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Nakamura Hitomi Iwamori Hikaru Morikawa Noritoshi Kharitonova Natalia Chelnokov Georgy Bragin Ivan Chang Qing 《Aquatic Geochemistry》2021,27(4):269-282
Aquatic Geochemistry - Spring waters with high-pCO2 content are widely distributed in the Sikhote-Alin region in Russia. Mukhen spa is one such spring located in the northern Sikhote-Alin region.... 相似文献
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Oleg G. Safonov Elizaveta I. Kovaleva Svetlana A. Kosova H.M. Rajesh Georgy A. Belyanin Maria A. Golunova Dirk D. Van Reenen 《地学前缘(英文版)》2012,3(6):829-841
Reaction textures and fluid inclusions in the~2.0 Ga pyroxene-bearing dehydration zones within the Sand River biotite-hornblende orthogneisses(Central Zone of the Limpopo Complex) suggest that the formation of these zones is a result of close interplay between dehydration process along ductile shear zones triggered by H2O-CO2-salt fluids at 750—800℃and 5.5—6.2 kbar.partial melting,and later exsolution of residual brine and H2O-CO2 fluids during melt crystallization at 650—700℃.These processes caused local variations of water and alkali activity in the fluids,resulting in various mineral assemblages within the dehydration zone.The petrological observations are substantiated by experiments on the interaction of the Sand River gneiss with the H2O-CO-2-(K,Na)Cl fluids at 750 and 800℃and 5.5 kbar.It follows that the interaction of biotite-amphibole gneiss with H2O-CO2-(K.Na)Cl fluids is accompanied by partial melting at 750—800℃.Orthopyroxene-bearing assemblages are characteristic for temperature 800℃and are stable in equilibrium with fluids with low salt concentrations,while salt-rich fluids produce clinopyroxene-bearing assemblages.These observations arc in good agreement with the petrological data on the dehydration zones within the Sand River orthoeneisses. 相似文献
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Georgy S. Golitsyn 《Boundary-Layer Meteorology》2009,132(2):185-191
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In order to develop a model for simulating naturally occurring chromian spinel compositions, we have processed published
experimental data on chromian spinel-melt equilibrium. Out of 259 co-existing spinel-melt experiments reported in the literature,
we have selected 118 compositions on the basis of run time, melt composition and experimental technique. These data cover
a range of temperatures 1150–1500° C, oxygen fugacities of −13<log f
O2< −0.7, and bulk compositions ranging from basalt and norite, to komatiite. Six major spinel components with Cr3+, Al3+, Ti4+, Mg2+, Fe3+ and Fe2+-bearing end-members were considered for the purpose of describing chromite saturation as a function of melt composition,
temperature and oxygen fugacity at 1 atmosphere pressure (0.101 MPa). The empirically calibrated mineral-melt expression based
on multiple linear regressions is:
K
Sp
i
=A/T(K)+B log f
O2+C ln (Fe3+/Fe2+)L+D ln R
L
+E,
where K
Sp
i
is an equilibrium constant and R
L
is a melt structure-chemical parameter (MSCP). Twenty-eight forms of equilibrium constants were considered, including single distribution coefficients, exchange equilibrium
constants, formation constants for AB2O4 components, as well as simple “spinel cation ratios”. For each form of the equilibrium constants, a set of 16 combinations
of the MSCPs have been investigated. The MSCP is present in the form of composite ratios [e.g., Si/O, NBO/T,(Al+Si)/Si, or (Na+K)/Al] or as simple cation ratios (e.g.,
Mg/Fe2+). For the calculation of Fe3+ and Fe2+ species in silicate melts, we used existing equations, whereas the Fe3+/Fe2+ ratio of spinels was calculated from the spinel stoichiometry. The regression parameters that best repoduce the experimental
data were for the following constants: (Fe3+/Fe2+)
Sp
, (Mg/Fe2+)
Sp
/(Mg/Fe2+)
L
, (Cr/Al)
Sp
/ (Cr/Al)
L
, K
FeCr2O4, and Ti
Sp
/Ti
L
. These expressions have been combined into a single program called SPINMELT, which calculates chromite crystallization temperature
and composition at a given f
O2 with an average accuracy of ∼10° C and 1–2 mol%. An example of the use of SPINMELT is presented for a magma parental to the
Bushveld Complex.
Received: 30 May 1995/Accepted: 1 November 1995 相似文献
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Georgy P. Gladyshev 《Earth, Moon, and Planets》1978,19(1):89-98
The present study develops a previously suggested physico-chemical theory, according to which the regular structure of planetary and satellite systems is explained on the basis of notions regarding periodic condensation of gaseous matter in space and time during formation of the centre body. The author examines specific chemical transformation models that may have been determinative factors in the formation of primary rings of planetary systems. A simplified model is based on the concept that condensed iron compounds, which formed as a result of reactions between the protocloud (protodisk) matter and iron carbonyl hydrides diffusing from the neighbourhood of the centre body, were essentially the primary ring embryos. A concept has been suggested according to which optically active substances (stereoisomers) can form in protoplanetary clouds in the magnetic and gravitational fields of centre bodies. 相似文献
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Georgy Gladyshev 《Earth, Moon, and Planets》1978,18(2):217-221
The planets and their satellites are formed in accordance with similar mechanisms as a result of spatially periodic condensation of gaseous matter during the formation of the central body.Using the diffusion theory one can calculate the age of the planets and explain the nature of the Titius-Bode law. 相似文献
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Marina G. Persova Yuri G. Soloveichik Georgy M. Trigubovich Denis V. Vagin Petr A. Domnikov 《Geophysical Prospecting》2014,62(5):1193-1201
A large closed wire loop is generally used in field experiments for testing airborne electrical exploration equipment. Thus, methods are required for the precise calculation of an electromagnetic response in the presence of a closed wire loop. We develop a fast and precise scheme for calculating the transient response for such a closed loop laid out at the surface of a horizontally layered conductive ground. Our scheme is based on the relationship between the magnetic flux flowing through a closed loop and the current induced in it. The developed scheme is compared with 2D and 3D finite‐element modelling for several positions of an airborne electromagnetic system flying over a closed loop. We also study the coupling effect between the current flowing in the closed loop and the current flowing in the horizontally layered conductive medium. The result shows that for the central position of the transmitter, the difference between axisymmetrical finite‐element modelling and our scheme is less than 1%. Moreover, for the non‐coaxial transmitter–receiver–loop system, the solution obtained by our scheme is in good agreement with full 3D finite‐element modelling, and our total simulation time is substantially lower: 1 minute versus 120 hours. 相似文献
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Georgy Shevchenko Alexander Shishkin Grigory Bogdanov Artem Loskutov 《Pure and Applied Geophysics》2011,168(11):2011-2021
Bottom pressure gauges deployed in bays of Shikotan Island (South Kuril Islands) recently recorded two tsunamis: the Simushir
(Kuril Islands) tsunami of January 13, 2007 generated by a local earthquake with magnitude M
w = 8.1 and the Peruvian tsunami of August 15, 2007 generated by a distant earthquake, M
w = 8.0. The records enabled us to investigate the properties of these two tsunamis and to estimate the effect of the regional
and nearshore topography on arriving tsunami waves. Eigen periods and spatial structure of resonant oscillations in particular
bays were examined based on results of numerical modeling. Significant amplification of the fundamental (Helmholtz) resonant
modes in Malokurilskaya Bay (19 min) and in Krabovaya Inlet (29 min) and some secondary modes was caused by the Simushir tsunami.
The considerably different geometry and bottom topography of these bays, located on the inner coast of the island, determine
the differences in their eigen periods; the only mutual peak, which was found in both basins, had a period of 5 min and was
probably related to the source features. The Peruvian tsunami was clearly recorded by the bottom pressure gauge in Tserkovnaya
Bay on the outer (oceanic) coast of the island. Three dominant periods in the tsunami spectrum at this bay were 60, 30 and
19 min; the latter period was found to be related to the fundamental mode of the bay, while the other two periods appear to
be associated with the shelf resonant amplification of tsunami waves arriving in the region of the South Kuril Islands. The
prevalence of low-frequency components in the observed tsunami spectrum is probably associated with the large extension of
the initial source area and faster decay of short period waves during the long trans-oceanic tsunami propagation. 相似文献