Nature and Age of Detrital Zircons from Rocks of the Shear Zone: The Problem of Occurrence of the Archean Basement in the Transangarian Yenisei Ridge     

I. I. Likhanov  P. S. Kozlov  V. V. Reverdatto  N. V. Popov 《Doklady Earth Sciences》2018,480(1):568-572

Petrogeochemical and geochronological study of boudined quartzite sandstones and tonalites, as well as host amphibolites, in the shear zone showed that potential sources of detrital zircons were Neoarchean–Paleoproterozoic rocks of the Angara–Kan block and products of their metamorphism. Interpretation of the available data does not confirm the inferred presence of the Early Precambrian basement of the Siberian Craton in the Transangara region.  相似文献   

New Data on the Age of the Tonalite–Trondhjemite Orthogneisses of the Olekma Complex of the Central Part of the Chara–Olekma Geoblock,Aldan Shield     

S. D. Velikoslavinskii  A. B. Kotov  E. B. Sal’nikova  A. B. Kuznetsov  V. P. Kovach  N. V. Popov  E. V. Tolmacheva  I. V. Anisimova  Yu. V. Plotkina 《Doklady Earth Sciences》2018,482(2):1265-1269

New U–Pb zircon (TIMS) results allow dating of protoliths of tonalite–trondhjemite orthogneisses of the Olekma Complex in the central part of the Chara–Olekma Geoblock (Aldan Shield) to 2825 ± 3 Ma and 2994 ± 3 Ma. Together with the results of previous geochronological studies, this proves that the Olekma Complex comprises heterochronous igneous rocks intensively reworked under amphibolite facies conditions and formed during different stages of geological evolution of the Aldan Shield.  相似文献   

The possibility of emersion of the outer layers in a massive star simultaneously with iron-core collapse: A hydrodynamic model     

V. S. Imshennik  K. V. Manukovskii  D. K. Nadyozhin  M. S. Popov 《Astronomy Letters》2002,28(12):821-834

We analyze the behavior of the outer envelope in a massive star during and after the collapse of its iron core into a protoneutron star (PNS) in terms of the equations of one-dimensional spherically symmetric ideal hydrodynamics. The profiles obtained in the studies of the evolution of massive stars up to the final stages of their existence, immediately before a supernova explosion (Boyes et al. 1999), are used as the initial data for the distribution of thermodynamic quantities in the envelope. We use a complex equation of state for matter with allowances made for arbitrary electron degeneracy and relativity, the appearance of electron-positron pairs, the presence of radiation, and the possibility of iron nuclei dissociating into free nucleons and helium nuclei. We performed calculations with the help of a numerical scheme based on Godunov's method. These calculations allowed us to ascertain whether the emersion of the outer envelope in a massive star is possible through the following two mechanisms: first, the decrease in the gravitational mass of the central PNS through neutrino-signal emission and, second, the effect of hot nucleon bubbles, which are most likely formed in the PNS corona, on the envelope emersion. We show that the second mechanism is highly efficient in the range of acceptable masses of the nucleon bubbles (≤0.01M _⊙) simulated in our hydrodynamic calculations in a rough, spherically symmetric approximation.  相似文献   

Observations of neutral hydrogen in the corona     

I. S. Kim  V. V. Popov  D. V. Lisin  A. P. Osokin 《Geomagnetism and Aeronomy》2013,53(7):901-903

Measurements of the linear polarization degree (p) of the emission in the inner corona (<1.5 R _⊙) in the green and red continuum ranges are discussed. “Excess p” (Δp = pgreen — pred), which reaches its maximum at 1.2–1.3 R _⊙ (<5%) in the polar regions and 20% within large-scale streamers, is present everywhere in the corona. It has been mentioned that excess p can be explained by the presence of neutral hydrogen in the corona.  相似文献   

Kuranakh complex diabases in the western part of the Aldan-Stanovoi Shield: Age and tectonic setting     

N. V. Popov  A. B. Kotov  E. B. Salnikova  A. A. Postnikov  V. F. Timofeev  V. I. Berezkin  A. M. Larin  A. M. Fedoseenko  S. Z. Yakovleva 《Doklady Earth Sciences》2012,442(1):45-48

The age of Kuranakh Complex diabases in the western part of the Aldan-Stanovoi Shield determined by the zircon U-Pb method is virtually identical to that of basic rocks in the Chinei stratified pluton and granites in the Kodar Complex. Thus, it is possible to suggest that they form a unified bimodal magmatic association and belong to the South Siberian postcollision magmatic belt, which extends along the southwestern framing of the Siberian Craton for more than 2500 km from the Yenisei mountain range to the Aldan-Stanovoi Shield. The occurrence of the diabase dike swarms in magmatic associations of this belt testifies to formation under lithospheric extension conditions.  相似文献   

Middle-Upper Miocene stratigraphy of the Taman Peninsula, Eastern Paratethys     

Eleonora P. Radionova  Larisa A. Golovina  Natalia Yu. Filippova  Valery M. Trubikhin  Sergey V. Popov  Irina A. Goncharova  Yulia V. Vernigorova  Tatiana N. Pinchuk 《Central European Journal of Geosciences》2012,4(1):188-204

The stratigraphy of the Taman Peninsula is defined using the sections at Zelensky Hill ?? Panagia, Popov Kamen, Taman and Zheleznyi Rog. The stratigraphy is constructed from distribution of mollusks, foraminifers, nannofossils, diatoms, and organic-walled phytoplankton, as well as incorporating paleomagnetic data. The occurrence of oceanic diatom species in the Middle-Upper Sarmatian, Maeotian and Lower Pontian makes a direct correlation possible between the sections studied, the Mediterranean basin and oceanic zonation. The new data on planktonic and benthic biotic groups suggests a pulsating connection of the Eastern Paratethys with the open marine basins, especially during transitional intervals within constant environments. Comprehensive studies of the Chokrakian-Kimmerian microbiota provide evidence for several levels of marine microbiotic associations that are related to short-term marine invasions. The biotic and paleomagnetic data of the Taman Peninsula sections give a more comprehensive, but sometimes a controversial picture on the Eastern Paratethys history and the nature of its relationship with the adjacent marine basins.  相似文献   

Differentiated gabbroids of the South Yenisei Ridge: Evidence for early proterozoic subduction events     

N. V. Popov  A. E. Izokh 《Doklady Earth Sciences》2013,450(1):539-543

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The MASTER-II network of robotic optical telescopes. First results     

E. S. Gorbovskoy  V. M. Lipunov  V. G. Kornilov  A. A. Belinski  D. A. Kuvshinov  N. V. Tyurina  A. V. Sankovich  A. V. Krylov  N. I. Shatskiy  P. V. Balanutsa  V. V. Chazov  A. S. Kuznetsov  A. S. Zimnukhov  V. P. Shumkov  S. E. Shurpakov  V. A. Senik  D. V. Gareeva  M. V. Pruzhinskaya  A. G. Tlatov  A. V. Parkhomenko  D. V. Dormidontov  V. V. Krushinsky  A. F. Punanova  I. S. Zalozhnyh  A. A. Popov  A. Yu. Burdanov  S. A. Yazev  N. M. Budnev  K. I. Ivanov  E. N. Konstantinov  O. A. Gress  O. V. Chuvalaev  V. V. Yurkov  Yu. P. Sergienko  I. V. Kudelina  E. V. Sinyakov  I. D. Karachentsev  A. V. Moiseev  T. A. Fatkhullin 《Astronomy Reports》2013,57(4):233-286

The main stages in the creation of the Russian segment of the MASTER network of robotic telescopes is described. This network is designed for studies of the prompt optical emission of gammaray bursts (GRBs; optical emission synchronous with the gamma-ray radiation) and surveys of the sky aimed at discovering uncataloged objects and photometric studies for various programs. The first results obtained by the network, during its construction and immediately after its completion in December 2010, are presented. Eighty-nine alert pointings at GRBs (in most cases, being the first ground telescopes to point at the GRBs) were made from September 2006 through July 2011. The MASTER network holds first place in the world in terms of the total number of first pointings, and currently more than half of first pointings at GRBs by ground telescopes are made by the MASTER network. Photometric light curves of GRB 091020, GRB 091127, GRB 100901A, GRB 100906A, GRB 10925A, GRB 110106A, GRB 110422A, and GRB 110530A are presented. It is especially important that prompt emission was observed for GRB 100901A and GRB 100906A, and thar GRB 091127, GRB 110422A, and GRB 110106A were observed from the first seconds in two polarizations. Very-wide-field cameras carried out synchronous observations of the prompt emission of GRB 081102, GRB 081130B, GRB 090305B, GRB 090320B, GRB 090328, and GRB 090424. Discoveries of Type Ia supernovae are ongoing (among them the brightest supernova in 2009): 2008gy, 2009nr, 2010V, and others. In all, photometry of 387 supernovae has been carried out, 43 of which were either discovered or first observed with MASTER telescopes; more than half of these are Type Ia supernovae. Photometric studies of the open clusters NGC 7129 and NGC 7142 have been conducted, leading to the discovery of 38 variable stars. Sixty-nine optical transients have been discovered.  相似文献   

Mariinskite, BeCr2O4, a new mineral, chromium analog of chrysoberyl     

L. A. Pautov  M. P. Popov  Yu. V. Erokhin  V. V. Khiller  V. Yu. Karpenko 《Geology of Ore Deposits》2013,55(8):648-662

A new mineral, mariinskite, BeCr₂O₄, the chromium analog of chrysoberyl, has been found at the Mariinsky (Malyshevo) deposit, the Ural Emerald Mines, the Central Urals, Russia. The mineral is named after its type locality. It was discovered in chromitite in association with fluorphlogopite, Cr-bearing muscovite, eskolaite, and tourmaline. Mariinskite occurs as anhedral grains ranging from 0.01 to 0.3 mm in size; in some cases it forms pseudohexagonal chrysoberyl-type twins. The mineral is dark-green, with a pale green streak; the Mohs’ hardness is 8.5, microhardness VHN = 1725 kg/mm². D _meas = 4.25(2) g/cm³, D _calc = 4.25 g/cm³. Microscopically, it is emerald-green, pleochroic from emerald-green (γ) to yellow-green (β) and greenish yellow (α). The new mineral is biaxial (+), γ = 2.15(1), β = 2.09(3), and α = 2.05(1), 2V _meas = 80 ± (10)°, 2V _calc = 80.5°. In reflected light, it is gray with green reflections; R _max (589) = 12.9%; R _min (589) = 12.3%, and there are strong, internal green reflections. The strongest absorption bands in the IR spectrum are as follows (cm^?1): 935, 700, 614, 534. Space group Pnma, a = 9.727(3), b = 5.619(1), c = 4.499(1) Å, V = 245.9(3) ų, Z = 4. The strongest reflections in the X-ray powder diffraction pattern are as follows (d Å, I, hkl): 4.08(40)(101), 3.31(90)(111), 2.629(50)(301), 2.434(50)(220), 2.381(40)(311), 2.139(60)(221), 1.651(100)(222). The average chemical composition of mariinskite (electron microprobe, wt %) is as follows: BeO 16.3, Al₂O₃ 23.89, Cr₂O₃ 58.67, Fe₂O₃ 0.26, V₂O₃ 0.26, TiO₂ 0.61, total is 99.98. The empirical formula, calculated on the basis of four O atoms is Be_1.03(Cr_1.22Al_0.74Ti_0.01Fe_0.01V_0.01)_1.99O₄. The compatibility index 1 ? (K_p/K_c), 0.019, is excellent. The type specimens are deposited in the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow, and the Ural Geological Museum, Yekaterinburg, Russia.  相似文献   

Climatic Reasons for the Current Expansion of the Range of the Italian Locust in Russia and Neighboring Countries     

Popova  E. N.  Popov  I. O. 《Doklady Earth Sciences》2019,488(2):1256-1258

Doklady Earth Sciences - The species climatic range of a dangerous locust pest, called the Italian locust, was modelled for the territories of Russia and neighboring countries over two time periods...  相似文献