The Triassic stage of mafic magmatism in the Dzhugdzhur–Stanovoi superterrane (southern framing of the North Asian craton)     

I.V. Buchko  A.A. Sorokin  E.B. Sal'nikova  A.B. Kotov  S.D. Velikoslavinskii  A.M. Larin  A.E. Izokh  S.Z. Yakovleva 《Russian Geology and Geophysics》2010,51(11):1157-1166

With U-Pb zircon dating, the ages of the Ul'degit (228 ± 1 Ma) and Chek-Chikan (203 ± 1 Ma) mafic massifs were determined. These massifs were earlier considered to form at the Early Precambrian stage of the geologic evolution of the Dzhugdzhur–Stanovoi superterrane. In geochemical features the igneous rocks of the massifs show relation with a within-plate source, on the one hand, and are similar to igneous rocks of subduction zones, on the other. They might have formed after subduction, which caused the intrusion of gabbroids of the Lucha massif (248 ± 1 Ma) and diorites of the Tok-Algoma complex (238 ± 2 Ma), followed by the fracturing of the subducted plate.  相似文献   

Preliminary determination of the interdependence amongstrong-motion amplitude, earthquake magnitude and hypocentral distance for the Himalayan region     

Imtiyaz A. Parvez  Alexander A. Gusev  Giuliano F. Panza  Anatoly G. Petukhin 《Geophysical Journal International》2001,144(3):577-596

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Geochemical characteristics of mid-ocean ridge basalts     

Shen-Su Sun  Robert W. Nesbitt  Anatoly Ya. Sharaskin 《Earth and Planetary Science Letters》1979,44(1):119-138

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Magnetic resonance sounding applied to aquifer characterization   总被引：3，自引：0，他引：3  

Legchenko A  Baltassat JM  Bobachev A  Martin C  Robain H  Vouillamoz JM 《Ground water》2004,42(3):363-373

Magnetic resonance sounding (MRS) is distinguished from other geophysical tools used for ground water investigation by the fact that it measures a magnetic resonance signal generated directly from subsurface water molecules. An alternating current pulse energizes a wire loop on the ground surface and the MRS signal is generated; subsurface water is indicated, with a high degree of reliability, by nonzero amplitude readings. Measurements with varied pulse magnitudes then reveal the depth and thickness of water saturated layers. The hydraulic conductivity of aquifers can also be estimated using boreholes for calibration. MRS can be used for both predicting the yield of water supply wells and for interpolation between boreholes, thereby reducing the number of holes required for hydrogeological modeling. An example of the practical application of MRS combined with two-dimensional electrical imaging, in the Kerbernez and Kerien catchments area of France, demonstrates the efficiency of the technique.  相似文献   

Paleozoic rocks in infrastructure of the metamorphic core, the Greater Caucasus Main Range zone     

M. L. Somin  A. B. Kotov  E. B. Sal’nikova  O. A. Levchenkov  A. N. Pis’mennyi  S. Z. Yakovleva 《Stratigraphy and Geological Correlation》2006,14(5):475-485

Granitoid orthogneisses and migmatites are widespread in the lower, deeply metamorphosed gneiss-migmatite complex of the pre-Alpine basement (infrastructure) exposed within northern part of the Greater Caucasus Main Range zone. Like the other rocks of the complex, they have been traditionally attributed to the Proterozoic, but the U-Pb dating revealed the Late Paleozoic age of migmatites and Devonian age of orthogneiss protolith. Bodies of blastomylonitic apogranite gneisses, which are confined to boundary between gneiss-migmatite complex and overlying Makera Complex of supracrustal rocks, turned out to be of the Late Paleozoic age as well. The dating results suggest synchronism and, apparently, genetic interrelations between the high-T/low-P metamorphism and granite formation in the Main Range zone of the Greater Caucasus.  相似文献   

Early Cretaceous age of regional metamorphism of the Stanovoi group in the Dzhugdzhur-Stanovoi foldbelt: Geodynamic implications     

A. M. Larin  E. B. Sal&#;nikova  A. B. Kotov  V. A. Glebovitsky  S. D. Velikoslavinsky  A. A. Sorokin  S. Z. Yakovleva  A. M. Fedoseenko  I. V. Anisimova 《Doklady Earth Sciences》2006,409(5):727-731

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Protoliths of the metamorphic rocks of the Fedorov Complex, Aldan shield: Character, age, and geodynamic environments of origin     

S. D. Velikoslavinsky  A. B. Kotov  E. B. Sal’nikova  V. P. Kovach  V. A. Glebovitsky  N. Yu. Zagornaya  S. Z. Yakovleva  E. V. Tolmacheva  I. V. Anisimova  A. M. Fedoseenko 《Petrology》2006,14(1):21-38

Geochemical data indicate that the protoliths of the overwhelming majority of the metamorphic rocks composing the Fedorov Complex in the Aldan granulite megacomplex were volcanic rocks of three groups, which occur in different proportions in the complex: (i) volumetrically predominant (no less than 90%) continuous differentiated island-arc basalt-andesite-dacite-rhyolite series, (ii) within-plate basalts, whose composition was similar to that of low-Ti traps, and (iii) basalts of composition similar to that of continentalrift basalts. The U-Pb zircon crystallization age of the metamorphosed basaltic andesites of the Fedorov Complex was estimated at 2006 ± 3 Ma, which testifies, when considered together with preexisting geochronological data, that the complex was produced during a time span of no longer than 25 m.y. A model is proposed according to which the complex was produced within the geodynamic system of the active continental margin of the Olekma-Aldan continental microplate and the Fedorov island arc.  相似文献   

Towards Calibration of the Mean Magnetic Field of the sun     

V.A. Kotov  S.V. Kotov  V.V. Setyaev 《Solar physics》2002,209(2):233-245

The 1968–2000 data on the mean magnetic field (MMF, longitudinal component) of the Sun are analysed to study long-time trends of the Sun's magnetic field and to check MMF calibration. It is found that, within the error limits, the mean intensity of photospheric magnetic field (the MMF strength, |H|), did not change over the last 33 years. It clearly shows, however, the presence of an 11-year periodicity caused by the solar activity cycle. Time variations of |H| correlate well with those of the radial component, |B _r|, of the interplanetary magnetic field (IMF). This correlation (r=0.69) appears to be significantly higher than that between |B _r| and the results of a potential source-surface extrapolation, to the Earth's orbit, of synoptic magnetic charts of the photosphere (using the so-called `saturation' factor <sup>–1</sup> for magnetograph measurements performed in the line Fei 525.0 nm; Wang and Sheeley, 1995). It seems therefore that the true source surface of IMF is the `quiet' photosphere – background fields and coronal holes, like those for MMF. The average `effective' magnetic strength of the photospheric field is determined to be about 1.9 G. It is also shown that there is an approximate linear relation between |B <sub>r</sub>| and MMF intensity |H| (in gauss)|B <sub>r</sub>|(H <sub>0</sub>)<sub>min</sub>×(1+C|H|)where =1.5×10<sup>–5</sup> normalizes the photospheric field strength to 1 AU distance from the Sun, (H <sub>0</sub>)<sub>min</sub>=1.2 G is some minimal `effective' intensity of photospheric background fields and C=1.3 G^–1 an empirical constant. It is noted that good correlation between time variations of |H| and |B _r| makes suspicious a correction of the photospheric magnetic fields with the use of saturation factor ^–1.  相似文献   

Linearizing the observed power spectrum     

Clay C. Smith  Anatoly Klypin  Michael A. K. Gross  Joel R. Primack  & Jon Holtzman 《Monthly notices of the Royal Astronomical Society》1998,297(3):910-922

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Cold dark matter variant cosmological models — I. Simulations and preliminary comparisons     

Michael A. K. Gross  Rachel S. Somerville  Joel R. Primack  Jon Holtzman  & Anatoly Klypin 《Monthly notices of the Royal Astronomical Society》1998,301(1):81-94

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