Formation stages of the large-scale noble metal mineralization in the Sukhoi Log deposit,east Siberia: Results of isotope-geochronological study     

N. P. Laverov  I. V. Chernyshev  A. V. Chugaev  E. D. Bairova  Yu. V. Gol’tsman  V. V. Distler  M. A. Yudovskaya 《Doklady Earth Sciences》2007,415(1):810-814

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A new type of large-scale manifestation of within-plate intrusive trap magmatism (West Siberian Craton)     

Yu. R. Vasil’ev  S. N. Prusskaya  M. P. Mazurov 《Doklady Earth Sciences》2007,413(1):187-191

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Raman spectroscopy of nanocrystals in rock     

G. A. Sobolev  V. I. Vettegren  S. M. Kireenkova  V. B. Kulik  Yu. A. Morozov  A. I. Smul’skaya 《Izvestiya Physics of the Solid Earth》2007,43(6):447-454

Nanocrystals were detected and identified in rocks by the method of Raman spectroscopy. The experiments showed that the Raman scattering spectra of fine-lamellar arkosic sandstone exhibit bands corresponding to lattice vibrations of anatase, α-quartz, and plagioclase. In all spectra of the rock, the bands are displaced towards high frequencies as compared with their position in spectra of single crystals and widen on the same side. These results show that, in all of the studied places of the sample, the particles of anatase, quartz, and plagioclase have nanometer sizes, namely, of the order of 10 nm in anatase and quartz and about 20 nm in plagioclase. Moreover, in different places of the sample, not only the shape and position of the bands under study but also their intensity vary, the latter being directly proportional to the concentration of nanocrystals.  相似文献   

Isotopic-geochemical signs of coal and bitumen transformation in different-type ore mineralization: Communication 1. Isotopic-geochemical signs of structural transformation of coal and bitumen     

E. D. Syngaevskii  Yu. V. Shchegol’kov  G. Ch. Vitozhents  G. K. Khachatryan  S. N. Petrova 《Lithology and Mineral Resources》2007,42(5):420-436

Results of the study of natural organic matter (OM) represented by classes of solid and high-molecular-compounds (resin, ozokerite, asphalt, kerite, graphite, and others) are presented. They are developed as dispersed and concentrated segregations, interlayers, and independent accumulations and impregnation in the fracture-vein system and stratiform bodies. They also accompany ore mineralization. Combination of modern tic mineralogical, chemical, isotopic, infrared spectroscopic, and X-ray photoelectron spectroscopic) analytical methods provide insight into the OM transformation during oil formation and ore genesis. Variations in OM composition and properties define the concentration of ore elements and change mechanisms of their fixation (sorption, chemosorption, and reduction). Isotopic-geochemical signs of the structural transformation of Coal and bitumen allow us to elaborate a unified scale of catagenesis and metamorphism of the sapropel-and humus-type OM.  相似文献   

An immersed boundary method for compressible multiphase flows: application to the dynamics of pyroclastic density currents     

Mattia de’ Michieli Vitturi  Tomaso Esposti Ongaro  Augusto Neri  Maria Vittoria Salvetti  François Beux 《Computational Geosciences》2007,11(3):183-198

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Ore mineralization related to the zone of the pre-Riphean structural-stratigraphic unconformity and Lower Riphean platform cover of the Uchur-Maya depression, the southeastern Siberian Platform     

M. V. Goroshko  V. A. Gur’yanov 《Russian Journal of Pacific Geology》2007,1(6):586-601

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Numerical modeling of the evolution of unstable modes of jets from young stellar objects     

N. M. Kuz’min  V. V. Mustsevoi  S. S. Khrapov 《Astronomy Reports》2007,51(12):985-993

We present the results of numerical simulations of radiating nodes in jets outflowing from young stellar objects. The development of the fundamental and first reflection harmonics of the jet during the essentially non-linear stage is considered. We have shown for the first time the possible formation of radiating nodes with diameters smaller than the jet cross section. We describe our numerical code, which makes it possible for this class of problem to maintain a stationary equilibrium in the radial coordinate and minimize the force imbalance resulting from the transfer of stationary distributions along the meridian coordinate in the computational grid.  相似文献   

Geology, mineralogy, and PGE mineralization of the copper-nickel occurrences of the Kvinum ore field, Sredinny Range, Kamchatka     

I. A. Tararin  V. M. Chubarov  E. K. Ignat’ev  S. V. Moskaleva 《Russian Journal of Pacific Geology》2007,1(1):82-97

The geology and mineralogy of host metamorphic rocks, the mineralogy of sulfide ores, and the distribution of PGE mineralization were studied in detail for the Kvinum-1 and Kvinum-2 copper-nickel occurrences of the Kvinum ore field, which are the most promising targets for the copper-nickel-PGE mineralization of the Sredinny Range of Kamchatka. It was established that stringer-disseminated and massive copper-nickel ores are localized in amphibole peridotites, cortlandites, and form ore bodies varying from tens of centimeters to 5–20 m thick among the layered cortlandite-gabbroid massifs. The massive sulfide ores were found only at the bottom of cortlandite bodies and upsection grade into stringer-disseminated and disseminated ores. Pyrrhotite, chalcopyrite, and pentlandite are the major ore minerals with a sharply subordinate amount of pyrite, sphalerite, galena, arsenopyrite, and löllingite. Besides pentlandite, the Ni-bearing minerals include sulforasenides (gersdorffite), arsenides (nickeline), and tellurides (melonite) of nickel. It was found that PGE mineralization represented by antimonides (sudburyite) and tellurobismuthides (michenerite) of Pd with sharply subordinate platinum arsenide (sperrylite) is confined to the apical parts of massive sulfide zones and the transition zone to the stringer-disseminated ores. Ore intervals enriched in arsenides and tellurides of Ni, Pd, and Bi contain high-purity gold. In the central parts of the orebodies, the contents of PGE and native gold are insignificant. It is suggested that the contents of major sulfide minerals and the productivity of PGE mineralization in the cortlandites are defined by combined differentiation and sulfurization of ultramafic derivatives under the effect of fluids, which are accumulated at the crystallization front and cause layering of parental magmas with different sulfur contents. The fluid-assisted layering of mafic-ultramafic massifs resulted in the contrasting distribution of PGM in response to uneven distribution of sulfur (as well as As, Te, and Bi) during liquid immiscibility. The productivity of PGE mineralization significantly increases with increasing contents of S, As, Te, and Bi (elements to which Pt and, especially, Pd have high affinity) in fluids.  相似文献   

Gravitational model of the Taiwan lithosphere (along the profile Taiwan Strait-Taiwan Island-West Philippine basin)     

G. Z. Gil’manova  V. Ya. Podgornyi 《Russian Journal of Pacific Geology》2007,1(3):230-239

Based on two-dimensional gravity modeling, the density section of the lithosphere beneath Taiwan and the surrounding areas is constructed. According to the density parameters, the lithosphere of this region comprises both the continental and oceanic types. The continental lithosphere is lighter than the oceanic one and demonstrates insignificant density differentiation through the entire section. The oceanic lithosphere is more contrasting with respect of both the crust and mantle density. The complicated Taiwan density structure corresponding to Taiwan Island is defined to be superimposed on the transition zone between the continental and oceanic lithospheric blocks. This structure with contrasting density boundaries is characterized by the elevated and high density values of its constituting heterogeneities. The formation of the Taiwan density structure is related to geodynamic processes in the Taiwan area marking the collision zone between the Eurasian and Philippine Sea plates.  相似文献   

First Th-U-Pb single zircon dating of metasomatites from the Belomorian mobile belt     

N. S. Serebryakov  B. Yu. Astaf’ev  O. A. Voinova  S. L. Presnyakov 《Doklady Earth Sciences》2007,413(2):388-392

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