studied. The intensity of manifestations of rock pressure in the longwalls and the nature of roof subsidence of the bottomhole region and its fall behind the face support were assessed. The nature of the loading speed distribution of the bottomhole lining for the treatment cycle was clarified. The rate of change of the loading before the heading and during this process and the loading rate of the bottomhole lining are taken as the main load support indicators for the treatment cycle. The cyclical nature of the change in the magnitude of these indicators in the interval of 10–12 treatment cycles is revealed. Their dependence on elastic stresses and creep of roof rocks after the formation of a new face is shown. The presence of the dynamic component of the load of the bottomhole lining due to the factor of the speed of the bottomhole movement was established. The influence of the deformation of rocks in the troughs of displacement on the bottomhole lining has been established. At the same time, it is shown that over a time interval of more than 2 years, the intensity of deformation of the rocks is significantly reduced. The possibility is shown how to determine the mean spacing of the secondary rock subsidence of the main roof and to identify anomalies associated with the boundaries of tectonic dislocations, faults and subsidence troughs by analyzing the dynamics of the accumulated deviations from the average of load support indicators. Recommendations have been developed on rational and safe parameters for maintaining the bottomhole region and the development workings of the lower longwalls with the slice pillarless extraction of the Third potash layer.