The structural framework and recent geodynamics of the Greater Caucasus Meganticlinorium in the light of new data on its deep structure

Рогожин, Е. А.; Горбатиков, А. В.; Stepanova, M. Yu.; Ovsyuchenko, А. N.; Андреева, Н. В.; Kharazova, Yu. V.

doi:10.1134/s0016852115020053

Cited by 25 publications

(14 citation statements)

References 10 publications

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“…Where regional studies identify the trace of the MCT, generally without supporting field data, there is considerable inconsistency. In the Kazbegi region of Georgia (Figure ), several early studies place the MCT along the Adaykom‐Kazbek (or Adaykomskiy) fault, which broadly juxtaposes the crystalline Gveleti and Dariali massifs to the north against Caucasus Basin strata to the south (Leonov, ; Shempelev, ), whereas other studies place the MCT on the Tiba fault ~20 km to the south (e.g., Rogozhin et al, ; Vincent et al, ). Likewise, the location of the MCT is also disputed within the Caucasus Basin strata in eastern Greater Caucasus, with some authors placing it within the main range (e.g., Mosar et al, ; Vincent et al, ) and others on the Zangi fault farther to the south, at a major structural juxtaposition of differing Cretaceous facies (Cowgill et al, ; Forte et al, ; Khain et al, ; Kopp & Shcherba, ).…”

Section: Tectonic Settingmentioning

confidence: 99%

“…The nomenclature of the MCT has also been extended to refer to an inferred Cenozoic basal décollement that is assumed to be the principal structure at depth accommodating Arabia‐Eurasia convergence in the Greater Caucasus (e.g., Philip et al, ; Reilinger et al, ; Shempelev, ; Shempelev et al, ). Profiles across the range reveal a shift in crustal velocities within the upper ~10–20 km of the crust from higher velocities in the north to lower velocities in the south that has been tentatively interpreted as representing a crustal‐scale décollement at depth, but the depth resolution of these profiles is insufficient to delineate the fault geometry clearly (e.g., Pavlenkova, ; Rogozhin et al, ; Shempelev, ; Shempelev et al, ). The correspondence of this inferred active décollement with the exposed shear zone observed within the range is generally implied by the shared name, but a correlation between these two structures has not been established.…”

Section: Introductionmentioning

confidence: 99%

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Evolution of the Greater Caucasus Basement and Formation of the Main Caucasus Thrust, Georgia

et al. 2020

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Along the northern margin of the Arabia-Eurasia collision zone in the western Greater Caucasus, the Main Caucasus Thrust (MCT) juxtaposes Paleozoic crystalline basement to the north against Mesozoic metasedimentary and volcaniclastic rocks to the south. The MCT is commonly assumed to be the trace of an active plate-boundary scale structure that accommodates Arabia-Eurasia convergence, but field data supporting this interpretation are equivocal. Here we investigate the deformation history of the rocks juxtaposed across the MCT in Georgia using field observations, microstructural analysis, U-Pb and 40 Ar/ 39 Ar geochronology, and 40 Ar/ 39 Ar and (U-Th)/He thermochronology. Zircon U-Pb analyses show that Greater Caucasus crystalline rocks formed in the Early Paleozoic on the margin of Gondwana. Low-pressure/temperature amphibolite-facies metamorphism of these metasedimentary rocks and associated plutonism likely took place during Carboniferous accretion onto the Laurussian margin, as indicated by igneous and metamorphic zircon U-Pb ages of~330-310 Ma. 40 Ar/ 39 Ar ages of~190-135 Ma from muscovite in a greenschist-facies shear zone indicate that the MCT likely developed during Mesozoic inversion and/or rifting of the Caucasus Basin. A Mesozoic 40 Ar/ 39 Ar biotite age with release spectra indicating partial resetting and Cenozoic (<40 Ma) apatite and zircon (U-Th)/He ages imply at least~5-8 km of Greater Caucasus basement exhumation since~10 Ma in response to Arabia-Eurasia collision. Cenozoic reactivation of the MCT may have accommodated a fraction of this exhumation. However, Cenozoic zircon (U-Th)/He ages in both the hanging wall and footwall of the MCT require partitioning a substantial component of this deformation onto structures to the south. Plain Language Summary Collisions between continents cause deformation of the Earth's crustand the uplift of large mountain ranges like the Himalayas. Large faults often form to accommodate this deformation and may help bring rocks once buried at great depths up to the surface of the Earth. The Greater Caucasus Mountains form the northernmost part of a zone of deformation due to the ongoing collision between the Arabian and Eurasian continents. The Main Caucasus Thrust (MCT) is a fault juxtaposing old igneous and metamorphic (crystalline) rocks against younger rocks that has often been assumed to be a major means of accommodating Arabia-Eurasia collision. This study examines the history of rocks along the MCT with a combination of field work, study of microscopic deformation in rocks, and dating of rock formation and cooling. The crystalline rocks were added to the margins of present-day Eurasia about 330-310 million years ago, and the MCT first formed about 190-135 million years ago. The MCT is likely at most one of many structures accommodating present-day Arabia-Eurasia collision.

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Section: Tectonic Settingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Evolution of the Greater Caucasus Basement and Formation of the Main Caucasus Thrust, Georgia

et al. 2020

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“…It is a complex system of alpine folded structures with the latest active tectonic movements. The modern structure, geodynamics, and seismicity of the Caucasus region are determined by submeridional contraction associated with the continuing convergence of the African-Arabian and Eurasian plates of the lithosphere [Rogozhin et al, 2000].…”

Section: Caucasus Regionmentioning

confidence: 99%

“…Along this zone, seismic activity is noted. The northern slope is smoother and it is also limited by the zone of deep faults very active in contemporary times, which is manifested in increased seismicity [Rogozhin et al, 2000].…”

Section: Caucasus Regionmentioning

confidence: 99%

“…The Central segment occupies the highest position, and the other two stepwise submergence from it to the sides of the Azov-Black Sea and Caspian depressions [Khain and Limonov, 2004;Milanovsky, 1968]. Transverse disturbances in the structure of the Greater Caucasus, as a rule, are high-amplitude faults, often having a shear component [Rogozhin et al, 2000].…”

Section: Caucasus Regionmentioning

confidence: 99%

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Strong earthquake-prone areas recognition based on the algorithm with a single pure training class. II. Caucasus, {\itshape {M}} $ \geq $ 6.0. Variable EPA method

Дзебоев¹,

Soloviev²,

Dzeranov³

et al. 2019

Russ. J. Earth Sci.

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Strong earthquake-prone areas recognition (≥ 6.0) in the Caucasus is performed by means of the new "Barrier-3" pattern recognition algorithm. The obtained result is compared with potentially high seismicity zones recognized previously using the "Cora-3" pattern recognition algorithm. It is proposed to define an interpretation of the integral recognition result by the "Barrier-3" and "Cora-3" algorithms as a fuzzy set of recognition objects in the vicinity of which strong earthquakes may occur in the Caucasus.

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Study of the tension of a heterogeneous hydroelastic system

Zaretskaya

2021

IOP Conf. Ser.: Mater. Sci. Eng.

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The purpose of the article is to analyze seismic-acoustic wave fields and stress-strain state in a complex heterogeneous seismogenic structure of the contact area of the continental and oceanic crust, taking into account two types of impact: technogenic and pressure of the oceanic water column. The study uses the theory of block structures and the block element method, developed on the basis of a topological approach. It is shown that the contact stress can be considered as a superposition of stress waves occurring at the interface between the liquid and elastic media. The number of waves, their amplitude and frequency are determined by the physical and geometric characteristics of the volume of the liquid, the elastic semi-bounded layer, the elastic foundation, as well as the oscillation frequency of the external harmonic load. The model can be useful in the design of a transport network, production facilities on the coastal territory, since it allows one to assess seismic risks before the start of the process, as well as the risks of associated hazardous exogenous phenomena - landslides, tsunamis, and volcanism activation.

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The structural framework and recent geodynamics of the Greater Caucasus Meganticlinorium in the light of new data on its deep structure

Cited by 25 publications

References 10 publications

Evolution of the Greater Caucasus Basement and Formation of the Main Caucasus Thrust, Georgia

Evolution of the Greater Caucasus Basement and Formation of the Main Caucasus Thrust, Georgia

Strong earthquake-prone areas recognition based on the algorithm with a single pure training class. II. Caucasus, {\itshape {M}} $ \geq $ 6.0. Variable EPA method

Study of the tension of a heterogeneous hydroelastic system

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