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21.
P. G. Korostelev V. G. Gonevchuk B. I. Semenyak N. V. Gorelikova A. A. Karabtsov A. M. Kokorin V. V. Kononov A. A. Orekhov P. P. Safronov E. Ya. Sinyakov 《Geology of Ore Deposits》2009,51(4):305-316
The Dzhalinda wood tin deposit is located at the eastern margin of the Bureya Massif and, according to the Russian classification
of tin deposits, is referred to the rhyolite-hosted type. The Dzhalinda deposit is compared with the deposits located in the
southwestern United States and in northern Mexico. In spite of some similar features, the Dzhalinda deposit differs significantly
from the American deposits in the composition of ore-bearing rhyolite and the type and composition of host rocks. It is suggested
that the ore-bearing rhyolitic melt at the Dzhalinda deposit evolved with the formation of a highly silicic residual melt
depleted in P and Li and enriched in Sn, being opposed in this respect to the ongonite model typical of such deposits. The
drastic change in the physicochemical parameters of the system caused by the evolution of the melt under near-surface conditions
of a volcanic vent led to the separation of Si-Sn complexes, which broke down into various silica modifications and oolite-like
wood tin. 相似文献
22.
The processes of fluid destruction of various silicate rocks under diffusion of flows of compressed gases (mainly carbonaceous) were studied. The gas condensate nature was ascertained for the forming alumoslilicate and ore (cobalt–iron–manganese hydroxide) substances produced under this fluid destruction in the forms of microcrusts and microconcretions. The ore condensates contained in high concentrations the typomorphic elements of oceanic ferromanganese formations (Mn, Co, Ni, Cu, Pb, Ce, and Pt). The elemental composition of the ore oxide substance formed under the destruction of various silicate matrices exhibits a definite degree of endemism with prevalence of the Co–Mn association. The pronounced concentration of barium is related to the substantially carbonaceous composition of the fluid systems. A cerium paradox is revealed: Ce3+ is oxidized into Ce4+ and absorbed by ferromanganese hydrogel and the minimum of cerium appears in rare-earth phosphates. 相似文献
23.
A.E. Kontorovich M.I. Epov L.M. Burshtein V.D. Kaminskii A.R. Kurchikov N.A. Malyshev O.M. Prischepa A.F. Safronov A.V. Stupakova O.I. Suprunenko 《Russian Geology and Geophysics》2010,51(1):3-11
The overall jump in global demand for gas, and especially oil, gives rise to particular concern regarding mankind’s energy future. In the middle and late 21st century, the crucial role in securing oil and gas supply of mankind will be played by sedimentary basins in the Arctic Ocean deep-water area, including those of the continental shelf in Russia’s Arctic seas. There is a 0.90 probability that the initial in-place resources of hydrocarbons in the Arctic Ocean will be greater than 90 Btoe. The estimates predict the rise of oil and gas industries on the Arctic shelves in the near future. 相似文献
24.
S. V. Vysotsky A. V. Barkar V. G. Kuryavy E. A. Chusovitin A. A. Karabtsov P. P. Safronov 《Geology of Ore Deposits》2010,52(8):815-820
The results of the study of hydrothermal noble opal are discussed. it has been established that hydrothermal opal differs
in its nanostructure and formation conditions from exogenic noble opal. The former is composed of smaller globules without
any structuring of closely packed nanoparticles characteristic of exogenic opal. In the course of formation, hydrothermal
opal is affected by pneumatolytic annealing related to the effect of high-temperature vapors under an elevated pressure. At
the same time, the thermal effect results in the formation of two-dimensional photon zones in the chaotic opal matrix. These
photon zones are produced by grids, the cells of which arose from a thermal effect similar to what related to Benard cells.
Precisely, these structured blocks and thin films lead to spectral dispersion of light and appearance of iridescence. 相似文献
25.
Regime observations 017 the zoobenthos state in the Balagansk transect in 1971, 1972 and in the Odissa bay in 1987-1993 of the Bratsk Reservoir were conducted.In 1991-1993 there is a change in the zoobenthos structure of the Bratsk Reservoir. In the depth zone of 0-5 m in the Balagansk transect in 1971-1972 the bottom community was considered as Gammaridae-Chiro-nomodae, in 1991 as Gammaridae-Ephemeroptera in 1992-1993 as Chironomidae-Ephemeroptera-Gammaridae. As compared with 1968-1972 the importance of Gammaridae decreased and the role of Ephemeroptera increased in the zoobenthos structure in 1991-1993.Changes were noted in the species composition of the Ologochaeta fauna and increase of the role of Oligochaeta in the zoobenthos in 1991-1993 as compared with 1965-1972.During all studies Chironomidae played a significant role in the zoobenthos. Since 1989 Paratanytarsus baialensis, bailialian endemic, has occurred in the Chironomidae fauna.The comparison of zoobenthos has shown that aver-age number and biomass of bortom invertebrates by 3-6 times and species diversity by 2.25 are higher^ in the Odissa bay than in the Balagansk transect. 相似文献
26.
27.
A.F. Safronov E.Yu. Shits M.N. Grigor'ev M.E. Semenov 《Russian Geology and Geophysics》2010,51(1):83-87
Natural gas hydrate deposits have been estimated to store about 10% of gas in hydrate form (even with regard to a higher concentration of gas in hydrates), proceeding from the known ratio of dissolved-to-deposited gas. This high percentage is largely due to the fact that the buffer factor in natural gas hydrate deposits is lower than that for free gas because of less diverse structural conditions for gas accumulation. Therefore, the available appraisal of world resources of hydrated gas needs a revision.Hydrates in rocks are either syngenetic or epigenetic. Syngenetic hydrates originate from free or dissolved gas which was present in rocks in situ at the time when PT-conditions became favorable for gas hydrate formation. Epigenetic hydrates are derived from gas which came by migration into rocks with their PT-conditions corresponding to formation of gas hydrates.In addition to the optimum PT-conditions and water salinity, economic gas hydrate accumulation requires sustained supply of natural gas into a specific zone of gas hydrate formation. This condition is feasible only in the case of vertical migration of natural gas along faults, fractured zones, and lithologic windows, or, less often, as a result of lateral migration.Of practical importance are only the gas hydrate deposits produced by vertical or lateral gas migration. 相似文献
28.
N. F. Elansky I. I. Mokhov I. B. Belikov E. V. Berezina A. S. Elokhov V. A. Ivanov N. V. Pankratova O. V. Postylyakov A. N. Safronov A. I. Skorokhod R. A. Shumskii 《Izvestiya Atmospheric and Oceanic Physics》2011,47(6):672-681
In the summer of 2010, the Moscow megacity during two months was within the zone of action of a blocking anticyclone. The accumulation of pollutants in a closed air mass sharply changed the surface air quality. At the end of July-the first half of August, the extreme situation became even more complicated, because the air from regions of turf and grass fires came into Moscow. According to measurement data of the Moscow IAP RAS station, the maximal hourly mean concentrations of chemically active gases NO, NO2, CO, O3, and SO2 were 175.9, 217.4, 15.8, 134.2, and 15.2 ppb, respectively. For NO2 and CO, these values are largest over the entire decadal period of observations at the station and many times exceed the MPC level (see table). The concentrations of greenhouse gases CO2, CH4, and nonmethane hydrocarbons also sharply increased. Analysis of the variability of gas contents in the surface air and in the atmospheric boundary layer showed a close relation between extreme changes in the atmospheric composition and its vertical stratification. 相似文献
29.
A.F. Safronov A.I. Sivtsev O.N. Chalaya I.N. Zueva A.N. Sokolov G.S. Fradkin 《Russian Geology and Geophysics》2013,54(8):997-1000
Formation of the passive continental margin of the Laptev Sea (Laptev Plate), which was part of the Siberian Platform till the Late Cretaceous, was related to the Late Mesozoic–Cenozoic rifting of the Arctic geodepression. The regime of the passive continental margin still continues. The maximum thickness of the deposits of this age seems to exceed 6 km in the northeastern part of the shelf. The hydrocarbon resources of the Late Precambrian–Cenozoic deposits forming the Laptev Plate cover are evaluated. Based on the concept of the similar evolution of the Laptev Plate and Vilyui syneclise, the geochemical characteristics of dispersed organic matter of the coeval deposits of the Vilyui syneclise are used. 相似文献
30.
V. T. Safronov 《Lithology and Mineral Resources》2012,47(3):264-279
The initial normative mineral composition of some metasedimentary rocks (high-alumina crystalline schists, aluminous gneisses,
and eulysites) from the Archean Bol’shoi Cheremshan Group is considered. Based on some data (distribution of data points available
for these rocks in diagnostic diagrams, values of several indicator ratios, and initial rock composition), it is assumed that
examined rocks were partly formed after highly mature sediments (high-alumina crystalline schists and gneisses), while biotite-garnet-andesine
gneisses represent products of graywacke sediments. Elevated concentrations of some indicator elements (Fe, Cr, Ni, V, Zn,
Pb, and others) imply that material in the sedimentation paleobasin was likely derived from provenances composed of variable
lithologies (ultramafic, mafic, intermediate, and acid rocks). It seems that conditions in this paleobasin were favorable
for the development of organic life. It is shown that correlation between some elements (Ti, V vs. Al; Ba, Pb vs. K; Sr vs.
Ca; La vs. Na; and others) typical of Phanerozoic sedimentary rocks is also observed in the rocks. The possible contents of
organic matter (Corg) and U in primary sediments of metasedimentary rocks of the Bol’shoi Cheremshan Group in the East European Platform basement
are reconstructed. 相似文献