Scanning electron microscopy,cathodoluminescence, and Raman spectroscopy of experimentally shock‐metamorphosed quartzite     

Arnold Gucsik  Christian Koeberl  Franz Brandsttter  Eugen Libowitzky  Wolf Uwe Reimold 《Meteoritics & planetary science》2003,38(8):1187-1197

Abstract— We studied unshocked and experimentally (at 12, 25, and 28 GPa, with 25, 100, 450, and 750°C pre‐shock temperatures) shock‐metamorphosed Hospital Hill quartzite from South Africa using cathodoluminescence (CL) images and spectroscopy and Raman spectroscopy to document systematic pressure or temperature‐related effects that could be used in shock barometry. In general, CL images of all samples show CL‐bright luminescent patchy areas and bands in otherwise nonluminescent quartz, as well as CL‐dark irregular fractures. Fluid inclusions appear dominant in CL images of the 25 GPa sample shocked at 750°C and of the 28 GPa sample shocked at 450°C. Only the optical image of our 28 GPa sample shocked at 25°C exhibits distinct planar deformation features (PDFs). Cathodoluminescence spectra of unshocked and experimentally shocked samples show broad bands in the near‐ultraviolet range and the visible light range at all shock stages, indicating the presence of defect centers on, e.g., SiO₄ groups. No systematic change in the appearance of the CL images was obvious, but the CL spectra do show changes between the shock stages. The Raman spectra are characteristic for quartz in the unshocked and 12 GPa samples. In the 25 and 28 GPa samples, broad bands indicate the presence of glassy SiO₂, while high‐pressure polymorphs are not detected. Apparently, some of the CL and Raman spectral properties can be used in shock barometry.  相似文献   

Genesis of platinum-group minerals in the Las Aguilas mafic-ultramafic rocks, San Luis Province, Argentina: textural, chemical and mineralogical evidence     

A. Mogessie  Ch. A. Hauzenberger  G. Hoinkes  A. Felfernig  E. F. Stumpfl  E. A. Bjerg  J. Kostadinoff 《Mineralogy and Petrology》2000,68(1-3):85-114

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Die stratiforme Sulfidlagerstätte Walchen,Steiermark, Österreich: Geochemie und Genese     

J. Schlüter  M. Tarkian  E. F. Stumpfl 《Mineralogy and Petrology》1984,33(4):287-296

Zusammenfassung Die Neubearbeitung derstratiformen Sulfidlagerstätte Walchen bei Öblarn, Steiermark, offen-bart eine eisenbetonte submarin-exhalative Metallkonzentration in einem vulkano-sedimentären Rahmen. Dieser liegt heute in Form metamorpher Gesteine der untersten Grünschieferfazies vor. Mineralchemische Untersuchungen zeigen, daß die ehemalige intensivste metamorphe Überprägung der Lagerstätte im Bereich von 450°–500°C oberhalb 4 kb stattgefunden hat. Metavulkanite, vertreten durch Grünschiefer, lassen alkalibasaltische Affinität erkennen. Die vulkano-tektonische Position der Lagerstätte ist in einem intrakontinentalen Riftsystem zu sehen.

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The stratiform sulphide deposit at walchen, styria, austria: Geochemistry and genesis

Summary The Walchen deposit consists of a 1–2 m thick layer of massive to disseminated pyrite-pyrrhotite-chalcopyrite ore with an average grade of 1% Cu. It has been mined intermittently in the past. The ore horizon occurs within sericitic and quartzitic phyllites which carry intercalations with significant carbonate, garnet and graphite contents. The succession is of lower Paleozoic age and forms part of the Grauwackenzone, a volcano-sedimentary unit which separates the Central Alps from the Northern Calcareous Alps.The precursor rocks of the ore environment have been pelites and sandstones; greenschists occur in the hanging wall of the mineralization. Major and trace element analyses of greenschists reveal them as low-grade metamorphic equivalents of continental alkali basalts. Hydrothermal systems generated by volcanic activity were responsible for deposition of stratiform sulphides. The predominance of clastic sediments and the absence of stringer zones point towards a shallow depositional basin.Microprobe analyses of garnets from the ore environment reveal an increase in spessartine contents from 7 mol% in phyllites to 20 mol% in the vicinity of the ore horizon. Similar data have been reported from other stratabound base metal deposits (Broken Hill, N.S.W.; Kreuzeck Mountains, Austria; Gamsberg, South Africa); the manganese concentrations represent fossil manganese haloes.Pyrite carries minor Ni and Co (up to 0.03, respectively 0.3%), pyrrhotite averages 0.8% Ni and 0.1% Co, Fe-contents of sphalerite vary from 6.41–9.33%; Cd, In and Mn have not been recorded.Garnet-biotite pairs suggest maximum metamorphic temperatures of 450°–500°C: pressures of 4 to 5 kb have been estimated. The Walchen deposit is interpreted as the product of submarine exhalative processes in an incipient rift. It was affected by prograde metamorphism during the Variscan orogeny, and by retrograde affects during a later event. Isochemical metamorphism resulted in the preservation of a primary manganese halo.

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Mit 6 Abbildungen  相似文献   

Sulfide and platinum mineralization in the Merensky Reef: evidence from hydrous silicates and fluid inclusions   总被引：5，自引：1，他引：5  

Christian G. Ballhaus  Eugen F. Stumpfl 《Contributions to Mineralogy and Petrology》1986,94(2):193-204

The base metal sulfides of the Merensky Reef are associated with hydrous silicates and intense deuteric hydrous alteration of cumulus and postcumulus silicates. Biotite and phlogopite crystallized in the vicinity of sulfides from a volatile-enriched highly fractionated intercumulus melt. Amphibole, chlorite, and talc are later alteration phases of cumulus pyroxene and intercumulus plagioclase. Biotite is often accompanied by zircon, rutile, and quartz. Accessory quartz hosts a complex suite of H₂O-NaCl-(CaCl₂)-CO₂-CH₄ fluid inclusions which have thus far not been described from the Merensky Reef. The earliest fluid inclusion compositions are NaCl-(H₂O) with less than 10 vol.% water; CO₂ coexisting with a halite daughter crystal and brine; and polyphase inclusions with up to six daughter and accidental phases and high contents of divalent cations. The maximum trapping temperature is around 730° C at 4 to 5 kb pressure. Later inclusion generations are H₂O-NaCl, CO₂-H₂O, and pure CO₂ and CH₄. The presence of Cl-rich fluids during the intercumulus stage of the crystallizing Merensky Reef is directly related to the mode of sulfide precipitation. Prior to sulfide unmixing in a hydrous magma sulfur is likely to be present as H₂S. Sulfur saturation causes reaction of H₂S with oxides of the silicate melt to form a sulfide melt plus water. During reaction the magma is enriched in water until a separate fluid unmixes. It carries all compounds with high fluid/melt partition coefficients, as well as metals capable of forming OH- and Cl-complexes. Precious metals are assumed to have fractionated into the Cl-rich fluid as Cl-complexes rather than being dissolved in the sulfide melt. During the cooling evolution of the fluid the precious elements precipitate around the periphery of sulfide melt droplets. The model proposed explains the distribution pattern of platinum-group minerals in the Merensky Reef better than any orthomagmatic mineralization concept offered so far.  相似文献   

Book reviews     

Klemm  D. D.  Stumpfl  E. F.  Saupé  F. 《Mineralium Deposita》1983,18(1):131-133

Mineralium Deposita -  相似文献   

Anmerkungen zu „Geochemische Untersuchungen an Sedimenten des Persischen Golfs“     

Martin Hartmann  Heinz Lange  Eugen Seibold 《Contributions to Mineralogy and Petrology》1971,31(2):159-163

Ohne Zusammenfassung  相似文献   

Biologische Untersuchung der Limmat zwischen Zürichsee und Wettingen, 1974 bis 1980     

Prof.Dr. Eugen A. Thomas  Dr. Ferdinand Schanz 《Aquatic Sciences - Research Across Boundaries》1981,43(2):296-339

Biological investigations of that part of the River Limmat lying between Quaibrücke and Wettingen were carried out from 1974 to 1980. An influence of the waste water from the Werdhölzli sewage treatment plant on the plant and animal communities of the river bed was evident. This influence was especially plain to be seen immediately below the point of introduction of the waste water. The incidence of pollution indicators decreased downriver from this point. Biotests, using periphyton from stones taken from the shore of the Zürichsee, yielded harvests which were clearly higher in Limmat water taken from points downstream from the sewage works than in water taken from points upstream.  相似文献   

Book review     

E. F. Stumpfl 《Mineralogy and Petrology》1987,36(3-4):267-268

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Buchbesprechungen     

G. Kurat  E. F. Stumpfl 《Mineralogy and Petrology》1977,24(4):299-302

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Tektonik und Dimensionalanalyse     

Eugen Wegmann 《International Journal of Earth Sciences》1948,36(1):83-84

Ohne Zusammenfassung  相似文献