scholarly journals Geology, physical-chemical and geodynamic conditions for the formation of Sokolovsk and Krasnokamensk granitoid massifs (South Ural)

Georesursy ◽  
2021 ◽  
Vol 23 (1) ◽  
pp. 85-93
Author(s):  
Vladimir I. Snachev ◽  
Aleksandr V. Snachev ◽  
Boris A. Puzhakov
Keyword(s):  
Early Carboniferous ◽  
Southern Urals ◽  
Geological Structure ◽  
Rift System ◽  
Second Phase ◽  
The Southern Urals ◽  
Lower Carboniferous ◽  
Sedimentary Deposits ◽  
Granite Formation ◽  
Physical Chemical

The article describes the geological structure of the Sokolovsk and Krasnokamensk massifs located in the central part of the Western subzone of the Chelyabinsk-Adamovka zone of the Southern Urals. They are of Lower Carboniferous age and break through the volcanogenic-sedimentary deposits of the Krasnokamensk (D3kr) and Bulatovo (S1-D1bl) strata. It was found that these intrusions belong to the gabbro-syenite complex and are composed of gabbroids (phase I) and syenites, quartz monzonites, less often monzodiorites (phase II). The rocks of the second phase predominate (90–95%). Gabbros belong to the normal alkaline series of the sodium series and are close to tholeiitic mafic rocks, the formation of which is associated with riftogenic structures; syenites correspond to moderately alkaline series with K-Na type of alkalinity. It has been proved that in terms of their petrographic, petrochemical, geochemical, and metallogenic features (content of TiO2, K2O, Na2O, Rb, Sr, distribution of REE, the presence of skarn-magnetic mineralization), the rocks of the massifs under consideration undoubtedly belong to the gabbro-granite formation. Crystallization of the Sokolovsk and Krasnokamensk intrusions occurred at a temperature of 880–930 °С in the mesoabyssal zone at a depth of about 7–8 km (P = 2.2–2.4 kbar). At the postmagmatic stage, the transformation parameters of the initially igneous rocks were, respectively, T = 730–770 °C, P = 4.0–4.2 kbar. The fact that these massifs belong to the gabbro-granite formation makes it possible to include them, together with Bolshakovsk, Klyuchevsky, Kurtmaksky and Kambulatovo, into the Chelyabinsk-Adamovka segment of the South Ural Early Carboniferous rift system.

History of the formation of the early Carboniferous gabbro-granite formation, Southern and Middle Urals

2019 ◽  
pp. 10-18
Author(s):  
A. V. Snachev ◽  
V. I. Snachev ◽  
M. A. Romanovskaya
Keyword(s):  
Early Carboniferous ◽  
Southern Urals ◽  
Island Arc ◽  
Middle Urals ◽  
The South ◽  
The Southern Urals ◽  
Granite Formation ◽  
History Of

The article presents new data on the geology and petrogeochemistry of the Magnitogorsk, Nepljuevsk and Kanzafarov rock complexes. Their belonging to the gabbro-granite formation has been proved. These data give opportunity to combine the South Ural and Middle Ural segments of the Early Carboniferous subduction rift into a single submeridional structure. Its formation took place at the Devonian island arc rear basin. The arc was overthrusted on the western edge of the East Ural Rise during the collision stage of the Southern Urals development. The Cu-Mo specialization of granitoids of the Magnitogorsk and Nepljuevsk complexes has been established.

New genus of Cyclida (Crustacea) from Lower Carboniferous (Mississippian, Viséan) of Russia and England and new species from Viséan of Russia

2019 ◽  
Vol 294 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Eduard V. Mychko ◽  
Rodney M. Feldmann ◽  
Carrie E. Schweitzer ◽  
Alexander S. Alekseev
Keyword(s):  
New Species ◽  
New Genus ◽  
Unique Feature ◽  
Southern Urals ◽  
The Southern Urals ◽  
Lower Carboniferous ◽  
Reef Environments

Within the crustacean group Cyclida, Prolatcyclus gen. nov. includes two species, Prolatcyclus martinensis (Goldring, 1967) and P. kindzadza sp. nov., described from the Lower Carboniferous (Mississippian, upper Viséan) of England and the Southern Urals of Russia, respectively. Members of the genus have a unique feature for cyclids – large hypertrophied second axial lobes. The species P. kindzadza is 2.5 times larger than P. martinensis. Both species are exclusively inhabitants of reef environments.

scholarly journals Geological structure and petrology of the Nizhne-Sinyachikhinsky granitoid massif (Alapayevsk-Sukhoi Log porphyry copper zone, the Middle Urals)

LITOSFERA ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 212-223
Author(s):  
S. V. Pribavkin ◽  
A. V. Коrovko ◽  
I. A. Gottman
Keyword(s):  
Inductively Coupled Plasma ◽  
Porphyry Copper ◽  
Southern Urals ◽  
Geological Structure ◽  
Main Phase ◽  
Middle Urals ◽  
The Southern Urals ◽  
Rock Composition ◽  
Inductively Coupled ◽  
Intermediate Chamber

Research subject. The geological structure and rock composition of the Nizhne-Sinyachikhinsky plagiogranite massif, which is part of the Alapaevsk-Sukholozhsky zone, is promising for the Cu(Au,Mo)-porphyric mineralization type, were studied. The aim was to determine the formation features of these rocks and compare them with the productive granitoids of Ural porphyry deposits of similar age. Materials and methods. The mineral composition of the rocks was determined using a JEOL JSM 6790LV scanning electron microscope with an INCA Energy 450 X-Max 80 EDS spectrometer and a CAMECA SX-100 electron microprobe analyser. The rock composition was obtained by X-ray fluorescence spectrometry on a SRM-35 and XRF-1800 spectrometers with the titrimetric determination of FeO. The concentrations of rare and rare-earth elements were determined on an ELAN 9000 inductively coupled plasma mass spectrometer at the Geoanalitik Center for Collective Use of the Ural Branch of the Russian Academy of Sciences. Results. For the first time, an early tonalite-plagiogranite series was identified in the structure of the massif. This series is represented by tonalites of the hypabyssal appearance, broken through by the dikes of plagiogranite-porphyry. It was shown that the separation of plagiogranite-porphyry melts from magmas of the mafic composition occurred at the base of the island-arc construction, and their crystallisation was carried out in an intermediate chamber at a pressure of 1.8–2.3 kbar. In contrast, the plagiogranites of the main phase of the massif were separated from the parent melt in an intermediate chamber located at the level of the upper crust, and their crystallisation occurred at a pressure of 1.5–2.0 kbar. Conclusions. A comparison of the main phase plagiogranites and the isolated early-series plagiogranite-porphyry indicates their similar composition, as well as their similarity in age with the granitoids of the Southern Urals, productive in terms of the porphyry mineralisation type. The concentrations of F, Cl and S in the apatites and amphiboles of the rocks under study is an argument in favour of their belonging to andesitoid formations that are productive in terms of the Cu (Au)-porphyry mineralisation type. The absence of the sulphide mineralisation of this type can be explained by a more significant depth of rock formation and their erosion section.

scholarly journals GOLD-JASPEROID MINERALIZATION IN ZONE OF THE SHARTYMSKIY FAULT (SOUTH URALS)

2020 ◽  
Vol 19 (3) ◽  
pp. 275-281
Author(s):  
P. V. Kazakov ◽  
Keyword(s):  
Southern Urals ◽  
South Urals ◽  
Weathering Crust ◽  
The Southern Urals ◽  
Lower Carboniferous ◽  
Stage Of Development ◽  
Deposit Type ◽  
Economic Concentration ◽  
Carboniferous Limestone ◽  
Gold Bearing

The Shartymskiy Graben was formed at zone of the Shartymskiy Fault in the late collision stage of development of the Southern Urals on the joint of the Western and Eastern Magnitogorsk sub-zone in conditions of variable compression and stretching, and was made with the Lower Carboniferous limestone. Occurrences of gold-bearing metasomatites (jasperoids, sericite-chlorite-carbonate-quartz, sericite-quartz) have been established in the precontact zones of carbonates, gabbro-dolerites, diorites dykes, and small intrusions of sub-alkaline leuсograniteporphirs of the Shartymskiy massif. Mediated connection with them of gold sprouts is established. The gold economic concentration of the Vorontsovskiy deposit type is expected on the certain sections of metasomatites of jasperoid association and their weathering crust.

The Choice of Nationality Policy in Bashkiria, 1917–1925

2017 ◽  
Vol 44 (1) ◽  
pp. 47-67
Author(s):  
Alexey Novozhilov
Keyword(s):  
Southern Urals ◽  
Second Phase ◽  
Power Structures ◽  
The Southern Urals ◽  
Nationality Policy ◽  
Elite Level ◽  
Self Rule ◽  
Education Culture ◽  
Governing Institutions ◽  
Significant Attention

Several factors shaped nationality policy in Bashkiria in 1917–25: involvement of the central Bolshevik and regional White governments and activities of Muslim and Turko-Tatar elites, but Bashkir elites’ activism proved most significant. At first (1917–19) a long-range approach to practical organizational steps predominated. National activists in this period proceeded mainly on the higher elite level, proclaiming their principles and organizing national governing institutions; at the lower level they only disseminated propaganda of their views. In the second phase (1919–25), with Soviet power established in the Southern Urals a crucial struggle occurred concerning forms of national autonomy for Bashkiria and significant attention was paid to extending nationality policy to lower administrative levels. The main forms of struggle to achieve national autonomy’s objectives were convening congresses of deputies, forming assorted power structures based upon the congresses, establishing contacts with various governments but mainly with the Bolshevik government in Moscow, creating a national military, and struggling against alternative governments in Ufa and Orenburg. The major results of nationality policy in Bashkiria in 1917–25 can be summarized thus: legal formalization of the territorial integrity of a Bashkir autonomous entity and its relations with the federal center; inclusion of factory agglomerations in the autonomous region; granting of broad autonomous powers in education, culture, direct self-rule, and matters of justice; and creating conditions for development of all spheres of life involving the Bashkir language. Finally, the successes of indigenization policy and activity toward formation of a national intelligentsia are noteworthy.

Volcanism of the transitional stage from the Late Devonian island arc to Early Carboniferous rifts in the Southern Urals

2008 ◽  
Vol 63 (6) ◽  
pp. 359-367 ◽  
Author(s):  
N. V. Pravikova ◽  
E. A. Matveeva ◽  
Al. V. Tevelev ◽  
A. B. Veimarn ◽  
A. V. Rudakova
Keyword(s):  
Early Carboniferous ◽  
Southern Urals ◽  
Island Arc ◽  
Late Devonian ◽  
Transitional Stage ◽  
The Southern Urals

scholarly journals Latitudes of the Eastern Ural microcontinent and Magnitogorsk island arc in the Paleozoic Ural Ocean

LITOSFERA ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 842-850
Author(s):  
V. S. Burtman ◽  
A. V. Dvorova ◽  
S. G. Samygin
Keyword(s):  
Middle Devonian ◽  
Volcanic Belt ◽  
Early Carboniferous ◽  
Southern Urals ◽  
Island Arc ◽  
Middle Urals ◽  
The Southern Urals ◽  
Tectonic Zone ◽  
Middle Ordovician ◽  
The Baltic

Research subject. Rocks of the Paleozoic Eastern Ural microcontinent and Magnitogorsk island arc occupy a significant part of the Southern Urals and some part of the Middle Urals. The Western Urals are composed of rocks of the ancient Baltic continent and overthrust oceanic rocks. In the Eastern Urals and Trans-Urals rocks of the accretion complexes, oceanic crust, island arcs, the Eastern Ural microcontinent and the Kazakhstan Paleozoic continent are widespread. Rocks are exposed in the Denisov tectonic zone. The Magnitogorsk simatic Island Arc originated in the Ural Ocean, near the Baltic continent, in the early Devonian, developing from the Emsian to the Famennian. A collision between the Magnitogorsk arc and the Baltic continent occurred in the Famennian century. In the pre-Carboniferous age, the Eastern Ural microcontinent was located in the Ural Ocean. In the Tournaisian period, the Eastern Ural microcontinent accreted with the Baltic continent. The Kazakhstan continental massif was located on the other side of the Ural Ocean. The volcanic belt above the subduction zone was active on the edge of the Kazakhstan continent in the Early–Middle Devonian and in the Early Carboniferous. A subduction under the Baltic and Kazakhstan continents consumed most of the crust of the Ural Ocean by the middle of the Bashkir century. As a result, the Baltic continent (together with the Eastern Ural microcontinent) came into contact with the Kazakhstan continent. The formation of folded orogen began in the Moscow century following the collision of sialic terrains.Materials and methods. The research was based on the relevant data obtained by several researchers in 2000–2018 on rock paleomagnetism. Results. The paleolatitudinal positions of the Eastern Ural microcontinent were determined, comprising 5.3 ± 7.4°) in the Middle Ordovician and 8.2 ± 7.2° in the Early–Middle Silurian. The respective paleolatitudinal positions for the Early–Middle Devonian comprised: the Ural margin of the Baltic paleocontinent (7.7 ± 3.7°), the Magnitogorsk island arc (3.2 ± 3.1°) and the Ural margin of the Kazakhstan paleocontinent (20.6 ± 3.8°).Conclusion. According to the analysed paleomagnetic data, in the Early–Middle Devonian, the distance between the latitudes of the margins of the Baltic and Kazakhstan continents was not less than 600 km provided they were in the same hemisphere, and more than 2,300 km provided they were in different hemispheres. The convergence of the terrains was associated with the subduction of the Ural Ocean crust before its closure, which occurred in the Tournaisian century.

scholarly journals Geological features and the first isotopic data of volcanic rocks in the Iset river basin, East-Urals megazone

2021 ◽  
Vol 1 ◽  
pp. 55-64
Author(s):  
Vasiliy Stanislavovich CHERVYAKOVSKIY
Keyword(s):  
River Basin ◽  
Large Scale ◽  
Volcanic Rocks ◽  
Early Carboniferous ◽  
Geological Structure ◽  
Geological Mapping ◽  
Isotopic Age ◽  
Isotopic Dating ◽  
Sedimentary Deposits ◽  
Tectonic Contact

Relevance of the work. The Iset river basin contains the most extensive outcrops of volcanogenic formations of the Beklenishchevsky complex of the East Ural megazone, the age of which is determined as Early Carboniferous by the ratio of volcanic rocks with faunistically characterized sedimentary deposits. Volcanics here compose flows of andesite-basaltic and andesitic lavas and lava breccias. There are no geochronological dates specifying the age of the rocks, which makes it difficult to assess their role in the formation of the megazone. Therefore, isotopic dating of these formations is very important. Methods. The U – Pb age and data on the geochemistry of zircons were obtained by laser ablation (LA – ICP – MS). Purpose of the research is to study the features of the geological structure, the material composition of volcanic rocks in the Iset river basin, the geochemistry of zircons from andesites and the determination of their isotopic age. Results of the work and the scope of their application. Lava flows of andesites and basaltic andesites with minor amounts of basalts and dacites have tectonic contact with sedimentary rocks of the Early Carboniferous age. The distribution of rare elements in volcanics is typical of supra-subduction formations. Zircons in andesites are represented by prismatic and isometric crystals. Prismatic differences in the nature of the distribution of REE and the content of Li, Ti, Sr, Th, U refer to zircons of magmatic genesis, isometric – to “hydrothermal”. According to the U / Yb – Y ratios, the former correspond to the zircons of the ocean floor, while the latter are related to the continental ones. Isotopic dating of zircons from andesites was carried out for the first time. Their age was 311 million years. The data can be used in geological mapping, as well as in the compilation of large-scale geodynamic maps and diagrams. Conclusions. Volcanic rocks in the Iset river basin were formed in supra-subduction continental-marginal geodynamic conditions that took place in the Urals in the Carboniferous. The obtained value of the age of zircons from andesites, possibly, fixes the stage of their transformation. Keywords: East-Ural megazone, volcanic rocks, zircon, isotopic age.

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