Terrigenous zircon of archean greenstone belts as a source of information on the early earth’s crust: Azov and Dnieper domains, Ukrainian shield

2010 ◽  
Vol 48 (9) ◽  
pp. 845-861 ◽  
Author(s):  
E. V. Bibikova ◽  
S. Claesson ◽  
A. A. Fedotova ◽  
G. V. Artemenko ◽  
L. Il’inskii
Keyword(s):  
Earth’S Crust ◽  
Ukrainian Shield ◽  
Greenstone Belts ◽  
Earth's Crust ◽  
Archean Greenstone Belts ◽  
Source Of Information

Magnetic model for the earth's crust under the Ukrainian Shield

1977 ◽  
Vol 14 (12) ◽  
pp. 2718-2728 ◽  
Author(s):  
Z. A. Krutikhovskaya ◽  
I. K. Pashkevich
Keyword(s):  
Crustal Thickness ◽  
Earth’S Crust ◽  
Ukrainian Shield ◽  
Maximum Magnetization ◽  
Average Magnetization ◽  
Magnetic Model ◽  
Regional Component ◽  
Earth's Crust ◽  
The Given ◽  
Distribution Of Magnetization

A magnetic model for the crust under the Ukrainian Shield is proposed and the following aspects of its construction are discussed: (1) technique of separation of the regional component of the anomalous magnetic field; (2) estimation of rock magnetization and distribution of the sources of anomalies within the earth's crust; (3) Modelling of the crustal effect with the given distribution of magnetization; and (4) correlation of the regional component with crustal thickness and depth to Curie point isotherm of magnetite.Two ferromagnetic layers are established within the crust. Average magnetization of the upper crust ranges from 0.1 × 10−3 to 0.6 × 10−3 emu for different blocks. Magnetization maximum for the lower crust is 4 × 10−3 emu, the value being supported by different methods.Inhomogeneities with maximum magnetization of 6.5 × 10−3 emu are found within the lower crust.In the areas of regional highs the earth's crust is the thickest, the Moho discontinuity layered, and the distribution of magnetization anomalous for all depths.The stated correlation of regional component with crustal thickness may be of value in predicting the Moho topography.

Deep reflection seismography in studying the Earth's crust of the Ukrainian Shield

1997 ◽  
Vol 269 (3-4) ◽  
pp. 269-278
Author(s):  
A.V. Chekunov ◽  
A.A. Tripolsky ◽  
O.M. Kharitonov
Keyword(s):  
Earth’S Crust ◽  
Ukrainian Shield ◽  
Earth's Crust

scholarly journals Density inhomogeneity of the earth's crust along the latitudinal zones of the faults of the Ukrainian shield and the Dnieper-Donets basin

2012 ◽  
Vol 34 (6) ◽  
pp. 113-132
Author(s):  
V. I. Starostenko ◽  
P. Ya. Kuprienko ◽  
I. B. Makarenko ◽  
O.V. Legostaeva ◽  
A.S. Savchenko
Keyword(s):  
Earth’S Crust ◽  
Ukrainian Shield ◽  
Donets Basin ◽  
Density Inhomogeneity ◽  
Earth's Crust

scholarly journals International cooperation of S. I. Subbotin Institute Geophysics, NAS of Ukraine for 2010—2020

2021 ◽  
Vol 43 (3) ◽  
pp. 205-226
Author(s):  
V. I. Starostenko ◽  
O. M. Rusakov ◽  
A. I. Yakimchik
Keyword(s):  
Antarctic Peninsula ◽  
Age Distribution ◽  
Earth’S Crust ◽  
Ukrainian Shield ◽  
Donets Basin ◽  
Mutual Position ◽  
Crust And Upper Mantle ◽  
Eastern Carpathians ◽  
Earth's Crust ◽  
The Antarctic

The geological structure of the lithosphere of the main tectonic structures has been refined for the territory of Ukraine and adjacent regions of Slovakia, Poland, Romania, Russia, as well as Bulgaria, the Antarctic Peninsula (West Antarctica) and Southeast Asia, and new data have been obtained on geophysical impacts that can affect the environment. A geodynamic scenario has been developed for the formation of large-scale folding of the Fore- Dobrudzja Trough, the South Ukrainian monocline and the Ingul block of the Ukrainian Shield, caused by tectonic events associated with the closing of the Paleotethys and Neotethys oceans in the Mesozoic. In the Pripyat-Dnieper-Donets Basin, the structure of the earth’s crust and upper mantle can reflect different intensities of rifting, from its passive stage in the Dnieper Graben to active rifting in the Pripyat Trough. An analysis of the geoelectric structure of the Earth’s crust in the Ukrainian Eastern Carpathians indicates that seismic events occur mainly in resistive solid rock domainswhich surrounded by aseismic high conductive zones consisting of at least partially melted material. The present-day mutual position of the Ukrainian shield and Fennoscandia stabilized 1720—1660 Ma. The age, distribution, orientation and composition have been studied for the LatePalaeoproterozoicdykes in the Volyn, Ingul and Azov blocks of the Ukrainian Shield. Eastern Crimea and the Sorokin Trough are fragments of a tectonic wedge formed after the Paleocene. The geothermal conditions of the Intra-Carpathian region are due to subduction during the closure of the Pannonian sea basin and the collisional interaction of the Eurasian plate with the microplates system of this region. In Bulgaria, most earthquakes occur outside high-resistive domains. The tectonic stages are reconstructed for the formation of the northern part of the Antarctic Peninsula in the Mesozoic-Cenozoic. The relationship has been established between the geomagnetic field and climate change, with it being different for the Northern and Southern Hemispheres. The results have been obtained within the framework of 25 international projects and 6 temporary international target teams of S. I. Subbotin Institute of Geophysics, NAS of Ukraine consisting of researchers from 23 countries. The results are presented in 53 publications, 38 of which are indexed in the Web of Scienct database, and 32 papers are published in 20 international journals and special publications of 10 countries with different impact factors (from 0,101 to 4,214), whose average impact factor is 3,341, and the total one is 66,815.

scholarly journals THE SPEED CHARACTERISTICS OF THE EARTH'S CRUST OF THE KOROSTEN PLUTON (UKRAINIAN SHIELD) ACCORDING TO THE DATA OF DEEP SEISMIC SOUNDING METHOD

2018 ◽  
pp. 46-50
Author(s):  
Y. Rozyhan ◽  
O. Trypilskiy ◽  
O. Topoliuk
Keyword(s):  
Short Interval ◽  
Earth’S Crust ◽  
Ukrainian Shield ◽  
Depth Interval ◽  
Basic Composition ◽  
Rate Of Increase ◽  
Seismic Sounding ◽  
Abrupt Changes ◽  
Earth's Crust ◽  
Basic Rocks

A detailed comparative analysis of the velocity characteristics of the Earth's crust of the Korosten pluton, Volyn and Chopovitsky massifs of the basic rocks of the Volyn megablock of the Ukrainian Shield was carried out. In the interval of depths of 3–13 km in the Earth's crust of the Korosten pluton, five sections are fixed, where the speed on a short interval first decreases with depth, then, on the contrary, increases. This is due to the presence in the section of a series of layers composed of rocks with reduced or elevated speeds, which alternate with increasing depth. Such changes in velocity are considered to be the results of alternation of rocks of the basic and acidic composition. With depth, the rate of increase in velocity (vertical velocity gradient), which characterizes the features of rooting into the crust of an intrusion with increased basicity, significantly decreases. These features lie in the fact that the molten masses coming from the upper mantle were concentrated mainly in the upper and middle parts of the Earth's crust. The distinction between the features of the speed characteristics of the Earth's crust of the Volynsky and Chopovitsky massifs of the main rocks is revealed. The velocity characteristics of the compared structures reflect the characteristics of the rooting of igneous melts of the basic composition into the Earth's crust. Despite the territorial proximity of the massifs, the nature of the rooting of the melts between them is significantly different. For example, abrupt changes in velocity in the depth interval of 0–12 km of the Volynsky massif can be attributed to the presence of, at least, 10 layers of rocks, predominantly of acidic and basic composition, which alternate each other. It should be emphasized that at depths of 8–12 km maximum speeds (up to 0.17–0.18 km/s) between individual layers are observed. In the same depth interval in the Chopovitsky massif, only 5 layers stand out with a maximum differential velocity of 0.18 km/s.

scholarly journals THE PALEOARCHEAN (3.3 Ga) AND MESOARCHEAN (3.0 Ga) TTGs OF THE WESTERN AZOV AREA, THE UKRAINIAN SHIELD

2021 ◽  
pp. 35-47
Author(s):  
G.V. Artemenko ◽  
L.V. Shumlyanskyy
Keyword(s):  
Chemical Composition ◽  
Detrital Zircons ◽  
Geochemical Characteristics ◽  
Ukrainian Shield ◽  
Metamorphic Rocks ◽  
The West ◽  
Siliceous Rocks ◽  
Zircon Crystallization ◽  
Greenstone Belts ◽  
Archean Greenstone Belts

A large anticline structure that includes the West Azov and Remivka blocks occurs in the western part of the Azov Domain of the Ukrainian Shield. These blocks are composed of rocks of the Mesoarchean (3.2-3.0 Ga) granite-greenstone association and relics of an older basement. The anticline is divided into two parts by the Bilotserkivka structure of sub-latitudinal strike; the northern part includes the Huliaipole and Remivka blocks, and the southern part is comprised of the Saltycha anticline. The Archean plagiogranitoids of the West Azov underwent intense dislocation metamorphism during the Paleoproterozoic. In many areas they were transformed into plagioclase gneisses that were attributed to the Paleoarchean “Kainkulak thickness” of the Azov Series. Detailed geological-structural and geochronological studies are required to define the age of these gneisses.We have chosen two areas for our studies: the Lantsevo anticline within the Bilotserkivka structure, and the Ivanivka area in the eastern part of the Saltycha anticline. The Bilotserkivka structure is composed of rocks of the Central Azov Series and highly deformed Archean formations. We have dated plagiogneisses of the Lantsevo anticline. These rocks contain large relics of metamorphic rocks of unknown age, including two-pyroxene and pyroxene crystalline schists, and pyroxenemagnetite quartzites (BIF). In terms of chemical composition, two-pyroxene crystalline schists correspond to tholeiitic basalts and basaltic komatiites. Ferruginous-siliceous rocks belong to the Algoma type typical for the Archean greenstone belts. Biotite gneisses are similar to the medium-pressure tonalite-trondhjemite-granodiorite rocks (TTGs). The U-Pb age of zircon crystallization from biotite gneisses is 3299 ± 11 Ma. At 30 km in the western part of the Bilotserkivka structure, we have previously identified quartz diorites having an age of 3297 ± 22 Ma. In terms of geochemical characteristics, they correspond to low-pressure TTGs. These data show that the Bilotserkivka structure is a block representing an ancient basement. In the Ivanivka area in the eastern part of the Saltycha anticline, the strike of the Archean rocks was reorientated from northwestern to latitudinal. The studied dislocated trondhjemites of the Ivanivka area correspond to TTGs in terms of the geochemical characteristics. They contain numerous relics of highly altered amphibolites. The U-Pb age of zircon crystallization from trondhjemite is 3013 ± 15 Ma. These rocks are of the same age as TTGs of the Shevchenko Complex cutting through the sedimentary-volcanogenic rocks of the greenstone structures of the Azov Domain. They share age and geochemical characteristics with biotite and amphibole-biotite gneisses of the “Kainkulak thickness” in Zrazkove village located at the Mokra Konka river (3.1-3.0 Ga) and with biotite gneisses in the lower reaches of the Kainkulak river (2.92 Ga). Thus, gneisses of the “Kainkulak thickness” in fact represent the Mesoarchean TTGs of the Shevchenko Complex, which were transformed in the Paleoproterozoic time due to the dislocation metamorphism. Late Paleoarchean (3.3 Ga) tonalites are known in the West Azov and the KMA domains; they probably also occur in the basement of the Middle Dnieper domains, where detrital zircons of this age have been reported. These data allow us to conclude the existence of a large Late Paleoarchean (3.3 Ga) protocraton, in which the Mesoarchean (3.2-3.0 Ga) greenstone belts and TTGs of the eastern part of the Ukrainian Shield and the KMA Domain were formed.

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