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451.
Dr. M. Shimizu Dr. C. J. Stanley Dr. A. J. Criddle Dr. A. Kato Dr. S. Matsubara 《Mineralogy and Petrology》1991,45(1):11-17
Summary New compositional and optical data are reported for antimonian and antimonianbismuthian varieties of hemusite from epithermal Au-Ag-Cu deposits in Japan. The empirical formula for the antimonian variety, from the Iriki mine is: (Cu5.83Fe0.14Ag0.01)5.98Mo1.03(Sn0.54Sb0.41Te0.03Bi0.02)1.00(S7.85Se0.15)8.00, and that of the Sb-Bi variety from the Kawazu mine is: (Cu5.84Fe0.14Ag0.01)5.99Mo1.03(Sn0.82Sb0.11Bi0.l0Te0.04)1.07(S7.80Se0.12)7.92. The theoretical formula of hemusite is Cu+
4Cu2+
2MO4+Sn4+S8, whilst the most probable formula of the Iriki hemusite is Cu+
4.5CU2+
1.5Mo4+Sn4+
0.5Sb5+
0.5S8, with Sb5+ substituting for Sn4+ and forming (SbS4)3– tetrahedra as might be expected, given that the metal to sulphur ratio is 1, and given the sphalerite-like structure of the mineral. However Bi3+ cannot be so accommodated, resulting in a deficiency in (S + Se) for Kawazu hemusite. Reflectance spectra for both are compared with those of the tungsten analogue (compositional) of hemusite, kiddcreekite. The relationship between hemusitesensu stricto and these newly reported varieties is discussed in terms of simple and coupled chemical substitutions, and inferences are drawn on the valency of Sb, Bi, Mo and Cu in the hemusite structure.
Neue chemische und optische Daten für antimon- und bismuthführende Varietäten von Hemusit aus Japan
Zusammenfassung Neue chemische und optische Daten für antimon- und bismuthführende Hemusite auf epithermalen Au-Ag-Cu Lagerstätten in Japan werden vorgelegt. Die empirische Formel für die antimon-führende Varietät aus der Iriki-Mine ist: (Cu5.83Fe0.14Ag0.01)5.98Mo1.03(Sn0.54Sb0.41Te0.03Bi0.02)1.00 (S7.85Se0.15)8.00, und die der Sb-Bi Varietät aus der Kawazu Mine ist: (Cu5.84Fe0.14Ag0.01)5.99M01.03(Sn0.82Sb0.11Bi0.l0Te0.04)1.07 (S7.80Se0.12)7.92. Die theoretische Formel von Hemusit ist Cu+ 4Cu2+ 2Mo4+Sn4+S8, während die wahrscheinlichere Formel für den Hemusit von Iriki Cu+ 4Cu2+ 1.5Mo4+Sn4+ 0.5Sb5+ 0.5S8, mit Sb5+ an der Stelle von Sn4+, das(SbS4)3– Tetraeder bildet, wie zu erwarten ist, unter der Voraussetzung, da das Metall zu Schwefelverhältnis 1 und die Struktur sphaleritähnlich ist. Bi3+ kann jedoch nicht in dieser Weise untergebracht werden, und das führt zu einem Mangel an (S + Se) für den Hemusit von Kawazu. Die Reflektions-Spektren beider Minerale werden mit denen des Wolfram-Equivalents von Hemusit (Kiddcreekit) verglichen. Die Beziehung zwischen Hemusitsensu stricto und diesen jetzt beschriebenen Varietäten wird auf der Basis einfacher und gekoppelter chemischer Substitution diskutiert. Auf dieser Basis werden Schlüsse auf die Valenz von Sb, Bi Mo und Cu in der Hemusit-Struktur gezogen.相似文献
452.
Ongonite from Ongon Khairkhan,Mongolia 总被引:2,自引:0,他引:2
Doz. Dr. M. Štemprok 《Mineralogy and Petrology》1991,43(4):255-273
Summary Albite-topaz kerotophyres, termed ongonites, were discovered byV. I. Kovalenko and coworkers at Ongon Khairkhan in Mongolia in 1970. The type area was revisited, described, resampled, the new data is compared with the earlier data and that from similar rocks elsewhere (Beauvoir and Cinovec granites; Macusani glass).Ongonites are fluorine-rich peraluminous sodic two feldspar granitoids with orthoclase and albite phenocrysts, high modal and normative albite content and the presence of topaz as common accessory mineral. They contain variable amounts of lithium micas or muscovite. Chemically, ongonite is similar to highly fractionated S-type or ilmenite series granitoids. In the type area, F-rich water-poor ongonite melts have intruded to a high crustal level.Ongonite displays a long history of subsolidus reactions and hydrothermal alteration. The hydrothermal alteration may be linked to a spatially associated quartz-wolframite stockwork not genetically related to ongonite. Ongonite has a low W content and an elevated Sn content despite a lack of association with Sn deposits.
Ongonite von Ongon Khairkhan, Mongolei
Zusammenfassung Albit-Topas-Keratophyre, auch als Ongonite bezeichnet, wurden 1970 von V. E. Kowalenko und Mitarbeitern bei Ongon Khairkhan in der Mongolei entdeckt. Die TypLokalität wurde beschrieben und beprobt und die neuen Daten werden mit den früher erhaltenen, und denen von ähnlichen Gesteinen in anderen Bereichen (die Granite von Beauvoir und Cinovec, das Glas von Macusani) verglichen.Ongonite sind Fluor- und Aluminiumreiche (Peraluminous), zwei-Feldspat-Natriumgranitoide mit idiomorphen Orthoklasen und Albit, hohem modalem und normativem Albitgehalt, und Topas als verbreitetem Nebenmineral. Sie führen wechselnde Gehalte von Lithiumglimmern oder Muskovit. Chemisch sind Ongonite stark fraktionierten S-Typ Granitoiden vergleichbar oder auch Granitoiden der Ilmenit-Serie. Im Gebiet der Typlokalität sind fluorreiche wasserarme Ongonit-Schmelzen in ein hohes Krustenniveau intrudiert worden.Ongonite zeigen eine lange Geschichte von Subsolidusreaktionen und hydrothermaler Umwandlung. Die hydrothermale Umwandlung kann mit einem räumlich assoziiertem Quarz-Wolframit Stockwerk in Beziehung gesetzt werden, das genetisch nicht mit den Ongoniten zusammenhängt. Ongonit hat einen niedrigen Wolframgehalt und einen erhöhten Zinngehalt, obwohl keine Assoziation mit Zinnlagerstätten zu beobachten ist.相似文献
453.
Sublethal abnormalities were examined in developing embryos of the winter flounder,Pseudopleuronectes americanus, as part of a study of its early reproductive success in Long Island Sound and two sites in Boston Harbor. These sites represented varying levels of anthropogenic contamination that were possibly affecting reproduction, as ascertained by chromosomal abnormalities and lowered developmental rates in the embryos. Effort was focused on examination of blastula and tail-bund embryos from field-captured females spawned at the laboratory. Abnormalities observed included evidence of cytotoxicity and chromosome damage. Embryos of fish from New Haven were usually the most aberrant, while embryos from other sites, notably Hempstead, Shoreham, and both Boston Harbor stations, showed subtle indications of abnormality. 相似文献
454.
The influence of compressibility of media on both the statistical acceleration and the turbulent diffusion of cosmic-ray particles is investigated. The averaging over an ensemble of random velocity fields of the medium was performed in the kinetic equation. The kinetic coefficients, which are responsible for the particle acceleration, were obtained in the cases of weak and strong scattering due inhomogeneous magnetic fields. 相似文献
455.
G. M. Petrov 《Astrophysics and Space Science》1991,177(1-2):269-270
The classical method of determination of the absolute azimuth (or Bessel's parameter n) can secure sufficiently precision for RA from observations of stars at high geographical latitudes during polar night only. 相似文献
456.
E. F. Arias C. Boucher M. Feissel J. -F. Lestrade 《Astrophysics and Space Science》1991,177(1-2):187-192
The relative orientations of various VLBI celestial reference frames are evaluated on the basis of coordinate differences of common sources. It is shown that an accuracy better than 0.001 can be achieved. Possible regional deformations in the different catalogues are investigated; they are found to reach a few 0.001 in some restricted zones. The application of these studies to the realisation of a combined celestial reference frame consistent with the BIH Terrestrial System is outlined. 相似文献
457.
Glenn M. Frye Jr. Philip P. Dunphy Edward L. Chupp Paul Evenson 《Solar physics》1988,118(1-2):321-346
458.
The surface distribution of M stars is studied by differentiating them according to whether they show a circumstellar dust shell (CS) or not. Analysis shows that galactic latitudinal and longitudinal distributions are not determined by spectral subclasses alone. The study also indicates that M-type stars with CS have higher luminosities in the K band than those without CS. The M stars used in the study are obtained from theTwo-Micron Sky-Survey Catalogue (IRC) which is a most unbiased sample with respect to the interstellar extinction. The CS feature is identified by the ratio of flux densities at 12 and 25 m in the IRAS point source catalog. 相似文献
459.
M. J. Hagyard 《Solar physics》1988,115(1):107-124
We have analyzed the vector magnetic field of an active region at a location of repeated flaring to determine the nature of the currents flowing in the areas where the flares initiated. The component of electric current density crossing the photosphere along the line-of-sight was derived from the observed transverse component of the magnetic field. The maximum concentrations of these currents occurred exactly at the sites of flare initiation and where the photospheric field was sheared the most. The calculated distribution of current density at the flare sites suggested that currents were flowing out of an area of positive magnetic polarity and across the magnetic inversion line into two areas of negative polarity. This interpretation was reinforced by a calculation of the source field, the magnetic field produced in the photosphere by the electric currents above the photosphere. In the vicinity of the flare sites, the calculated source field exhibited three particular characteristics: (1) maximum magnitudes at the sites of flare initiation, (2) a rotational direction where the vertical current density was concentrated, and (3) a fairly constant angular orientation with the magnetic inversion line. The source field was thus very similar to the field produced by two arcades of currents crossing the inversion line at the locations of greatest magnetic shear with orientations of about 60° to the inversion line. With this orientation, the inferred arcades would be aligned with the observed chromospheric fibrils seen in the H data so that the currents were field-aligned above the photosphere. The field thus exhibited a vertical gradient of magnetic shear with the shear decreasing upward from the photosphere. We estimated the currents in the two arcades by matching the source field derived from observations with that produced by a model of parallel loops of currents. We found that the loops of the model would each have a radius of 4500 km, a separation of 1830 km, and carry a current of 0.15 × 1012 A. Values of vertical current densities and source fields appearing in the umbrae of the two large sunspots away from the flare sites were shown to lie at or below the level of uncertainty in the data. The main source of this uncertainty lay in the method by which the 180° ambiguity in the azimuth of the transverse field is resolved in umbral areas. We thus concluded that these quantities in large umbrae should be treated with a healthy skepticism. Finally, we found that the source field at the flare sites was produced almost entirely by the angular difference between the observed and potential field and not by the difference in field intensity. 相似文献
460.
The transport of thermal radiation has been considered within a finite slab which absorb and scatter anisotropically. The problem involves the space-dependent single-scattering albedow(x). Two approximations are taken forw(x). In the first it is represented in exponential form asw(x)=w
0 exp(–x/s), wherew
0 ands are given constants andx is the optical variable. The second approximation assumes the formw(x) =
r=0
R
d
r
*
p
r
(x/a), whered
r
*
are known expansion coefficients anda is the half optical thickness of the slab. Analytic expressions for the forward, backward radiation intensities and fluxes are given in each approximation. The solution of the linear transport equation is performed on the basis of integral Fourier transforms. 相似文献