Phase transformations of enstatite in spherical shock waves     

E. A. Kozlov  L. V. Sazonova 《Petrology》2012,20(4):336-346

The analysis of available theoretical evaluations and experimental data reveals discrepancies and makes it possible to formulate the goals for the comprehensive study of the behavior of enstatite MgSiO₃ in shock isentropic waves of various scale and intensity. The paper presents the layout and results of an explosion experiment on the compression of an enstatite sphere with spherical shock waves and the subsequent recovery of the experimental material and its examination in discrete zones (along the sphere radius) that were produced by shock waves in the material. The latter were examined with the application of scanning electron microscopy, Raman spectroscopy, and X-ray diffraction analysis. The comparison of the systematic variations in the texture, chemistry, and phase composition of enstatite along the sphere radius with calculated pressure P(R, t) and temperature T(R, t) values led us to the following conclusions: enstatite starts melting on an isentrope upon pressure relief after shock wave compression at ?? _xx ?? 80 GPa and melts on the front of the spherically converging shock wave at ?? _xx ?? 160 GPa and T ?? 6300 K. Our laboratory experiments with shock waves were the world??s first in which enstatite was loaded with spherical converging shock isentropic waves and which provided evidence that shock wave-loaded MgSiO₃ shows certain morphological and mineralogical features never before detected in this mineral loaded with plane shock wave of smaller amplitude and duration. Goals are formulated for the further studying of shock wave-loaded materials, and the necessity is discussed for conducting an explosion experiment with a five to seven times greater spherical system in order to increase the duration of the shock wave loading impulse.  相似文献   

The first find of rapakivi granite in the Yenisei ridge: Age, <Emphasis Type="Italic">PT</Emphasis> conditions,and tectonic settings     

I. I. Likhanov  V. V. Reverdatto  N. V. Popov  P. S. Kozlov 《Doklady Earth Sciences》2012,443(1):365-370

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The neoproterozoic Trans-Angara dike belt, Yenisei Range, as an indicator of extension and breakup of Rodinia     

I. I. Likhanov  V. V. Reverdatto  P. S. Kozlov  S. V. Zinov’ev 《Doklady Earth Sciences》2013,450(2):613-617

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Specific features of variations in the characteristics of VLF signals when the lunar shadow propagated along the path during the solar eclipse of March 29, 2006     

R. R. Karimov  V. I. Kozlov  V. A. Mullayarov 《Geomagnetism and Aeronomy》2008,48(2):240-244

The effects of the solar eclipse of March 29, 2006, in the signals of ULF radio stations, in the intensity of regular radio noise at frequencies of 0.3–10 kHz, and in the number of atmospherics received in Yakutsk mostly from the west have been considered. The observations were performed using a multichannel parallel analyzer-recorder (11 channels in the frequency band 0.47–8.7 kHz), one-point lightning direction and range finder (0.3–100 kHz), narrow-sector radio noise direction-finder (0.3–10 kHz), recorder of signals from VLF radio stations, and broadband radio noise recorder (0.3–100 kHz). A GPS clock was used to synchronize a recorder of signals from VLF radio stations. The effect was observed in radio signals, radio noise, and number of atmospherics from the direction 270° ± 20° counted off clockwise from the north during the last stage of the eclipse (～ 1100–1200 UT), when the lunar shadow approached the line of the nighttime terminator and obscured part of the signal propagation path. The effect was observed as an enhancement of the received signals by a factor of ～1.2, a factor of ～1.4 increase in the number of atmospherics, and a change in the radio station phase values.  相似文献   

Structural–formational interpretation tools for seismic stratigraphy     

I.A. Mushin  V.V. Makarov  E.A. Kozlov  A. Lowrie 《Geophysical Prospecting》2000,48(6):953-981

In the framework of a structural-and-formational interpretation (SFI) approach to seismic data processing and geological interpretation, specific software/technology tools were created to facilitate sequence stratigraphy analysis and reservoir characterization. The most important tools are two types of time–frequency representation of seismic data: the first is spectrum-time analysis (STAN), which presents a seismic trace as a series of very narrow frequency band traces, while the second tool converts an initial seismic section into a set of sections ranked with preselected frequency bands, narrower than those of the initial section, but wider than those related to STAN traces. Jointly, these two representations reflect both general trends and local temporal and spatial variations of seismic data frequency content. The use of these tools, developed in Russia in the 1980s, facilitates detection of sedimentation cycles and their depositional environments, identification of hierarchies within faulting patterns, and delineation of geological anomalies on seismic sections. This, in turn, provides reliable starting points for palaeotectonic restoration and basin modelling. In many regions, these tools have helped to clarify obscure formation structures under study and to estimate the hydrocarbon potential of these formations.  相似文献   

The Crust–Mantle Carbon Cycle and Origin of Abiogenic Hydrocarbons     

Sorokhtin  N. O.  Lobkovsky  L. I.  Kozlov  N. E. 《Oceanology》2020,60(2):248-258

Oceanology - Abstract—The paper studies carbon transformation and transfer processes in the crust and mantle. Sediments dragged into subduction zones are dewatered, broken down, and altered...  相似文献   

Climatology of Precipitation of Different Genesis in Northern Eurasia     

A. V. Chernokulsky  F. A. Kozlov  O. G. Zolina  O. N. Bulygina  V. A. Semenov 《Russian Meteorology and Hydrology》2018,43(7):425-435

A method for discriminating among different types of precipitation is presented. The method is based on surface observations of precipitation, present and past weather, and the morphological types of clouds. The climatology of showery, nonshowery, and drizzle precipitation in Northern Eurasia is studied using the data of 529 Russian weather stations for the period of 1966–2014. Showery precipitation dominates in Northern Eurasia. In general, showery precipitation has greater temporal (monthly and diurnal) and spatial variability than nonshowery precipitation. The majority of showers are registered in summer (the maximum is in July), whereas the high est total monthly nonshowery precipitation is observed in autumn (the maximum is in October). The daily intensity values of showery and nonshowery precipitation are generally close, the maximum intensity is recorded in July–August. For three-hour in tervals, the shower in tensity is by 1.1–1.5 times higher. The drawbacks of the presented methodology are discussed.  相似文献   

Collision metamorphism of precambrian complexes in the Transangarian Yenisei Range     

I. I. Likhanov  V. V. Reverdatto  P. S. Kozlov  N. V. Popov 《Petrology》2008,16(2):136-160

Three complexes in the zones of the Ishimbinskii and Tatarka deep faults in the Transangarian part of the Yenisei Range were studied to reproduce their metamorphic evolution and elucidate distinctive features of regional geodynamic processes. The results of our geological and petrological studies with the application of geothermobarometry and P-T metamorphic paths indicate that the Neoproterozoic kyanite-sillimanite intermediate-pressure metamorphism overprinted regionally metamorphosed rocks of low pressure of Middle Riphean age. The kyanite-sillimanite metamorphism was characterized by (1) the development of deformational structures and textures and kyanite-bearing blastomylonites with sillimanite, garnet, and staurolite after andalusite-bearing regional-metamorphic mineral assemblages; (2) insignificant apparent thickness of the zone of intermediate-pressure zonal metamorphism (from 2.5 to 7 km), which was localized near overthrusts; (3) a low geothermal gradient during metamorphism (from 1–7 to 12°C/km); and (4) a gradual increase in the total metamorphic pressure from southwest to northeast with approaching the overthrusts. These features are typical of collisional metamorphism during the thrusting of continental blocks and testify that the rocks subsided nearly isothermally. The process is justified within the scope of a model for the tectonic thickening of the crust via rapid thrusting and subsequent rapid exhumation and erosion. The analysis of our results with regard for the northeastern dips of the thrusts allowed us to consider the intermediate-pressure metapelites as products of collision metamorphism, which were formed in the process of a single thrusting of ancient rock blocks from the Siberian Platform onto the Yenisei Range.  相似文献   

Spatial pattern of lightning strikes in North Asia     

L. D. Tarabukina  V. I. Kozlov  R. R. Karimov  V. A. Mullayarov 《Russian Meteorology and Hydrology》2017,42(2):88-94

The averaged data of observations oflightning strikes in North Asia in 2009-2014 are presented. The pattern is retrieved from the data of World Wide Lightning Location Network (WWLLN); one station of this network is located in Yakutsk. The dependence of thunderstorm activity on latitude, longitude, and altitude is demonstrated.  相似文献   

Geophysical hydrodynamics of vortical patches     

V. F. Kozlov 《Physical Oceanography》1995,6(1):25-34

This paper reviews the works on vortical patch dynamics, carried out at the Pacific Oceanological Institute, the Russian Academy of Sciences, from 1983 to 1992, as applied to dynamic oceanography modelling. Quasi-geostrophic barotropic and baroclinic models, plane gravitational axisymmetric models, and models considering entrainment effects, are examined.Translated by Vladimir A. Puchkin. UDK 551.465.11.  相似文献