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1.
Doklady Earth Sciences - Experimental data on the Nb, Ta, Ti, Ce, and La concentrations in felsic magmatic melts of various alkalinity and alumina content upon dissolving ilmenorutile,... 相似文献
2.
Doklady Earth Sciences - Two varieties of highly differentiated topaz-bearing granite of the Salmi Batholith are distinguished: Li-siderophyllite topaz-bearing granite (Li-Sdph) (Lupikko dome) and... 相似文献
3.
HST trigonometric distances, photometric metallicities, isochronic ages from the second revised version of the Geneva-Copenhagen
survey, and uniform spectroscopic Fe and Mg abundances from our master catalog are used to construct and analyze the age-metallicity
and age-relative Mg abundance relations for stars of the thin disk. The influences of selection effects are discussed in detail.
It is demonstrated that the radial migration of stars does not lead to appreciable distortions in the age dependence of the
metallicity. During the first several billion years of the formation of the thin disk, the interstellarmaterial in this disk
was, on average, fairly rich in heavy elements (〈[Fe/H]〉 ≈ −0.2) and poorly mixed. However, the metallicity dispersion continuously
decreased with age, from σ
[Fe/H] ≈ 0.22 to ≈0.13. All this time, the mean relative abundance of Mg was somewhat higher than the solar value (〈[Mg/Fe]〉 ≈ 0.1).
Roughly four to five billion years ago, the mean metallicity began to systematically increase, while retaining the same dispersion;
the mean relative Mg abundance began to decrease immediately following this. The number of stars in this subsystem increased
sharply at the same time. These properties suggest that the star-formation rate was low in the initial stage of formation
of the thin disk, but abruptly increased about four to five billion years ago. 相似文献
4.
The thickness of the mixed bottom boundary layer (BBL) has been analyzed based on the CTD data at transoceanic sections in abyssal waters of the Northern Atlantic. The measurements were carried out at two transoceanic sections approximately along 48° N (ASV-99) and 5° N (AI-2000) in 1999 and 2000. These data, and the WOCE data obtained at four zonal sections (AR7E and AR12 along 57° N, AR01 along 24.5° S, and A06 along 7.5° N), were used for the calculation of the statistical characteristics of the BBL??s thickness H B . The probability distribution function F(H B ) was close to lognormal. The mean value ??H B ?? at different latitudes was in the range from 30 to 60 m. The averaged BBL thickness = 46.1 m. The BBL??s thickness was about 1% of the ocean??s depth D; the ratio H B /D was the minimum (0.8%) near the equator and increased up to 1.6% in the polar latitudes. 相似文献
5.
Gorbachev N. S. Kostyuk A. V. Shapovalov Yu. B. Gorbachev P. N. Nekrasov A. N. Soultanov D. M. 《Doklady Earth Sciences》2019,489(2):1421-1425
Doklady Earth Sciences - The phase relations upon eclogitization of basalt and melting of H2O-bearing eclogite were studied experimentally for basalt–H2O in the range of P = 3.7–4.0 GPa... 相似文献
6.
Butvina V. G. Vorobey S. S. Safonov O. G. Varlamov D. A. Bondarenko G. V. Shapovalov Yu. B. 《Doklady Earth Sciences》2019,486(2):711-715
Doklady Earth Sciences - The results of experiments on the synthesis of exotic titanates (priderite and yimengite) simulating metasomatic conditions of alteration of the mantle minerals (chromite... 相似文献
7.
Gorbachev N. S. Kostyuk A. V. Shapovalov Yu. B. Gorbachev P. N. Nekrasov A. N. Soultanov D. M. 《Doklady Earth Sciences》2019,488(2):1240-1244
Doklady Earth Sciences - Phase relations in the phlogopite–carbonate system were studied at P = 3.8 GPa and T = 1200–1300°C. The interaction of phlogopite with the carbonate melt... 相似文献
8.
Doklady Earth Sciences - The data of experiments are presented on the Ta and Nb concentrations in acidic magma melts of various compositions upon dissolution of pyrochlore and microlite at... 相似文献
9.
T. V. Setkova V. S. Balitsky O. S. Vereschagin Yu. B. Shapovalov 《Doklady Earth Sciences》2017,473(2):419-422
Ga-bearing tourmaline was originally synthesized in boron, boron–alkaline, and boron–fluorine hydrothermal solutions at a temperature of 600–650°C and pressure of 100 MPa as crystals of spontaneous growth and on seeds. The maximal concentration of Ga2O3 in synthetic crystals reaches ~24.5 wt %. In addition to Ga-bearing tourmaline, Ga-bearing topaz crystallizes in boron–fluorine solution. Ga-bearing albite crystallizes in boron–alkaline solutions, whereas no additional phases are formed in pure boron solutions. 相似文献
10.
V. Yu. Chevychelov A. A. Korneeva A. A. Virus Yu. B. Shapovalov 《Doklady Earth Sciences》2017,473(2):454-456
The solubility of H2O–CO2–Cl-containing fluids of various concentrations (0, 3, 10, and 23 wt % of HCl and from 0 to ~8–15 wt % of CO2) in dacite, phonolite, and rhyolite melts at 1000°C and 200 MPa was studied in experiments. It was shown that the Cl concentration in the melt increased substantially from rhyolite to phonolite and dacite (up to 0.25, 0.85, and 1.2 wt %, respectively). The introduction of CO2 into the system resulted in an increase in the Cl content in the melt composition by 20–25%. One may suppose that Cl reactivity in a fluid increases in the presence of CO2 to cause growth of the Cl content in the melt. The introduction of CO2 into the system considerably affects the content of H2O in aluminosilicate melts as well. Thus, the addition of CO2 decreases the H2O content in the melt by ~0.5–1.0 wt %. The decrease in the H2O content in an aluminosilicate melt is probably caused by fluid dilution with CO2 resulting in a decrease in the H2O mole fraction and fugacity in the fluid. 相似文献