scholarly journals GEODYNAMICS

GEODYNAMICS ◽  
2021 ◽  
Vol 1(30)2021 (1(30)) ◽  
pp. 25-35
Author(s):  
Оleksii Bartaschuk ◽  
◽  
Vasyl Suyarko ◽  

The second part of the article studies the tectonic conditions and natural mechanisms of tectonic inversion of the Dnieper-Donets Basin and the Western Donets Graben. Method. The research uses the original method of reconstruction of fields of tectonic stresses and deformations. It also makes tectonophysical analysis of geostructures was used. The analytical base of the research consisted of the latest materials of geo-mapping, numerical modeling of deformations of the southern edge of the Eastern European platform and comparison of model and reconstructed stress fields. Results. In the geodynamic environment of the interference of the intraplate submeridional collision compression with the regional strike-slip stress field, the inversion deformations of the rift-like geostructure took place in the uplift-thrust and strike-slip modes. This led to significant horizontal movements of geomass of sedimentary rocks, deformation folding with the formation of three inversion floors - Late Hercynian (Saal-Pfalz), Early Alpine (Laramian) and Late Alpine (Attic). They formed structural ensembles of scaly tectonic covers of transverse displacement of geomass a from axial to onboard zones, folded covers of longitudinal approach from the Donbas Foldbelt and long linear anti- and synforms, the axes of which are oriented orthogonally to the direction of geomass advancement. Together they form the body of the Segment of Tectonic Wedging of geomass, which is distinguished as part of the Cover-Folded System of Tectonic Thrusting of regional scale. A feature of the tectonic framework of the Segment is the curvature of the planes of the main thrusts, which limit it, and smaller plumage thrusts, which control the folded covers of the thrust. It is associated with a change in the extension of the thrusts from the north-west in the territory of the Western Donets Graben to the western direction in the extreme south-east of the Basin. This causes the corresponding bending of the axes of the fracture anti- and synforms. Structural patterns of folding with a tendency to adapt the axes of folds to the extension of thrusts indicate significant horizontal displacements of geomas of the sedimentary stratum, which in conditions of limited geological space cause secondary deformations of linear folded forms. Due to the displacement of geomas from the zones of maximum compression in the axial part of the Graben to the zones of geodynamic shadow - in the direction of the Oryl depression and Graben boards, the West Donets Cover-Folded Tectonic Region was formed within the transition zone. Scientific novelty. The study completed an original kinematic model of tectonic inversion of the Western Donets Graben was completed. The mechanism of inversion, due to which the riftogenic structure is completely destroyed by folded deformations of platform orogeneses, is caused by the pressure of the "tectonic stamp" of the Donbas Foldbelt. Under its influence, a segment of tectonic wedge was formed in the Graben, which was diagnosed with oroclin of transverse extension of the sliding type. The body of the Oroclin is formed by echeloned, rock-articulated ensembles of anticlinal uplift -folds, synclines and scaly plates-covers of pushing. A geodynamic injection band was formed in the foreland of the Tectonic Orocline extension, where folded zones of geomas displacement were formed, which consist of coulisse articulated uplift-anticlines. At the top of the Orocline, at the ends of dynamically conjugate main thrusts, an advanced tectonic compression fan is formed. In the rear of the Oroclin – hinterland are tectonic sutures – the roots of the folding covers of the approach. Practical significance. Development of a structural-kinematic model of tectonic inversion of the Western Donets Graben will allow to improve the geodynamic model of tectonic inversion of the Dnieper-Donets paleorift, on the basis of which regional schemes of tectonic and oil-gas-geological zoning will be adjusted.

Formulation of the problem. In the second part of the article, the geodynamic mode and the kinematic mechanism of destruction of the Dnieper–Donetsk Basin by tectonic movements of the Late Hercynian and Alpine stages of tectogenesis were studied. New results of tectonophysical studies of the structural–kinematic evolution of the Earth's crust of Dnieper–Donetsk Basin at the collision stage are presented. The subject of research is a complex of deformation structures that complicate the sedimentary cover in the transitional zone of with Donetsk Foldbelt. Review of previous publications and studies. Using instrumental definitions of tectonite vergence, data of reconstruction of stress fields and quantitative modeling of deformations, a original kinematic model of tectonic inversion of the Dnieper–Donetsk Basin was developed. Methods. Structural–kinematic analysis of the structural drawings of collisional deformation and tectonics structures was used for regional geotectonic studies. Results. Tectonic inversion of the Dnieper-Donetsk Basin and Donbass began at the Late Hercynian epoch as a result of collisional movements of the compression orogen on the outskirts of the Paleotethis. Tangential compression of the southwestern direction led to the formation of gentle tectonic faults in the sedimentary cover of the Western Donets Graben, along which a lattice of thrust faults was formed. For a set of extrusion of sedimentary rocks in the reverse–thrust mode from the axial super-compressed zone, tectonic transport of geomas took place in the direction of the zones of "geodynamic shadow" on the southern side. Collisional deformations of horizons by the mechanism of longitudinal bending of the layers caused the formation of linear uplift-folding in the northern part of the Graben, and echelons of scaly thrust covers in the southern. At the Mesozoic and Cenozoic epochs, in the mode of interference of the reverse–thrust and horizontal-strike-slip fields, the Hercynian thrust lattice and the near-fault uplift folds underwent collisional deformation with the formation of coulisse–jointed folded zones and echeloned thrust covers. Based on the kinematic model of tectonic inversion of the Western Donets Graben, the geodynamics of the formation of the transition zone between the Dnieper–Donets Basin and the Donetsk Foldbelt is reconstructed. These data are the basis for adjusting the regional schemes of tectonic and oil and gas geological zoning. Scientific novelty and practical significance. The grouping of the compression axes in the western part of the Donbass caused the formation of a gorst-like geoblock-stamp, under the pressure of which the dislocated geomasses were thrusting onto the syneclisic cover of the southeastern segment of the depression. In the Western Donetsk Graben, the allochthonous stratum formed the body of the tectonic wedging geomas segment. Along the main strike–slip faults, which form the "tectonic rails" of the invasion, geodynamic zones of displacement of geomas were formed, composed of en-echelon articulated upthrust-folds. In its foreland, at the ends of the main strike–slip faults, an advanced scaly compression fan was formed, and in the hinterland, folded sutures were formed on the roots of the thrust covers. The main result of the research is a fundamentally new kinematic model of tectonic inversion of the Dnieper-Donetsk Basin. The model provides that the deformations of the riftogenic structure within the Graben were carried out according to the kinematic mechanism of the formation of a transverse orocline protruding under the pressure of the tectonic geoblock-stamp of the Donetsk Foldbelt.


GEODYNAMICS ◽  
2021 ◽  
Vol 2(31)2021 (2(31)) ◽  
pp. 53-65
Author(s):  
Оleksii Bartaschuk ◽  
◽  
Vasyl Suyarko ◽  

The article studies the system organization of inversion tectonic deformations of the Dnieper-Donetsk Basin which covered the territory of the Western Donetsk Graben. The research uses the kinematic and structural-paragenetic analysis of inversion structural transformation of the folded floors of the sedimentary cover of the Graben. The original model of tectonic inversion of the Dnieper-Donets Basin was completed from the previous models. The tectonic inversion of the Dnieper-Donets Paleorift rift-like structures began at the late Hercynian stage in the geodynamic environment of the territory of the Eastern European Platform general collision. Tectonophysical analysis shows that the inversion folding was formed by the mechanism of sedimentary horizons longitudinal bending in the environment of the interference of the intraplate submeridional collision compression and the regional strike-slip stress field. At the Mesozoic-Cenozoic stage, tectonic inversion continued in the field of right-hand strike-slip deformations with a variable compressive component. This caused the formation of folded covers of tectonic plates and scales in the uplift-thrust mode. They, Hercynian neo-autochthonous formations and further the weakly located syneclise autochthon of the South-east of the Basin. The pressure of the "tectonic stamp" geoblock of the Donetsk Foldbelt contributed to the formationof the Segment body of geomass Tectonic Wedging. It was diagnosed with a structural orocline of transverse extension of the sliding type. Large linear throw-folded zones were formed within geodynamic bands of injection and displacement of geomass along the front of the orocline. The tectonic compression fan, characteristic of geodynamic compression zones, was formed in the foreland of the orocline, on the ends of the main thrusts. They served as “tectonic rails”of the allochthon invasion within the rift-like structure. There are the transverse zones of tectonic sutures formed on the roots of the folding covers of the Hercynian neo-autochthon thrusting, which are located in the hinterland of the orocline in the Foldbelt Western slope. The study completed an original kinematic model of tectonic inversion of the transition zone between the Dnieper-Donets Basin and Donets Foldbelt. According to the model, the pressure of the “tectonic stamp” geoblock initiated the invasion of the Segment of Tectonic Wedging which consists of the intensively dislocated allochthonous geomass. The Segment destroyed the rift-like structure and formed the Western Donetsk Cover-Folded Region in the South-eastern part of the Basin. The system organization model of inversion complications of the rift-like structure in the territory of the Western Donetsk Graben will allow to improve the regional geological schemes of tectonic oil and gas zoning.


2020 ◽  
Vol 1 (182) ◽  
pp. 40-51
Author(s):  
Оleksiy BARTASHCHUK

The article concludes the trilogy on post-strip deformations of the Dnieper-Donets Basin. The results of tectonophysical analysis of collision deformations of the platform cover of the south-eastern part of the Dnieper-Donets Basin are summarized. Using the original method of reconstruction of stress and strain fields and tectonophysical analysis of geostructures, the system organization of inversion structural deformations of the Dnieper-Donets Basin and Donbass was studied. The tectonic inversion of the Dnieper-Donets Basin began in the Late Hercynian epoch in the situation of a general-plate collision under the influence of the inversion rise of the Donbas. Structural and kinematic analysis of deformations shows that the folds in the depression and linear anti- and synforms of the Donets Foldbelt were formed by the natural mechanism of longitudinal bending as a result of collisional warping of horizons in the geodynamic mode of transformation. In the late Mesozoic–­­Cenozoic inversion continued in the field of right-hand horizontal-shear deformations with a variable compressive component. This mode caused the advancing and pushing of sedimentary geomass from the Donets Foldbelt to the Hercynian neo-autochthonous and syneclise autochthonous of the South-Eastern Dnieper-Donets Basin. Due to the influence of the tectonic stamp of the Donets Foldbelt, the West Donets wedge-shaped segment was formed – the orocline of geomass tectonic wedging. Geodynamic bands of injection and displacement of sedimentary geomass were formed in the front of the invasion and in the axial zone of the orocline, where the main folded zones were formed. In Forland, at the ends of the main thrusts – “tectonic rails” of the wedging, an advanced scaly compression fan was formed. In the hinterland of the orocline, folded suture zones are formed by the roots of the covers of thrusting. The original geodynamic model of tectonic inversion provides for the destruction of the riftogenic structure in the Southeast of the Dnieper-Donets Basin by thrusting echelons of scaly covers and coulisses-articulated upliftt-folding. They compose a segment of the insertion of the geomasses of the Paleozoic cover into the territory of the West Donets Graben from the side of the Donets Foldbelt. The intrusion of the tectonic segment led to the formation of an inversion structure of a regional scale – the West Donets Cover-Folded Region.


2020 ◽  
Vol 15 (4) ◽  
Author(s):  
A.V. Bartashchuk ◽  

The tectonic inversion of the Dnieper-Donets Basin and the Donets Foldbelt began in the Late Hercynian epoch under the influence of collisional movements of the left-sided knematics of the compression orogen on the edge of the Paleotethis. It is shown that as a result of gently inclined disruptions in the Paleozoic platform cover of the West Donets Graben, a thrust lattice was formed, which controlled the processes of collisional buckling of the horizons in the thrust and strike-slip modes. As a result of the displacement of geomasses from the axial zones of maximum compression to the zones of "geodynamic shadow" - in the direction of the Basin borders in the northern and axial parts of the Graben, linear uplift folds were formed, and in the southern - thrust covers. At the Late Mesozoic and Cenozoic, in the mode of interference of the uplift-thrust and strike-slip fields of the reverse, right-sided kinematics of movements, deformations of the Hercynian thrust lattice and the dynamically conjugated linear near-fault folding took place with the formation of coulisse articulated upthrust-fold zones and en-echelonly overthrust covers. The geodynamic setting of the grouping of the compression axes in the western part of the Donbass, which was experiencing orogenic uplift, caused the thrust of allochthonous geomasses to the syneclise related autochthon of the southeastern segment of the depression. In the West Donets Graben, this caused an increase in the section beyond the Hercynian Neoautochthon and the Cimmerian-Alpine allochthon with the formation of a clinoform wedging Segment. Along the main strike-slip faults, which form the tectonic rails of its invasion, geodynamic zones of geomass squeezing out, formed by curvilinear, en-echelonly upthrow folds, were formed. In the foreland of the Segment, at the ends of dynamically coupled thrust and strike-slip faults, a forward compression fan is formed; in the hinterland, on the roots of thrust covers, folded suture zones are formed. Based on the results of the kinematic analysis of the Hercynian and Alpine deformation structures, a new kinematic model of the tectonic inversion of the riftogenic structure of the Southeastern Segment of the Dnieper-Donets Basin has been developed. In accordance with it, the deformations of the sedimentary cover of the West Donets Graben were carried out according to the kinematic mechanism of a transverse orocline of pushing geomasses of the sub-thrust type, under the pressure of the tectonic stamp of the Donets Foldbelt.


Formulation of the problem. The inversion stages of the structural-material evolution of the continental crust are characterized by regional scale of the deformation of volume tectonic flow of platform sedimentary rocks, which caused significant horizontally-healthy movements of tectonically activated geo-mass in the intra-plate graben-rift. The dynamic deformation of geomases manifests itself at the final stages of the geological development of such structures; therefore, it determines the main features of the systemic organization of the modern architecture of the basement and sedimentary cover complexes. Review of previous publications and studies. Secondary deformation linear slope, according to Patalakha E. (1979); Alekseev V. (1990) is considered as a set of local strike-slip zones, formed on spherically-located viscous faults, forming joint tectonic flows. The structural skeleton of tectonic flows, as the basis of the tectonic dislocation process, make offsets with the horizontally and rotational component movements. Horizontal landslides are typical disjunctive elements of the continental structures formed in the geodynamic conditions of the transtension (grabens, rifts), transpression (folded mobile belts, intra-plate activation zones), as well as the basic structural elements of the strike-slip tectonics of the sedimentary basin. The purpose of the article. The second part of the trilogy continues regional geotectonic studies of post-rift complications of the sedimentary cover structure of Dnipro-Donets Paleorift (DDP), covering the three main stages of the platform tectonic activation. Late Hercynian epoch was characterized by the formation of large linear anticlinal zones and salt-shafts against the background of the general syneclizal deflection of sedimentary basin, located within the paleorift. Cimmerian epoch of tectonic activity led to significant thrust deformations of the primary structural forms of the cover in the geodynamic setting of collision compression with intensification of the horizons of the sedimentary cover. The structural manifestation of strike-slip tectonics at Alpine epoch in sedimentary complexes are mainly horizontal displacements of geomases of blocks, lineaments, local tectonic elements and structures along dynamically interconnected coulisse of strike-slip domains. Methods. Structural kinematic analysis of transformations of the fracture systems of the Upper-Visean sedimentary complex under the influence of natural mechanism of reid tectonic flow of rocks. Results. The secondary structures of strike-slip deformation, structural kinematic parageneses, dislocations zones and subregional structural waves were identified in the structure of the platform cover, which are natural geological objects formed at the inversion stages of geological development of DDP. Scientific novelty and practical significance. The result of structural manifestation of volume tectonic flow in the platform complex was horizontal displacements of the original tectonic elements, blocks, segments, structures along dynamically-linked strike-slip domains. This is caused by the formation of secondary deformation structures of various scales, morphology and genesis, which comprise longitudinal structural waves of strips of post-rift deformations in the structure of the sedimentary cover of DDP.


2007 ◽  
Vol 7 (2) ◽  
pp. 45-63 ◽  
Author(s):  
Sarah L. Mander

In 2003, the UK Government adopted a target to reduce carbon emissions by 60 percent by 2050, a longer term commitment than is required under the Kyoto Protocol. Given that increasing low carbon generating capacity is essential to achieve the required carbon reductions, renewable energy policies are a central element of overall climate change policy. To facilitate the building of renewable capacity, greater responsibility has been placed upon the English regions, with the advent of regional sustainable energy strategies, though there remain many profound tensions between the liberalized UK energy system and the adoption of a more strategic approach to renewable energy at the regional scale. This paper uses a ‘discourse analysis’ framework to explore wind energy policy in the North West of England from the perspective of competing coalitions. In the light of this assessment, it is concluded that the implementation of national energy policy at regional and sub-regional scales can be considered as a process of coalition building, where Government is reliant on building partnership between state and non-state actors to achieve its objectives.


1982 ◽  
Vol 72 (2) ◽  
pp. 439-456
Author(s):  
Thorne Lay ◽  
Jeffrey W. Given ◽  
Hiroo Kanamori

Abstract The seismic moment and source orientation of the 8 November 1980 Eureka, California, earthquake (Ms = 7.2) are determined using long-period surface and body wave data obtained from the SRO, ASRO, and IDA networks. The favorable azimuthal distribution of the recording stations allows a well-constrained mechanism to be determined by a simultaneous moment tensor inversion of the Love and Rayleigh wave observations. The shallow depth of the event precludes determination of the full moment tensor, but constraining Mzx = Mzy = 0 and using a point source at 16-km depth gives a major double couple for period T = 256 sec with scalar moment M0 = 1.1 · 1027 dyne-cm and a left-lateral vertical strike-slip orientation trending N48.2°E. The choice of fault planes is made on the basis of the aftershock distribution. This solution is insensitive to the depth of the point source for depths less than 33 km. Using the moment tensor solution as a starting model, the Rayleigh and Love wave amplitude data alone are inverted in order to fine-tune the solution. This results in a slightly larger scalar moment of 1.28 · 1027 dyne-cm, but insignificant (<5°) changes in strike and dip. The rake is not well enough resolved to indicate significant variation from the pure strike-slip solution. Additional amplitude inversions of the surface waves at periods ranging from 75 to 512 sec yield a moment estimate of 1.3 ± 0.2 · 1027 dyne-cm, and a similar strike-slip fault orientation. The long-period P and SH waves recorded at SRO and ASRO stations are utilized to determine the seismic moment for 15- to 30-sec periods. A deconvolution algorithm developed by Kikuchi and Kanamori (1982) is used to determine the time function for the first 180 sec of the P and SH signals. The SH data are more stable and indicate a complex bilateral rupture with at least four subevents. The dominant first subevent has a moment of 6.4 · 1026 dyne-cm. Summing the moment of this and the next three subevents, all of which occur in the first 80 sec of rupture, yields a moment of 1.3 · 1027 dyne-cm. Thus, when the multiple source character of the body waves is taken into account, the seismic moment for the Eureka event throughout the period range 15 to 500 sec is 1.3 ± 0.2 · 1027 dyne-cm.


2015 ◽  
Vol 7 (1) ◽  
pp. 459-494
Author(s):  
L. Giambiagi ◽  
S. Spagnotto ◽  
S. M. Moreiras ◽  
G. Gómez ◽  
E. Stahlschmidt ◽  
...  

Abstract. The Cacheuta sub-basin of the Triassic Cuyo Basin is an example of rift basin inversion contemporaneous to the advance of the Andean thrust front, during the Plio-Quaternary. This basin is one of the most important sedimentary basins in a much larger Triassic NNW-trending depositional system along the southwestern margin of the Pangea supercontinent. The amount and structural style of inversion is provided in this paper by three-dimensional insights into the relationship between inversion of rift-related structures and spatial variations in late Cenozoic stress fields. The Plio-Quaternary stress field exhibits important N–S variations in the foreland area of the Southern Central Andes, between 33 and 34° S, with a southward gradually change from pure compression with σ1 and σ2 being horizontal, to a strike-slip type stress field with σ2 being vertical. We present a 3-D approach for studying the tectonic inversion of the sub-basin master fault associated with strike-slip/reverse to strike-slip faulting stress regimes. We suggest that the inversion of Triassic extensional structures, striking NNW to WNW, occurred during the Plio–Pleistocene in those areas with strike-slip/reverse to strike-slip faulting stress regime, while in the reverse faulting stress regime domain, they remain fossilized. Our example demonstrates the impact of the stress regime on the reactivation pattern along the faults.


Author(s):  
R. Alac Barut ◽  
J. Trinder ◽  
C. Rizos

On August 17<sup>th</sup> 1999, a M<sub>w</sub> 7.4 earthquake struck the city of Izmit in the north-west of Turkey. This event was one of the most devastating earthquakes of the twentieth century. The epicentre of the Izmit earthquake was on the North Anatolian Fault (NAF) which is one of the most active right-lateral strike-slip faults on earth. However, this earthquake offers an opportunity to study how strain is accommodated in an inter-segment region of a large strike slip fault. In order to determine the Izmit earthquake post-seismic effects, the authors modelled Coulomb stress changes of the aftershocks, as well as using the deformation measurement techniques of Interferometric Synthetic Aperture Radar (InSAR) and Global Navigation Satellite System (GNSS). The authors have shown that InSAR and GNSS observations over a time period of three months after the earthquake combined with Coulomb Stress Change Modelling can explain the fault zone expansion, as well as the deformation of the northern region of the NAF. It was also found that there is a strong agreement between the InSAR and GNSS results for the post-seismic phases of investigation, with differences less than 2mm, and the standard deviation of the differences is less than 1mm.


Author(s):  
Vitalij Sinika ◽  
Sergey Lysenko ◽  
Sergey Razumov ◽  
Nikolaj Telnov ◽  
Sylwia Łukasik

The article publishes and analyzes materials obtained during the study of the Scythian barrow 11 of the “Garden” group excavated in 2018 near village Glinoe, Slobodzeya district, on the left bank of the Lower Dniester, for the first time.The barrow was surrounded by a circular ditch and contained four burials – one infant and three female. The tools from the barrow are represented by knives, spindle-whorls, needle. The only piece of tableware was found and it was a wooden bowl. The adornments (a pair of earrings, two bead necklaces, one bead bracelet, two “elbow bracelets”) were also discovered. Earrings with conical bulges on one of the endings testify to the Thracian influence on the material culture of the Scythians of the North-West Black Sea region. All female graves contained mirrors. Two of them are identical, and both were laid under the body of the buried. One of the mirrors has handle aforethoughtly broken in antiquity. The cult objects are a pendant made of a dog’s tooth and a stone slab, the arrowheads are the only weapons. The barrow dates back to the second half (preferably the third quarter) of the 4th century BC. Finding a quiver set in the grave 4 of barrow 11 of Glinoe/”Garden” group made the authors to analyze the burials of the so-called Scythian “amazons” of the North Black Sea region. It turned out that many of them were attributed with flagrant violations of scientific methods as burials of women-warriors, which is nothing more than modern “myth-making”. As a result, the authors claim that an open-minded analysis allows us to distinguish three groups of Scythian burials with weapons: 1) containing weapons, placement of which reflects certain “ethnographic” features of the rite or the special status of buried; 2) containing arrowheads that may indicate hunting; 3) the burials of warriors with diverse and numerous weapons.


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