On the problem of the scale and composition of Paleozoic and Mesozoic granitoid magmatism in the Khilok–Vitim fold belt of Central Transbaikalia     

A. Yu. Antonov  A. V. Travin 《Russian Journal of Pacific Geology》2016,10(2):105-122

The paper presents a study of the gneissic granitoids of the Malkhan Complex and the intruisve granitoids of the Daur and Bichur complexes developed within the Khilok–Vitim fold belt of Central Transbaikalia. In the state geological map, these complexes have been attributed to the Early and Late Paleozoic. New ⁴⁰Ar/³⁹Ar geochronological data indicate that these rocks are Mesozoic rather than Paleozoic in age, which suggests the much broader manifestation of the Mesozoic granitoid complexes in this area. The studied Mesozoic granitoid massifs exhibit temporal and compositional zoning reflected in a westward decrease in age (from Early to Late Mesozoic) and increase in total alkalinity and potassium content at the appropriate trace-element characteristics. The obtained results of study of the Khilok–Vitim Belt are interpreted in the framework of the model of the formation of domal–cupola structures by the multiple activity of deep thermochemical plumes.  相似文献   

Sr and Nd isotopic compositions of kimberlites and associated rocks of the Siberian craton     

A. V. Lapin  A. V. Tolstov  A. V. Antonov 《Doklady Earth Sciences》2007,414(1):557-560

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Steady-state double layer structures in the interstellar medium     

V. A. Antonov  A. S. Baranov  V. V. Pashkevich 《Astrophysics》2009,52(4):571-583

A one-dimensional, self consistent theoretical model is constructed for double layers in a thermodynamically nonequilibrium astrophysical plasma. A steady state is maintained by an asymmetry in the fluxes from both sides. The range of possible values of the parameters is determined.  相似文献   

Evaluation of Cytotoxicity and Genotoxicity of Insecticide Carbaryl to Flounder Gill Cells and Its Teratogenicity to Zebrafish Embryos     

EY Manish Raj  GUO Huarong 《中国海洋大学学报(英文版)》2015,(2):362-374

In this study, we determined the cytotoxicity and genotoxicity of carbamate insecticide carbaryl to flounder gill(FG) cells and its teratogenicity to zebrafish embryos. The cytotoxicity of carbaryl to FG cells was determined with methods including MTT and neutral red uptaking(NRU), lactate dehydrogenase(LDH) releasing and Hoechst 33342 and propidium idodide(PI) double staining. Moderate cytotoxicity in a concentration-dependent manner was observed. The 24 h-IC50 value of 53.48 ± 1.21, 59.13 ± 1.19 and 46.21 ± 1.24 mg L-1 carbaryl was obtained through MTT, NRU and LDH assays, respectively. Double fluorescence staining demonstrated that carbaryl induced the death of FG cells mainly through necrosis. There was no significant genotoxicity found in the FG cells exposed to the highest testing concentration of carbaryl(20 mg L-1, P 0.05) as was demonstrated by Comet assay. Zebrafish embryos exposed to carbaryl at concentrations ≥10 mg L-1 displayed moderate toxic effects on the survival, spontaneous movement, hatching, heart rates of the embryos and their development, which were evidenced by yolk and pericardial sac edemas, body length reduction and tail flexure in time- and concentration-dependent manners at specific stages. The 24 h-, 48 h- and 96 h-LC50 values of carbaryl to zebrafish embryos were 41.80 ± 1.10, 17.80 ± 1.04 and 14.46 ± 1.05 mg L-1, respectively. These results suggested that carbaryl is moderately toxic to FG cells cultured in vitro and zebrafish embryos, and the FG cells were similar to zebrafish embryos in their sensitivity to carbaryl as 24 h-IC50 and LC50 indicated.  相似文献   

Supergiant Complexes of Solar Activity and Convection Zone     

O. V. Arkhypov  O. V. Antonov  M. L. Khodachenko 《Solar physics》2011,270(1):1-8

The global distribution of solar surface activity (active regions) is apparently connected with processes in the convection zone. The large-scale magnetic structures above the tachocline could in a pronounced way be observable in the surface magnetic field. To get the information regarding large-scale magnetic formations in the convection zone, a set of solar synoptic charts (Mount Wilson 1998 – 2004, Fe i, 525.02 nm) have been analyzed. It is shown that the longitudinal dimensions and dynamics of supergiant complexes of solar surface activity carry valuable information about the processes in the convection zone of the Sun. A clear effect of large-scale (global) turbulence is found. This is a ‘fingerprint’ of deep convection, because there are no such large-scale turbulent eddies in the solar photosphere. The preferred scales of longitudinal variations in surface solar activity are revealed. These are: ∼ 24° (gigantic convection cells), 90°, 180° and 360°.  相似文献   

Zircon trace element characteristics and ages in granulite xenoliths: a key to understanding the age and origin of the lower crust,Arkhangelsk kimberlite province,Russia     

M.?Yu.?KoreshkovaEmail author  H.?Downes  V.?A.?Glebovitsky  N.?V.?Rodionov  A.?V.?Antonov  S.?A.?Sergeev 《Contributions to Mineralogy and Petrology》2014,167(2):973

Garnet granulite and pyroxenite xenoliths from the Grib kimberlite pipe (Arkhangelsk, NW Russia) represent the lower crust beneath Russian platform in close vicinity to the cratonic region of the north-eastern Baltic (Fennoscandian) Shield. Many of the xenoliths have experienced strong interaction with the kimberlite host, but in others some primary granulite-facies minerals are preserved. Calculated bulk compositions for the granulites suggest that their protoliths were basic to intermediate igneous rocks; pyroxenites were ultrabasic to basic cumulates. A few samples are probably metasedimentary in origin. Zircons are abundant in the xenoliths; they exhibit complex zoning in cathodoluminescence with relic cores and various metamorphic rims. Cores include oscillatory zircon crystallized in magmatic protoliths, and metamorphic and magmatic sector-zoned zircons. Recrystallization of older zircons led to the formation of bright homogeneous rims. In some samples, homogeneous shells are surrounded by darker convoluted overgrowths that were formed by subsolidus growth when a change in mineral association occurred. The source of Zr was a phase consumed during a reaction, which produced garnet. Late-generation zircons in all xenoliths show concordant U–Pb ages of 1.81–1.84 Ga (1,826 ± 11 Ma), interpreted as the age of last granulite-facies metamorphism. This event completely resets most zircon cores. An earlier metamorphic event at 1.96–1.94 Ga is recorded by some rare cores, and a few magmatic oscillatory zircons have retained a Neoarchaean age of 2,719 ± 14 Ma. The assemblage of metaigneous and metasedimentary rocks was probably formed before the event at 1.96 Ga. Inherited magmatic zircons indicate the existence of continental crust by the time of intrusion of magmatic protoliths in the Late Archaean. The U–Pb zircon ages correspond to major events recorded in upper crustal rocks of the region: collisional metamorphism and magmatism 2.7 Ga ago and reworking of Archaean rocks at around 1.95–1.75 Ga. However, formation of the granulitic paragenesis in lower crustal rocks occurred significantly later than the last granulite-facies event seen in the upper crust and correlates instead with retrograde metamorphism and small-volume magmatism in the upper crust.  相似文献   

Stability of self-gravitating homogeneous spheroid with azimuthal magnetic field. I     

V. A. Antonov  O. A. Zheleznyak 《Astrophysics》1987,27(1):401-404

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The benchmark network for ecological monitoring of the Baikal natural territory     

A. S. Pleshanov  V. M. Plyusnin  S. I. Shamanova  A. A. Sorokovoi  S. G. Kazanovskii  A. V. Verkhozina  I. A. Antonov  I. N. Shekhovtsova  A. S. Kaverzina  O. A. Chernysheva 《Geography and Natural Resources》2012,33(1):33-36

Using an ingenious cartographic method, for the Baikal natural territory we have developed a benchmark network that includes 18 tracts (0.47% of the territory under consideration). Special-purpose ground-based surveys of the selected tracts showed that such a network fully reflects the landscape diversity on the level of geoms, the phytocenotic diversity, and the species diversity of the regional biota.  相似文献   

Evolution of extended clouds of particles near the sun and stars     

V. A. Antonov  A. S. Baranov 《Astrophysics》2009,52(3):395-411

The evolution of the trajectories of small objects not entirely ejected from the solar system and subject to significant perturbations owing to the regular galactic field is studied. These objects may be individual dust particles, comets, or, in the case of other stars, large dust clouds and stellar satellites. The possibility of averaging their motion over the period of the galactic rotation is examined. The averaged equations are solved in terms of elliptic functions. The eccentricity of the orbit also evolves, but returns periodically to its original value, ~1, corresponding to ejection if the interaction with individual stars is neglected. The slope of the line of apsides with respect to the galactic plane evolves in two ways: with time it either passes through 90° or through 0°.  相似文献   

Isotopic-Geochemical Features of Zircon and Its Significance for Reconstructing the Geological History of Paleoarchean Granulites in the Ukrainian Shield     

S. B. Lobach-Zhuchenko  T. V. Kaulina  K. I. Lokhov  Yu. S. Egorova  S. G. Skublov  O. L. Galankina  A. V. Antonov 《Geology of Ore Deposits》2017,59(8):663-676

This paper presents the results of a complex study (morphology of grains, internal texture in cathodoluminescence and backscattered electrons, microprobe analysis, Lu–Hf data) of five groups (generations) of zircon crystals differing in age and separated from the same granulite sample pertaining to the Bug River Complex of the Ukrainian Shield. The data show that the oldest zircon crystals of the first group (3.74 Ga in age) are xenogenic and initially crystallized from a granitic melt; zircon of the second group (3.66 Ga) formed from a mafic melt contaminated by felsic country rocks. The third group (3.59 Ga) is represented by zircons that formed about 100 Ma later than the second group under conditions of granulite-facies metamorphism and with the participation of fluid-saturated anatectic melt. Two Paleoproterozoic zircon groups (~2.5 and 2.1 Ga) also formed under granulite-facies conditions; to a certain extent, their structure and composition were controlled by fluid. The geochemistry of all zircon generations provides evidence for their crystallization in the continental crust, but from the sources differing in the contribution of mantle-derived material and in oxygen fugacity.  相似文献