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

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.

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

LITOSFERA ◽

10.24930/1681-9004-2019-19-2-191-208 ◽

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.

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

Moscow University Geology Bulletin ◽

10.3103/s0145875208060021 ◽

2008 ◽

Vol 63 (6) ◽

pp. 359-367 ◽

Cited By ~ 1

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

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DEVONIAN-CARBONIFEROUS MAGMATISM AND METALLOGENY IN THE SOUTH URAL ACCRETIONARY-COLLISIONAL SYSTEM

Geodynamics & Tectonophysics ◽

10.5800/gt-2021-12-2-0529 ◽

2021 ◽

Vol 12 (2) ◽

pp. 365-391 ◽

Cited By ~ 1

Author(s):

A. M. Kosarev ◽

A. G. Vladimirov ◽

A. I. Khanchuk ◽

D. N. Salikhov ◽

V. B. Kholodnov ◽

...

Keyword(s):

Subduction Zone ◽

Large Scale ◽

Volcanic Eruptions ◽

Early Carboniferous ◽

Massive Sulfide ◽

Island Arc ◽

South Urals ◽

Late Devonian ◽

The South ◽

Volcanic Cycles

The oceanic stage in the history of the South Urals completed in the Ordovician – Early Silurian. The Ordovician through Devonian events in the region included the formation of an island arc in the East Ural zone from the Middle Ordovician to Silurian; westward motion of the subduction zone in the Late Silurian – Early Devonian and the origin of a trench along the Main Ural Fault and the Uraltau Uplift; volcanic eruptions and intrusions in the Magnitogorsk island arc system in the Devonian. The Middle-Late Paleozoic geodynamic evolution of uralides and altaides consisted in successive alternation of subduction and collisional settings at the continent-ocean transition. The greatest portion of volcanism in the major Magnitogorsk zone was associated with subduction and correlated in age and patterns of massive sulfide mineralization (VMS) with Early – Middle Devonian ore-forming events in Rudny Altai. Within-plate volcanism at the onset of volcanic cycles records the Early (D1e2) and Middle (D2ef2) Devonian slab break off. The volcanic cycles produced, respectively, the Buribay and Upper Tanalyk complexes with VMS mineralization in the Late Emsian; the Karamalytash complex and its age equivalents in the Late Eifelian – Early Givetian, as well as the lower Ulutau Formation in the Givetian. Slab break off in the Late Devonian – Early Carboniferous obstructed the Magnitogorsk island arc and supported asthenospheric diapirism. A new subduction zone dipping westward and the Aleksandrovka island arc formed in the Late Devonian – Early Carboniferous. The Early Carboniferous collision and another event of obstructed subduction led to a transform margin setting corresponding to postcollisional relative sliding of plates that produced another slab tear. Postcollisional magmatism appears as alkaline gabbro-granitic intrusives with related rich Ti-magnetite mineralization (C1). Transform faulting persisted in the Middle Carboniferous through Permian, when the continent of Eurasia completed its consolidation. The respective metallogenic events included formation of Cu-Ni picritic dolerites (C2–3), as well as large-scale gold and Mo-W deposits in granites (P1–2).

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The timing of Barleik Formation and its implication for the Devonian tectonic evolution of Western Junggar, NW China

Open Geosciences ◽

10.1515/geo-2020-0229 ◽

2021 ◽

Vol 13 (1) ◽

pp. 188-196

Author(s):

Yuanxiu Hui ◽

Ran Wang ◽

Lu Li ◽

Jingyu Lin ◽

Zhouxuan Xiao ◽

...

Keyword(s):

Tectonic Evolution ◽

Sedimentary Environment ◽

Weighted Average ◽

Island Arc ◽

Late Devonian ◽

Adjacent Area ◽

Nw China ◽

Icp Ms ◽

Invertebrate Fossils ◽

Tectonic Belt

Abstract The timing of Barleik Formation in Xinjiang, NW China, has not been constrained by accurate geochronology yet, while this work is of great significance to help reconstruct the geological tectonic evolution of Western Junggar. Based on the LA-ICP-MS U–Pb geochronology study, the weighted average age of magmatic zircons collected from the tuff in Barleik Formation, which reflects the formation age of the tuff, is 372 ± 2 Ma (N = 57, mean square of weighted deviates (MSWD) = 1.15). The first report in this study of the zircon U–Pb dating result indicates that Barleik Formation along the West Junggar tectonic belt occurred in the Late Devonian rather than in the middle Devonian period as previously claimed. Meanwhile, chronology data and the geochemical features comparing with the Island Arc-related rocks in the adjacent area, as well as stratigraphic structural relationship, suggest that volcanic activities may exist in the Late Devonian, and the relevant volcanic ash deposited in the Barleik forearc basin may be derived from the adjacent island arc (current geographic coordinate). In addition, the fossil assemblage dominated by bathyal-abyssal invertebrate fossils and bathyal-abyssal facies indicates that the Barleik Formation is a bathyal-abyssal sedimentary environment.

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EARLY REPRESENTATIVES OF BRYOZOANS FROM GENUS NIKIFOROVELLA NEKHOROSHEV, 1948 AND THEIR STRATIGRAPHICAL SIGNIFICANCE FOR LATE DEVONIAN-EARLY CARBONIFEROUS

10.24930/1681-9004-2017-17-5-053-066 ◽

2017 ◽

Vol 17 (5) ◽

pp. 53-66

Author(s):

Zoya A. Tolokonnikova ◽

◽

Keyword(s):

Early Carboniferous ◽

Late Devonian

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Late Devonian–early Carboniferous contraction-dominated deformation in Central Armorica (Monts d'Arrée, Brittany, France) and its relationship with the closure of the Rheic Ocean

Tectonophysics ◽

10.1016/j.tecto.2008.05.023 ◽

2008 ◽

Vol 461 (1-4) ◽

pp. 343-355 ◽

Cited By ~ 5

Author(s):

Manuel Sintubin ◽

Michiel van Noorden ◽

Isaac Berwouts

Keyword(s):

Early Carboniferous ◽

Late Devonian ◽

Rheic Ocean

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The origin and early radiation of terrestrial vertebrates

Journal of Paleontology ◽

10.1017/s0022336000017248 ◽

2001 ◽

Vol 75 (6) ◽

pp. 1202-1213 ◽

Cited By ~ 16

Author(s):

Robert L. Carroll

Keyword(s):

Fossil Record ◽

Early Carboniferous ◽

Late Devonian ◽

Lower Carboniferous ◽

Major Transitions ◽

Terrestrial Vertebrates ◽

History Of ◽

Paleozoic Tetrapods ◽

Early Radiation ◽

Ways Of Life

The origin of tetrapods from sarcopterygian fish in the Late Devonian is one of the best known major transitions in the history of vertebrates. Unfortunately, extensive gaps in the fossil record of the Lower Carboniferous and Triassic make it very difficult to establish the nature of relationships among Paleozoic tetrapods, or their specific affinities with modern amphibians. The major lineages of Paleozoic labyrinthodonts and lepospondyls are not adequately known until after a 20–30 m.y. gap in the Early Carboniferous fossil record, by which time they were highly divergent in anatomy, ways of life, and patterns of development. An even wider temporal and morphological gap separates modern amphibians from any plausible Permo-Carboniferous ancestors. The oldest known caecilian shows numerous synapomorphies with the lepospondyl microsaur Rhynchonkos. Adult anatomy and patterns of development in frogs and salamanders support their origin from different families of dissorophoid labyrinthodonts. The ancestry of amniotes apparently lies among very early anthracosaurs.

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