Zirconology of izrandites (Southern Urals)     

Krasnobaev  A. A.  Puchkov  V. N.  Busharina  S. V.  Kozlov  V. I.  Presnyakov  S. L. 《Doklady Earth Sciences》2011,439(1):1021-1025

Doklady Earth Sciences -  相似文献   

The metamorphic complex of Beloretzk, SW Urals, Russia — a terrane with a polyphase Meso- to Neoproterozoic thermo-dynamic evolution     

U. A. Glasmacher  W. Bauer  U. Giese  P. Reynolds  B. Kober  V. Puchkov  L. Stroink  A. Alekseyev  A. P. Willner 《Precambrian Research》2001,110(1-4)

An integrated geological study of the tectono-metamorphic evolution of the metamorphic complex of Beloretzk (MCB) which is part of the eastern Bashkirian mega-anticlinorium (BMA), SW Urals, Russia shows that the main lithological units are Neoproterozoic (Riphean and Vendian age) siliciclastic to carbonate successions. Granitic, syenitic and mafic intrusions together with subaerial equivalents comprise the Neo- and Mesoproterozoic magmatic rocks. The metamorphic grade ranges from diagenetic and very low grade in the western BMA to high-grade in the MCB. The N–S trending Zuratkul fault marks the change in metamorphic grade and structural evolution between the central and eastern BMA. Structural data, Pb/Pb-single zircon ages, ⁴⁰Ar/³⁹Ar cooling ages and the provenance signature of Riphean and Vendian siliciclastic rocks in the western BMA give evidence of Mesoproterozoic (Grenvillian) rifting, deformation and eclogite-facies metamorphism in the MCB and a Neoproterozoic (Cadomian) orogenic event in the SW Urals. Three pre-Ordovician deformation phases can be identified in the MCB. The first SSE-vergent, isoclinal folding phase (D₁) is younger than the intrusion of mafic dykes (Pb/Pb-single zircon: 1350 Ma) and older than the eclogite-facies metamorphism. High P/low T eclogite-facies metamorphism is bracketed by D₁ and the intrusion of the Achmerovo granite (Pb/Pb-single zircon: ≤970 Ma). An extensional, sinistral, top-down-to-NW directed shearing (D₂) is correlated with the first exhumation of the MCB. E-vergent folding and thrusting (D₃) occurred at retrograde greenschist-facies metamorphic conditions. The tremolite ⁴⁰Ar/³⁹Ar cooling age (718±5 Ma) of amphibolitic eclogite and muscovite ⁴⁰Ar/³⁹Ar cooling ages (about 550 Ma) of mica schists indicate that a maximum temperature of 500±50 °C was not reached during the Neoproterozoic orogeny. The style and timing of the Neoproterozoic orogeny show similarities to the Cadomian-aged Timan Range NW of the Polar Urals. Geochronological and thermochronological data together with the abrupt change in structural style and metamorphism east of the Zuratkul fault, suggest that the MCB is exotic with respect to the SE-margin of the East European Platform. Thus, the MCB is named the ‘Beloretzk Terrane’. Recognition of the ‘Beloretzk Terrane’ and the Neoproterozoic orogeny at the eastern margin of Baltica has important implications for Neoproterozoic plate reconstruction and suggests that the eastern margin of Baltica might have lain close to the Avalonian–Cadomian belt.  相似文献   

Structural stages and evolution of the Urals     

V. N. Puchkov 《Mineralogy and Petrology》2013,107(1):3-37

Five main structural and historical stages are established in the territory of the Urals: 1) Archean-Paleoproterozoic, a time of formation of the Volgo-Uralia subcontinent and its amalgamation with the other blocks of the craton of Baltica; 2) Riphean-Vendian (Meso- and Neoproterozoic), а stage that was finished with formation of Timanides; 3) Paleozoic-Early Mesozoic stage, corresponding to the development of the Uralides; 4) Mid-Jurassic-to Miocene platform stage; 5) Pliocene-Quaternary neo-orogenic stage. In this paper stratigraphic data are discussed, schemes of the structural zonation are presented, and the problems of the structural geology and geodynamics of sedimentary and magmatic complexes are discussed in a chronological order. Ideologically, the paper is based on plate and plume tectonics, in their modern versions.  相似文献   

The structural peculiarities of the Dzhetygara-Troitsk Zone, Southern Urals (Based on the URSEIS-95 profile)     

S. E. Znamenskii  A. N. Svetlakova  V. N. Puchkov 《Doklady Earth Sciences》2013,448(1):31-34

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Geochemical peculiarities and the origin of deep gaseous-liquid inclusions of the Urals     

R. F. Abdrakhmanov  V. G. Popov  V. N. Puchkov 《Doklady Earth Sciences》2013,452(1):907-910

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First U–Pb isotopic data on zircon from andesite of the Saf’yanovka Cu-bearing massive sulfide deposit (Middle Urals)     

Yu. L. Ronkin  M. E. Pritchin  E. I. Soroka  A. Gerdes  V. N. Puchkov  S. V. Busharina 《Doklady Earth Sciences》2016,469(1):665-669

New results of U–Pb LA ICP–MS dating of zircon from andesite samples cropping out on the western wall of the Saf’yanovka quarry (57°22′58.88″ N, 61°31′50.85″ E) in the synonymous Cu–Zn-bearing massive sulfide deposit of the Urals type are considered. The position of data points of the U–Pb systematics in the ²⁰⁷Pb/²³⁵U–²⁰⁶Pb/²³⁸U plot determines a cluster practically corresponding to the concordant U–Pb age: 422.8 ± 2.0 Ma. This date indicates for the first time the presence of Pridolian volcanogenic rocks in the East Urals megazone of the Middle Urals.  相似文献   

New iron resources of the South Urals     

S. Sh. Yusupov  D. N. Salikhov  A. M. Kosarev  V. N. Puchkov 《Doklady Earth Sciences》2011,436(1):22-24

An area with brick-red loose and viscous sandy-clayey rocks and brown ores with an average Fe content of 19.84% and possible resources of 1 billion tons of metal was determined. Mn and Ti are the main alloying components; Ni, Co, Cr, V, and Zr are additional; and goethite (FeOOH) is an ore mineral.  相似文献   

Erratum to: Deformation-Induced Decomposition of Enstatite in Mantle Peridotite and Its Role in Partial Melting and Chromite Ore Formation     

Saveliev  D. E.  Puchkov  V. N.  Sergeev  S. N.  Musabirov  I. I. 《Doklady Earth Sciences》2019,484(1):114-114

Doklady Earth Sciences - The surname of the last co-author should read Musabirov  相似文献   

The timing and extent of the eruption of the Siberian Traps large igneous province: Implications for the end-Permian environmental crisis     

Marc K. Reichow  M.S. Pringle  A.I. Al'Mukhamedov  M.B. Allen  V.L. Andreichev  M.M. Buslov  C.E. Davies  G.S. Fedoseev  J.G. Fitton  S. Inger  A.Ya. Medvedev  C. Mitchell  V.N. Puchkov  I.Yu. Safonova  R.A. Scott  A.D. Saunders 《Earth and Planetary Science Letters》2009,277(1-2):9-20

We present new high-precision ⁴⁰Ar/³⁹Ar ages on feldspar and biotite separates to establish the age, duration and extent of the larger Siberian Traps volcanic province. Samples include basalts and gabbros from Noril'sk, the Lower Tunguska area on the Siberian craton, the Taimyr Peninsula, the Kuznetsk Basin, Vorkuta in the Polar Urals, and from Chelyabinsk in the southern Urals. Most of the ages, except for those from Chelyabinsk, are indistinguishable from those found at Noril'sk. Cessation of activity at Noril'sk is constrained by a ⁴⁰Ar/³⁹Ar age of 250.3 ± 1.1 Ma for the uppermost Kumginsky Suite.The new ⁴⁰Ar/³⁹Ar data confirm that the bulk of Siberian volcanism occurred at 250 Ma during a period of less than 2 Ma, extending over an area of up to 5 million km². The resolution of the data allows us to confidently conclude that the main stage of volcanism either immediately predates, or is synchronous with, the end-Permian mass extinction, further strengthening an association between volcanism and the end-Permian crisis. A sanidine age of 249.25 ± 0.14 Ma from Bed 28 tuff at the global section and stratotype at Meishan, China, allows us to bracket the P–Tr boundary to 0.58 ± 0.21 myr, and enables a direct comparison between the ⁴⁰Ar/³⁹Ar age of the Traps and the Permo–Triassic boundary section.Younger ages (243 Ma) obtained for basalts from Chelyabinsk indicate that volcanism in at least the southern part of the province continued into the Triassic.  相似文献   

Polychronous zirconology of syenites from the Avashla intrusion in the Kurgass anticline (Southern Urals)     

A. A. Krasnobaev  V. N. Puchkov  N. D. Sergeeva  S. P. Shokalski  S. V. Busharina 《Doklady Earth Sciences》2017,473(1):323-328

Zircons were separated from syenites of the Avashla intrusion in the Kurgass anticline of the Bashkir megaanticlinorium in the Southern Urals. The obtained samples were dated using the U–Pb procedure by means of a SHRIMP II ion microprobe. The integrated mineralogical, geochemical, and isotope studies of zircons resulted in primary data on the origin and current conditions of zircons in syenites of the Avashla intrusion. The relics of early zircon generations (1320–1340 Ma) allowed us to specify the geological position of syenites along with the stratigraphic location of the enclosing sedimentary rocks. The time of the transformation (metamorphism) of the zircons at the Middle–Upper Riphean boundary is represented by a dating of 1097±20 Ma, which is of importance for specifying the boundary age and for revealing a geological event that started a new development stage of the stratoregion in the Upper Riphean.  相似文献