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171.
The design of the Data Management Facility (DMF), the system to handle the data from HST, has been based on the concepts of modularity and flexibility, so that changes inevitably due to occur during the long lifetime of the project could be gracefully accomodated. At the Space Telescope European Coordinating Facility (ST-ECF), new constraints have led the archive group to evolve the system, so to allow a more efficient ingesting of the data imported from the Space Telescope Science Institute (STScI), an easier browsing of the HST catalogue of observations, and a more efficient servicing of archive researchers' retrieval requests. In this paper, the European Science Data Archive of HST data is described, with particular reference to dataflow, hardware and software system structure, operations, differences with DMF, and foreseen developments.Affiliated with the Astrophysics Division, Space Science Dept., ESAThe observations of the NASA/ESA Hubble Space Telescope are obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555. 相似文献
172.
Gertrude?FriedlEmail author Fritz?Finger Jean-Louis?Paquette Albrecht?von?Quadt Neal?J.?McNaughton Ian?R.?Fletcher 《International Journal of Earth Sciences》2004,93(5):802-823
In an attempt to elucidate the pre-Variscan evolution history of the various geological units in the Austrian part of the Bohemian Massif, we have analysed zircons from 12 rocks (mainly orthogneisses) by means of SHRIMP, conventional multi-grain and single-grain U–Pb isotope-dilution/mass-spectrometry. Two of the orthogneisses studied represent Cadomian metagranitoids that formed at ca. 610 Ma (Spitz gneiss) and ca. 580 Ma (Bittesch gneiss). A metagranite from the Thaya batholith also gave a Cadomian zircon age (567±5 Ma). Traces of Neoproterozoic zircon growth were also identified in several other samples, underlining the great importance of the Cadomian orogeny for the evolution of crust in the southern Bohemian Massif. However, important magmatic events also occurred in the Early Palaeozoic. A sample of the Gföhl gneiss was recognised as a 488±6 Ma-old granite. A tonalite gneiss from the realm of the South Bohemian batholith was dated at 456±3 Ma, and zircon cores in a Moldanubian metagranitic granulite gave similar ages of 440–450 Ma. This Ordovician phase of magmatism in the Moldanubian unit is tentatively interpreted as related to the rifting and drift of South Armorica from the African Gondwana margin. The oldest inherited zircons, in a migmatite from the South Bohemian batholith, yielded an age of ca. 2.6 Ga, and many zircon cores in both Moravian and Moldanubian meta-granitoid rocks gave ages around 2.0 Ga. However, rocks from the Moldanubian unit show a striking lack of zircon ages between 1.8 and 1.0 Ga, reflecting an ancestry from Armorica and the North African part of Gondwana, respectively, whereas the Moravian Bittesch gneiss contains many inherited zircons with Mesoproterozoic and Early Palaeoproterozoic ages of ca. 1.2, 1.5 and 1.65–1.8 Ga, indicating a derivation from the South American part of Gondwana. 相似文献
173.
O. Eugster Ch. Thalmann A. Albrecht G. F. Herzog J. S. Delaney J. Klein R. Middleton 《Meteoritics & planetary science》1996,31(2):299-304
Abstract— Glass-rich separates were prepared from a sample of the basaltic lunar meteorite EET87521 rich in dark glass. Noble gas isotopic abundances and 26Al and 10Be activities were measured to find out whether shock effects associated with lunar launch helped to assemble these phases. Similar 10Be and 26Al activities indicate that all materials in EET87521 had a common exposure history in the last few million years before launch. However, the glass contains much higher concentrations of trapped gases and records a much longer cosmic-ray exposure, 100 Ma–150 Ma, in the lunar regolith than does the bulk sample. The different histories show that the glass existed long before the ejection of EET87521. The trapped 40Ar/36Ar ratio of 1.6 ± 0.1 implies that the lunar exposure that produced most of the stable cosmogenic noble gases began 500 Ma ago. Cosmogenic and trapped noble gas components correlate strongly in various temperature-release fractions and phases of EET87521, which is probably because the glass contains most of the gas. The trapped solar ratios, 20Ne/22Ne = 12.68 ± 0.20 and 36Ar/38Ar = 5.24 ± 0.05 can be understood as resulting from a mixture consisting of ~60% solar wind and 40% solar energetic particles (SEP). All EET87521 phases show a 40K-40Ar gas retention age of ~3300 Ma, which is in the range of typical lunar mare basalts. 相似文献
174.
175.
Natalia?StammEmail authorView authors OrcID profile Max?W.?Schmidt Dawid?Szymanowski Albrecht?von?Quadt Thabang?Mohapi Andre?Fourie 《Contributions to Mineralogy and Petrology》2018,173(9):76
The Let?eng-la-Terae kimberlite (Lesotho), famous for its large high-value diamonds, has five distinct phases that are mined in a Main and a Satellite pipe. These diatreme phases are heavily altered but parts of a directly adjacent kimberlite blow are exceptionally fresh. The blow groundmass consists of preserved primary olivine with Fo86?88, chromite, magnesio-ulvöspinel and magnetite, perovskite, monticellite, occasional Sr-rich carbonate, phlogopite, apatite, calcite and serpentine. The bulk composition of the groundmass, extracted by micro-drilling, yields 24–26 wt% SiO2, 20–21 wt% MgO, 16–19 wt% CaO and 1.9–2.1 wt% K2O, the latter being retained in phlogopite. Without a proper mineral host, groundmass Na2O is only 0.09–0.16 wt%. However, Na-rich K-richterite observed in orthopyroxene coronae allows to reconstruct a parent melt Na2O content of 3.5–5 wt%, an amount similar to that of highly undersaturated primitive ocean island basanites. The groundmass contains 10–12 wt% CO2, H2O is estimated to 4–5 wt%, but volatiles and alkalis were considerably reduced by degassing. Mg# of 77.9 and 530 ppm Ni are in equilibrium with olivine phenocrysts, characterize the parent melt and are not due to olivine fractionation. 87Sr/86Sr(i)?=?0.703602–0.703656, 143Nd/144Nd(i)?=?0.512660 and 176Hf/177Hf(i)?=?0.282677–0.282679 indicate that the Let?eng kimberlite originates from the convective upper mantle. U–Pb dating of groundmass perovskite reveals an emplacement age of 85.5?±?0.3 (2σ) Ma, which is significantly younger than previously proposed for the Let?eng kimberlite. 相似文献
176.
Parampreet Kaur Naveen Chaudhri Albrecht W. Hofmann Ingrid Raczek Martin Okrusch Susanne Skora Jürgen Koepke 《International Journal of Earth Sciences》2014,103(4):1083-1112
The late Palaeoproterozoic (1.72–1.70 Ga) ferroan granites of the Khetri complex, northern Aravalli orogen, NW India, were extensively metasomatised ~900 Ma after their emplacement, at around 850–830 Ma by low-temperature (ca. 400 °C) meteoric fluids that attained metamorphic character after exchanging oxygen with the surrounding metamorphic rocks. Albitisation is the dominant metasomatic process that was accompanied by Mg and Ca metasomatism. A two-stage metasomatic model is applicable to all the altered ferroan intrusives. The stage I is represented by a metasomatic reaction interface that developed as a result of transformation of the original microcline–oligoclase (An12–14) granite to microcline–albite (An1–3) granite, and this stage is rarely preserved. In contrast, the stage II metasomatic reaction front, where the microcline-bearing albite granite has been transformed to microcline-free albite granite, is readily recognisable in the field and present in most of the intrusives. Some of them lack an obvious reaction interface due to the presence of stage II albite granites only. When studied in isolation, these intrusives were incorrectly classified and their tectonic setting was misinterpreted. Furthermore, our results show that the mafic mineralogy of metasomatised granites has a significant impact on the characterisation of such rocks in the magmatic classification and discrimination diagrams. Nevertheless, the stage I metasomatised granites can be appropriately characterised in these diagrams, whereas the characterisation of the stage II granites will lead to erroneous interpretations. The close spatial association of these high heat producing ferroan granites with iron oxide–copper–gold (IOCG), U and REE mineralisation in the region indicates a genetic link between the metasomatism and the mineralisation. World-class IOCG, U and REE deposits are associated with metasomatised ferroan granites, suggesting that such a relationship may act as a critical first-order exploration target for undiscovered mineral deposits. 相似文献
177.
The Preparation and Preliminary Characterisation of Eight Geological MPI-DING Reference Glasses for In-Situ Microanalysis 总被引:13,自引:4,他引:9
Klaus Peter Jochum Donald B. Dingwell Alexander Rocholl Brigitte Stoll Albrecht W. Hofmann S. Becker A. Besmehn D. Bessette H.-J. Dietze P. Dulski J. Erzinger E. Hellebrand P. Hoppe I. Horn K. Janssens G.A. Jenner M. Klein W.F. McDonough M. Maetz K. Mezger C. Müker I.K. Nikogosian C. Pickhardt I. Raczek D. Rhede H.M. Seufert S.G. Simakin A.V. Sobolev B. Spettel S. Straub L. Vincze A. Wallianos G. Weckwerth S. Weyer D. Wolf M. Zimmer 《Geostandards and Geoanalytical Research》2000,24(1):87-133
Eight silicate glasses were prepared by directly fusing and stirring 50-100 g each of basalt, andesite, komatiite, peridotite, rhyolite, and quartz-diorite. These are referred to as MPI-DING glasses and were made for the purpose of providing reference materials for geochemical, in-situ microanalytical work. Results from various analytical techniques indicate that individual glass fragments are well homogenised with respect to major and trace elements at the μm to mm scale. Heterogeneities due to quench crystallisation of olivine have been observed in small and limited areas of the two komatiitic glasses. In order to obtain concentration values for as many elements as possible, the glasses were analysed by a variety of bulk and microanalytical methods in a number of laboratories. The analytical uncertainties of most elements are estimated to be between 1% and 10%. From the analytical data, preliminary reference values for more than sixty elements were calculated. The analytical uncertainties of most elements are estimated to be between 1% and 10%. 相似文献
178.