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.

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.

Russian Devonian brachiopod genera Cyrtinoides and Komiella in North America

1993 ◽  
Vol 67 (6) ◽  
pp. 952-958 ◽  
Author(s):  
J. G. Johnson ◽  
R. B. Blodgett
Keyword(s):  
New Species ◽  
North America ◽  
Carbonate Platform ◽  
Southern Urals ◽  
Late Devonian ◽  
Western North America ◽  
The Southern Urals ◽  
New Family ◽  
Marine Migration ◽  
Subjective Synonym

The Middle Devonian brachiopod genus Cyrtinoides, described from the southern Urals, is a senior subjective synonym of Mucroclipeus, previously known only from eastern and western North America. The Middle and Late Devonian cyrtinid brachiopod genus Komiella, previously known only from the Timan Range of eastern Europe, is identified from west-central Alaska and Nevada. A new family Komiellidae is proposed. New species are Komiella gilberti, K. magnasulca, and K. stenoparva. Known species of both genera occupy carbonate platform foreslope facies or shelf basins, allowing open marine migration via peripheral biofacies.

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.

scholarly journals Subduction, collision and plumes in the epoch of the Late Paleozoic magmatism of the Magnitogorsk zone (the Southern Urals)

LITOSFERA ◽  
2019 ◽  
pp. 191-208
Author(s):  
D. N. Salikhov ◽  
V. V. Kholodnov ◽  
V. N. Puchkov ◽  
I. R. Rakhimov
Keyword(s):  
Late Phase ◽  
Active Continental Margin ◽  
Southern Urals ◽  
Island Arc ◽  
Late Paleozoic ◽  
Time Interval ◽  
Geochemical Type ◽  
The Southern Urals ◽  
European Continent ◽  
East European

Subject. A systematization of Late-Paleozoic magmatic formations of the Magnitogorsk zone of the Southern Urals in the process of an accretion of the Magnitogorsk paleoarc to the margin of the East European continent (EEC) with formation in Famenian and Carboniferous active continent margin of South-Uralian accretionary-collisional belt was given in the work. Materials and methods. A generalization of published and manuscript materials characterizing magmatism and ore-mineralization of Magnitogorsk zone for the Devonian-Carboniferous-Permian time carried out, additional investigations of chemical composition of rocks (XRF, ISP-MS) characterizing process of accretion, subduction and plume activity, microelement distribution in them was made, the composition of rock-forming and accessory minerals (EPMA) was studied. Results. It is found that the South-Uralian accretionary-collisional belt was beginning to form in the late phase of the development of the Magnitogorsk island arc in the process its collision with EEC margin with formation in the Frasnian and Carboniferous of active continental margin. The products of Late-island-arc volcanism are represented by the porphyrite formation and in the eastern frame of the arc - by subalkaline monzonite-shoshonite-latite volcanic-intrusive association with intermediate characteristics between the subductional and interplate formations. Synchronously with them, in the backarc setting, picrite and meymechite volcanics − derivatives of a mantle plume are formed. In process of substitution of tectonic-magmatic regime from island-arc to margin-continental intraplate-type mantle series were forming. During this period, hot asthenospheric diapirs (plumes) were rising to the bottom of new-formed (accreted) margin-continental lithosphere. Along with the magmatic associations of intraplate type and rock series of intermediate geochemical type, this geodynamic situation in the Southern Urals is characterized by a presence of great volumes of mantle-crust granitoids of gabbro-tonalite-granodiorite-granite type, that were formed with a manifold manifestation of anatexis in a time interval of 365-290 Ma. Conclusion. On the whole the originality of Magnitogorsk zone geological history in the Devonian and Carboniferous, peculiarities of magmatic complexes formed here due to various geodynamic settings, are making this zone an extraordinary interesting and important object to study of processes of plume-lithosheric and mantle-crust interaction.

Biostratigraphy and taxonomy of fusulinid foraminifera across the Upper Mississippian (upper Serpukhovian)–Lower Pennsylvanian (Bashkirian) successions from the Hadim Nappe, Central Taurides, southern Turkey

2021 ◽  
pp. 1-21
Author(s):  
Melikan Akbaş ◽  
Cengiz Okuyucu
Keyword(s):  
New Species ◽  
Shallow Water ◽  
Late Cretaceous ◽  
Depositional Environment ◽  
Southern Urals ◽  
Russian Platform ◽  
Late Devonian ◽  
The Southern Urals ◽  
Southern Turkey ◽  
Stratigraphic Succession

Abstract The Hadim Nappe, which is one of the allochthonous tectonic units in the Tauride Belt, in southern Turkey, includes a continuous stratigraphic succession from the Middle(?)–Late Devonian to Late Cretaceous. A relatively complete succession of the upper Serpukhovian to Bashkirian is exposed in the Central Taurides, where two sections (Yassıpınar and Gölbelen) have been selected for detailed biostratigraphic investigations. The Mississippian-Pennsylvanian boundary in these sections was determined by the first appearance datum of the Plectostaffella jakhensis and located in the oolitic limestone facies indicating a shallow-water depositional environment. The uppermost Serpukhovian and regional Bashkirian substages (Syuranian, Akavasian, Askynbashian, and Arkhangelskian) were determined by index taxa, namely Plectostaffella jakhensis, P. bogdanovkensis, P. varvariensis, Pseudostaffella antiqua, Staffellaeformes staffellaeformis, Tikhonovichiella tikhonovichi, and Verella spicata. Fifty fusulinid species belonging to fourteen genera were determined in two sections, in which two species are new: Depratina turani Akbaş new species and Tikhonovichiella praetikhonovichi Akbaş new species. The taxonomic positions of two fusulinid species (Depratina convoluta n. comb. and Staffellaeformes parva robusta n. comb.) are revised. The studied fusulinid assemblages correlate with fusulinid assemblages from the southern Urals, Russian Platform, Donetz Basin, Darvaz, Spain, central Iran, and some other regions of the Tethyan Realm. UUID: http://zoobank.org/bcbb6c72-f6f9-4e77-9cf9-3572bd731ff3

scholarly journals Carboniferous continental margin mafic-ultramafic sheeted dyke complex in the West Magnitogorsk zone (Southern Urals)

2019 ◽  
pp. 42-50
Author(s):  
A. V. Ryazantsev ◽  
L. A. Novikov ◽  
A. A. Razumovskij
Keyword(s):  
Continental Margin ◽  
Active Continental Margin ◽  
Early Carboniferous ◽  
Southern Urals ◽  
Island Arc ◽  
Ultramafic Rocks ◽  
The West ◽  
Dyke Swarms

In the West of the aHochthon of Magnitogorsk zone thrusted onto the Precambrian complexes of the Uraltau zone, the Devonian island-arc complexes overlap stratigraphicalry the Ordovician and Silurian chert-basalt sequences and serpentine melange. Melange and Ordovician strata are intruded by dyke swarms and sheeted dykes («dyke in dyke») which are composed of mafic and ultramafic rocks. The dykes, composed by gabbro-dolerite, amphibole K-feldspar gabbro, hornblendite, picrite and lamprophyre, predominate. The composition of the ultramafic rocks corresponds to the composition of picrite and komatiite. The 40Ar/39Ar age of the magmatic amphibole from gabbro is 357 ± 8 m.y. The formation of dykes is related to the Early Carboniferous rift-related magmatism on an active continental margin.

scholarly journals Volcanism and intrusive magmatism of the Magnitogorsk paleoarc in the epoch of its “soft” collision with a margin of the East European continent

LITOSFERA ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 630-651
Author(s):  
D. N. Salikhov ◽  
V. V. Kholodnov ◽  
V. N. Puchkov ◽  
I. R. Rakhimov
Keyword(s):  
Chemical Elements ◽  
Early Carboniferous ◽  
Island Arc ◽  
Late Devonian ◽  
European Continent ◽  
East European ◽  
Icp Ms ◽  
Mantle Sources ◽  
Spatial Isolation ◽  
Academy Of Sciences

Research subject. The article sets out to investigate the change of the geodynamic regime from the island-arc type to the accretionary-collisional type in the Late Devonian–Early Carboniferous, which occurred as a result of 1) a collision between the Western part of the Magnitogorsk island arc and the Eastern margin of the East European continent and 2) its later coupling with the heterogeneous composite East Uralian terrain.Materials and methods. The content of petrogenic elements and microelements in the rocks of the Late Paleozoic island-arc complexes of the Magnitogorsk island arc were determined using XRF and ICP MS methods at the Laboratory of Physicochemical Research Methods of the Institute of Geology and Geochemistry, Ural Branch of the Russian Academy of Sciences. In addition, available publications on the composition and formation conditions of these complexes were reviewed.Results. It was found that, in the Late Devonian–Early Carboniferous period, the process of island-arc magmatism of the Magnitogorsk paleoarc was substituted with the formation of intraplate volcano-intrusive complexes. The island-arc magmageneration and its manifestations were controlled by a latitudinal linear zoning and different depths of formation of magmatic cameras, reflecting the self-consistency and spatial isolation of these events.Conclusion. Due to the intensifying collision, melts from different mantle sources were mixing, thus contaminating the island-arc rocks by intraplate (plume-dependent) magmas. According to the composition and concentrations of high-field strength and fluid-mobile chemical elements, suprasubductional fluids played an important role in the evolution of late-island arc magmatic series.

Sign in / Sign up

Export Citation Format

Share Document