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  • 1
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Science Inc
    Journal of metamorphic geology 21 (2003), S. 0 
    ISSN: 1525-1314
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Geologie und Paläontologie
    Notizen: The upper deck of the East Athabasca mylonite triangle (EAmt), northern Saskatchewan, Canada, contains mafic granulites that have undergone high P–T metamorphism at conditions ranging from 1.3 to 1.9 GPa, 890–960 °C. Coronitic textures in these mafic granulites indicate a near-isothermal decompression path to 0.9 GPa, 800 °C. The Godfrey granite occurs to the north adjacent to the upper deck high P–T domain. Well-preserved corona textures in the Godfrey granite constrain igneous crystallization and early metamorphism in the intermediate-pressure granulite field (Opx + Pl) at 1.0 GPa, 775 °C followed by metamorphism in the high pressure granulite field (Grt + Cpx + Pl) at 1.2 GPa, 860 °C. U–Pb geochronology of zircon in upper deck mafic granulite yields evidence for events at both c. 2.5 Ga and c. 1.9 Ga. The oldest zircon dates are interpreted to constrain a minimum age for crystallization or early metamorphism of the protolith. A population of 1.9 Ga zircon in one mafic granulite is interpreted to constrain the timing of high P–T metamorphism. Titanite from the mafic granulites yields dates ranging from 1900 to 1894 Ma, and is interpreted to have grown along the decompression path, but still above its closure temperature, indicating cooling following the high P–T metamorphism from c. 960–650 °C in 4–10 Myr. Zircon dates from the Godfrey granite indicate a minimum crystallization age of 2.61 Ga, without any evidence for 1.9 Ga overgrowths. The data indicate that an early granulite facies event occurred at c. 2.55–2.52 Ga in the lower crust (c. 1.0 GPa), but at 1.9 Ga the upper deck underwent high P–T metamorphism, then decompressed to 0.9–1.0 GPa. Juxtaposition of the upper deck and Godfrey granite would have occurred after or been related to this decompression. In this model, the high P–T rocks are exhumed quickly following the high pressure metamorphism. This type of metamorphism is typically associated with collisional orogenesis, which has important implications for the Snowbird tectonic zone as a fundamental boundary in the Canadian Shield.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Science Inc
    Journal of metamorphic geology 23 (2005), S. 0 
    ISSN: 1525-1314
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Geologie und Paläontologie
    Notizen: A new quantitative approach to constraining mineral equilibria in sapphirine-bearing ultrahigh-temperature (UHT) granulites through the use of pseudosections and compatibility diagrams is presented, using a recently published thermodynamic model for sapphirine. The approach is illustrated with an example from an UHT locality in the Anápolis–Itauçu Complex, central Brazil, where modelling of mineral equilibria indicates peak metamorphic conditions of about 9 kbar and 1000 °C. The early formed, coarse-grained assemblage is garnet–orthopyroxene–sillimanite–quartz, which was subsequently modified following peak conditions. The retrograde pressure–temperature (P–T) path of this locality involves decompression across the FeO–MgO–Al2O3–SiO2 (FMAS) univariant reaction orthopyroxene + sillimanite = garnet + sapphirine + quartz, resulting in the growth of sapphirine–quartz, followed by cooling and recrossing of this reaction. The resulting microstructures are modelled using compatibility diagrams, and pseudosections calculated for specific grain boundaries considered as chemical domains. The sequence of microstructures preserved in the rocks constrains a two-stage isothermal decompression–isobaric cooling path. The stability of cordierite along the retrograde path is examined using a domainal approach and pseudosections for orthopyroxene–quartz and garnet–quartz grain boundaries. This analysis indicates that the presence or absence of cordierite may be explained by local variation in aH2O. This study has important implications for thermobarometric studies of UHT granulites, mainly through showing that traditional FMAS petrogenetic grids based on experiments alone may overestimate P–T conditions. Such grids are effectively constant aH2O sections in FMAS-H2O (FMASH), for which the corresponding aH2O is commonly higher than that experienced by UHT granulites. A corollary of this dependence of mineral equilibria on aH2O is that local variations in aH2O may explain the formation of cordierite without significant changes in P–T conditions, particularly without marked decompression.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    [s.l.] : Nature Publishing Group
    Nature 246 (1973), S. 203-205 
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] Visually, 1548 + 115 =4Cl 1.50 (ref. 4) is another close pair of blue stellar objects. The brighter object (1548 + 115a) is approximately 17 mag, and is followed 4.8 arc s east and 0.4 arc s south by the 19 mag object 1548 + 115b. The pair was first noted by Hazard and Jauncey (see ref. 5) in a ...
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    [s.l.] : Nature Publishing Group
    Nature 243 (1973), S. 336-337 
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] A finding chart for OQ172 is given by Veron4, who notes that it is a "blue stellar object". From our inspection of the Palomar Sky Survey plates we agree with Veron's assessment of the colour of OQ172, although Gent et al3 list it as stellar, that is an object with neutral colours. Radio fluxes for ...
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    [s.l.] : Nature Publishing Group
    Nature 246 (1973), S. 205-208 
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] To avoid any assumptions as to the nature of the red-shifts, two of us (D. J. and*C. H.) started, not with a list of QSOs, but with a list of 280 radio sources selected from the 4C catalogue and for which we had measured improved positions. The fields around each of these sources were examined ...
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    [s.l.] : Nature Publishing Group
    Nature 273 (1978), S. 374-375 
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] The club-heads are obtained from within the large mounds which birds of the family Megapodiidae construct in the local forests to incubate their eggs. The fungal material (called utiyani) is dried and then carved into either a smoothly rounded (Fig. 1) or a toothed disk always with a central hole ...
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Social psychiatry and psychiatric epidemiology 2 (1967), S. 158-167 
    ISSN: 1433-9285
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé Les buts et les avantages des registres de cas psychiatriques sont résumés. Quelques résultats préliminaires de trois de ces registres, celui d'Aberdeen (Ecosse), de Baltimore (USA) et de Camberwell (Londres, Angleterre) sont comparés. On y note une fréquence journalière d'environ 1% de la population âgée de plus de 15 ans dans les trois zones, un autre l% étant noté pendant les 12 mois consécutifs. Certaines différences dans la distribution des âges et des sexes, dans la composition du diagnostic et dans la coordination entre agences et services sont discutées. Dans l'ensemble cependant, dans ces trois zones urbaines, les similitudes dépassent les différences. Des possibilités de futures comparaisons sont suggérées.
    Kurzfassung: Zusammenfassung Ziele und Vorteile eines psychiatrischen Fall-Registers werden zusammenfassend dargestellt. Es erfolgt ein Vergleich einiger vorläufiger Ergebnisse aus drei Registern, welche in Aberdeen (Schottland), Baltimore (USA) und Camberwell (London, England) gewonnen wurden. Die Stichtag-Häufigkeit bezogen auf eine Bevölkerung von über 15 Jahren in diesen drei Gebieten lag bei 1%; während der nachfolgenden 12 Monate kam ein weiterer Anteil von 1% der Bevölkerung hinzu. Diskutiert werden gewisse Unterschiede der Alters- und Geschlechtsverteilung, der diagnostischen Zusammensetzung und der Koordination zwischen verschiedenartigen psychiatrischen Einrichtungen. Aufs ganze gesehen überwogen in diesen drei Stadtgebieten die Ähnlichkeiten der Register-Resultate die Unterschiede. Abschließend werden die Aussichten künftiger Vergleiche erörtert.
    Notizen: Summary The aims and advantages of Psychiatric Case Registers are summarised. Some preliminary results from three such Registers, covering Aberdeen (Scotland), Baltimore (USA) and Camberwell (London, England) are compared. The reported prevalence on one day was about 1% of the population aged over 15 years in all three areas with another 1% being reported during the subsequent 12 months. Certain differences in age- and sex-distribution, in diagnostic composition, and in coordination between agencies and services are discussed. On the whole, however, in these three urban areas, the similarities outweigh the differences. Possibilities for future comparisons are suggested.
    Materialart: Digitale Medien
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