Model of Formation of the Sedimentary System of the Eurasian Basin,the Arctic Ocean,as a Basis for Reconstructing Its Tectonic Evolution     

Rekant  P. V.  Petrov  O. V.  Gusev  E. A. 《Geotectonics》2021,55(5):676-696

Geotectonics - For the first time tectonic reconstructions was carried out along the entire seismic dataset, including both Russian and international seismic lines. Based on the analysis of the...  相似文献   

Rb-Sr geochronology of Vendian shales,the Staraya Rechka Formation,Anabar Massif,northern Siberia     

I. M. Gorokhov  M. A. Semikhatov  T. L. Turchenko  P. Yu. Petrov  N. N. Mel’nikov  G. V. Konstantinova  E. P. Kutyavin 《Stratigraphy and Geological Correlation》2010,18(5):480-491

Fine-grained clayey subfractions (SF) with particle sizes of 1–2, 0.6–1.0, 0.3–0.6, 0.2–0.3, 0.1–0.2, and <0.1 μm were extracted from shales of the Vendian Staraya Rechka Formation in the Anabar Massif and studied by XRD and Rb-Sr methods. All the clayey subfractions are represented by illite with high crystallinity indices, which are characteristic of the low-temperature diagenesis/catagenesis zone and grow with the decrease of the particle size. The Rb-Sr systematics in clayey subfractions combined with mineralogical data provide grounds for the conclusion that illite from clayey rocks of the Staraya Rechka Formation was forming during two periods: approximately 560 and 391–413 Ma ago. The first illite generation was likely formed in the course of lithostatic subsidence of the Staraya Rechka sediments and the second one, during the Devonian lithogenesis stage. It is assumed that age of the first generation (∼560 Ma) is close to that of the Staraya Rechka Formation. This inference is consistent with biostratigraphic, chemostratigraphic, and geochronological data obtained for both rocks of the Anabar Massif and Vendian sediments from other regions of Siberia.  相似文献   

Origin of carbonatites of eastern taimyr deduced from an isotopic and geochemical study of zircons     

V. F. Proskurnin  O. V. Petrov  E. A. Bagdasarov  M. I. Rozinov  E. V. Tolmacheva  A. N. Larionov  I. V. Bil’skaya  A. V. Gavrish  I. N. Mozoleva  B. S. Petrushkov 《Geology of Ore Deposits》2010,52(8):711-724

Injection carbonatites of volcanic-plutonic origin with Au-bearing base-metal sulfide mineralization were established in 2006–2007 along the southern slope of the Byrranga Range in the Russian continental sector of the Arctic. According to thermobarogeochemical data, carbonatites were formed at a temperature not lower than 380–410°C from boiling gas-liquid H₂O-CO₂-salt fluids under decompression. The REE concentrations and patterns of sedimentary and magmatic carbonates are sharply distinct. Carbonatites are enriched in REE as compared to carbonates from limestone and are characterized by an REE distribution close to MORB. The geochronological and isotopic geochemical study of zircons has shown that carbonatite bodies (lavas?) were formed 238–219 Ma ago (Middle-Late Triassic); zircon crystallized at a high temperature. Detrital zircons from the Lower Carboniferous crinoid limestone are not younger than 594 Ma. The absolute predominance of Precambrian zircons, which are variable in age, indicates that they were captured from the crust, when carbonatitic magma ascended from subcrustal depths.  相似文献   

Modern conception of meteorological protection of megalopolises using cloud seeding methods     

B. P. Koloskov  V. P. Korneev  V. V. Petrov  G. P. Beryulev  B. G. Danelyan 《Russian Meteorology and Hydrology》2010,35(8):515-523

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Experimental study of charge vertical transfer in surface air layer     

I.?N.?Panchishkina  G.?G.?PetrovaEmail author  A.?I.?Petrov 《Geomagnetism and Aeronomy》2017,57(3):347-351

The variability of air–earth electric currents in the lower 3-m air layer is analyzed in a complex with measurement data on the physical parameters that affect charge transfer in the atmosphere. Three types of air–earth current density profiles have been revealed during experimental observations in summer in Rostov region: (1) the current density decreases with an increase in the distance from the Earth’s surface and then stabilizes (nighttime conditions); (2) the current density increases with altitude up to 1 m and then decreases as altitude increases (day hours); (3) transient between types 1 and 2 that are observed in the morning and evening hours. The intensity of charge transfer in the surface air layer under the action of mechanical forces under different stratifications is estimated on the basis of data on altitude variations in the air–earth current density in view of the stationarity of electric processes and the constancy in the altitude of the total air–earth current density. Thermodynamic conditions are estimated with the use of wind velocity measurements and calculations of the turbulence factor and vertical component of the air temperature gradient.  相似文献   

Observations and light curve solutions of a selection of middle-contact W UMa binaries     

Diana Petrova Kjurkchieva  Velimir Angelov Popov  Doroteya Lyubenova Vasileva  Nikola Ivanov Petrov 《天文和天体物理学研究(英文版)》2018,(4)

Photometric observations in Sloan g′and i′ bands of W UMa binaries NSVS 4340949,T-Dra0–00959,GSC 03950–00707,NSVS 4665041,NSVS 4803568,MM Peg,MM Com and NSVS4751449 are presented.The light curve solutions revealed that the components of each target are of G and K spectral types.The binaries of the sample have middle-contact configurations whose fillout factors are within the range 0.2–0.4.The only exception is NSVS 4751449 which is in deeper contact(fillout factor of 0.55).It precisely obeys the relation between mass ratio and fillout factor for deep,low mass ratio overcontact binaries.One of the eclipses of almost all targets(except MM Peg)is an occultation and their photometric mass ratios and solutions could be accepted with confidence.We found that the target components have almost equal temperatures but differ considerably in size and mass.The components of the partially-eclipsed MM Peg have close parameters.Our solutions reveal that NSVS 4340949,T-Dra0–00959,NSVS 4803568 and MM Com are of W subtype while GSC 03950–00707,NSVS 4665041,MM Peg and NSVS 4751449 are of A subtype.This subclassification is well-determined for all totallyeclipsed binaries.The targets confirm the trends in which W-subtype systems have smaller periods and lower temperatures than A subtype binaries.  相似文献   

On Errors in Constructing the Polarization Phase Dependences for Solar System Bodies     

N. N. Kiselev  D. V. Petrov 《Solar System Research》2018,52(3):282-285

In astrophysical studies of Solar System bodies, the measured values of the linear polarization degree P_obs and the position angle of the polarization plane θ are usually considered relative to the plane orthogonal to the scattering plane; and the resulting quantities are designated as P_r and θ_r, respectively. Parameters of the phase curve of polarization P_r = f(α) serve for determining the physical characteristics of grains composing the regolith surfaces of such bodies as, for example, the Moon, Mercury, asteroids, and planetary satellites, or the polydisperse media, such as cometary comae and tails. In this paper it has been shown that the error in the polarization degree grows \({\sigma _{{P_r}}}\) due to the error \({\sigma _{{\theta _{obs}}}}\) in determining the position angle. The interrelations between these errors were obtained, and the conditions, under which the values of the linear polarization degree P_r relative to the orthogonal system can be used to analyze the phase dependences of polarization, were formulated.  相似文献   

The planet formation imager     

John D. Monnier  Stefan Kraus  Michael J. Ireland  Fabien Baron  Amelia Bayo  Jean-Philippe Berger  Michelle Creech-Eakman  Ruobing Dong  Gaspard Duchêne  Catherine Espaillat  Chris Haniff  Sebastian Hönig  Andrea Isella  Attila Juhasz  Lucas Labadie  Sylvestre Lacour  Stephanie Leifer  Antoine Merand  Ernest Michael  Stefano Minardi  Christoph Mordasini  David Mozurkewich  Johan Olofsson  Claudia Paladini  Romain Petrov  Jörg-Uwe Pott  Stephen Ridgway  Stephen Rinehart  Keivan Stassun  Jean Surdej  Theo ten Brummelaar  Neal Turner  Peter Tuthill  Kerry Vahala  Gerard van Belle  Gautam Vasisht  Ed Wishnow  John Young  Zhaohuan Zhu 《Experimental Astronomy》2018,46(3):517-529

The Planet Formation Imager (PFI, www.planetformationimager.org) is a next-generation infrared interferometer array with the primary goal of imaging the active phases of planet formation in nearby star forming regions. PFI will be sensitive to warm dust emission using mid-infrared capabilities made possible by precise fringe tracking in the near-infrared. An L/M band combiner will be especially sensitive to thermal emission from young exoplanets (and their disks) with a high spectral resolution mode to probe the kinematics of CO and H₂O gas. In this paper, we give an overview of the main science goals of PFI, define a baseline PFI architecture that can achieve those goals, point at remaining technical challenges, and suggest activities today that will help make the Planet Formation Imager facility a reality.  相似文献   

Precise geodesy with the Very Long Baseline Array   总被引：2，自引：2，他引：0  

Leonid Petrov  David Gordon  John Gipson  Dan MacMillan  Chopo Ma  Ed Fomalont  R. Craig Walker  Claudia Carabajal 《Journal of Geodesy》2009,83(9):859-876

We report on a program of geodetic measurements between 1994 and 2007 which used the Very Long Baseline Array (VLBA) and up to ten globally distributed antennas. One of the goals of this program was to monitor positions of the array at a 1 mm level of accuracy and to tie the VLBA into the international terrestrial reference frame. We describe the analysis of these data and report several interesting geophysical results including measured station displacements due to crustal motion, earthquakes, and antenna tilt. In terms of both formal errors and observed scatter, these sessions are among the very best geodetic very long baseline interferometry experiments.  相似文献   

Star burst activity in high surface brightness galaxies     

G. T. Petrov 《Astrophysics and Space Science》1989,151(1):169-175

High surface brightness galaxies are also galaxies with high star-forming activity. About a half of them omit, on the average, twice as much energy in the IR than in the blue. The rates of star formation are 10–30 times higher than those in normal galaxies. On average 100–300 solar masses gas are converted into stars every year and 10–30 are massive stars.  相似文献