Subsolidus orthopyroxene-clinopyroxene systematics in the system CaO-MgO-SiO2 to 60 kb: a re-evaluation of the regular solution model     

Klaus G. Nickel  Gerhard Brey 《Contributions to Mineralogy and Petrology》1984,87(1):35-42

On the basis of an increased set of experimental data, covering the miscibility gap between orthopyroxene and clinopyroxene from 2 to 60 kb with a temperature range of 850–1,500° C, we present a new version of a regular solution model. The model with two independent regular solutions for opx and cpx is capable of reproducing experimental data in the system CaO-MgO-SiO₂ over a large range of temperatures and pressures. It is qualitatively in agreement with observed stability regions for an Fe-free low-Ca pyroxene, termed pigeonite. The model is constrained by and thus consistent with calorimetric measurements on pyroxenes. The simple form of equations provides a good starting point for the development of more reliable thermometers based on the miscibility gap.Abbrevations Used in the Text cpx clinopyroxene - di diopside, CaMgSi₂O₆ - en enstatite, Mg₂Si₂O₆ - pig pigeonite - opx orthopyroxene - H (i) molar enthalpy difference (of reaction i) - S (i) molar entropy difference of reaction (i) - V (i) molar volume difference of reaction (i) - X[i]j mole fraction of i in phase j  相似文献   

Die entwicklung der Landwirtschaft in den bantugebieien von Süd- und Südwestafrika: Magura,W. (1970): Afrika-Forschungsbericht Nr. 26, Afrika-Studienstelle des IFO-lnstituts. 211 S., 4 Karten. München: Weltforum Verlag. DM 20,-     

Erwin Mai 《Geoforum》1974,5(3):92-93

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Interaction of organic compounds with calcium carbonate-II. Organo-carbonate association in Recent sediments     

Erwin Suess 《Geochimica et cosmochimica acta》1973,37(11):2435-2447

Surface area measurements as well as organic carbon, nitrogen and phosphorus analyses on various grain size fractions of carbonate mud samples confirm that in natural environments of carbonate deposition, surface sorption processes take place which are similar to those described earlier for dissolved organics and artificially suspended calcite particles in both seawater and synthetic solutions.The specific surface area of the sediment increases from 1.8m²/g for the coarse-grained fraction to 12.5 m²/g for the fine material; likewise organic carbon, nitrogen and phosphorus increase with increasing surface area so that there are 1.20 mg C, 0.175 mg N and 0.06–0.20 mg P associated with every square meter of carbonate surface irrespective of the mineralogy of the sediment particles.It appears that the organic matter in these sediments is similar in composition, structure and quantity to the organic layers produced in sorption experiments. With their apparently defined structure and ubiquitous nature, these layers could determine the mineralogy and orientation of submarine carbonate cement or could even be a prerequisite to calcification in general.  相似文献   

Codification of Unnamed Minerals     

Smith  Dorian G. W.; Nickel  Ernest H. 《Journal of Petrology》2008,49(3):581-583

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The metamorphic evolution of migmatites from the Ötztal Complex (Tyrol,Austria) and constraints on the timing of the pre-Variscan high-T event in the Eastern Alps     

Werner F. Thöny  Peter Tropper  Friederike Schennach  Erwin Krenn  Friedrich Finger  Reinhard Kaindl  Franz Bernhard  Georg Hoinkes 《Swiss Journal of Geoscience》2008,101(1):111-126

Within the Ötztal Complex (ÖC), migmatites are the only geological evidence of the pre-Variscan metamorphic evolution, which led to the occurrence of partial anatexis in different areas of the complex. We investigated migmatites from three localities in the ÖC, the Winnebach migmatite in the central part and the Verpeil- and Nauderer Gaisloch migmatite in the western part. We determined metamorphic stages using textural relations and electron microprobe analyses. Furthermore, chemical microprobe ages of monazites were obtained in order to associate the inferred stages of mineral growth to metamorphic events. All three migmatites show evidence for a polymetamorphic evolution (pre-Variscan, Variscan) and only the Winnebach migmatite shows evidence for a P-accentuated Eo-Alpine metamorphic overprint in the central ÖC. The P-T data range from 670–750 °C and < 2.8 kbar for the pre-Variscan event, 550–650 °C and 4–7 kbar for the Variscan event and 430–490 °C and ca. 8.5 kbar for the P-accentuated Eo-Alpine metamorphic overprint. U-Th-Pb electron microprobe dating of monazites from the leucosomes from all three migmatites provides an average age of 441 ± 18 Ma, thus indicating a pervasive Ordovician-Silurian metamorphic event in the ÖC.  相似文献   

A field trial for in-situ bioremediation of 1,2-DCA   总被引：2，自引：0，他引：2  

Mark Dyer  Erwin van Heiningen  Jan Gerritse 《Engineering Geology》2003,70(3-4):315-320

Historic spillages of chlorinated hydrocarbons at a vinyl chloride plant in the Rotterdam Botlek area in The Netherlands have lead to contamination of the underlying aquifer. The principal contaminant is 1,2-dichloroethane (1,2-DCA). The contamination is temporarily contained by a pump-and-treat system. A field trial was carried out to investigate the feasibility of treating the dissolved phase of 1,2-DCA via reductive dechlorination by injection of an aqueous solution of methanol, ammonium chloride and sodium chloride into the confined aquifer using an array of eight boreholes. Biodegradation of 1,2-DCA was localised. This was attributed to limited mixing of the carbon substrate within the test zone. In addition, clogging of recharge wells complicated groundwater circulation.  相似文献   

Die Mikroseismik und ihre Anwendung zum Abschätzen der Dicke der Kontinentalschollen     

Dozent Dr. Erwin Hardtwig 《Pure and Applied Geophysics》1949,14(3-4):203-224

Zusammenfassung An Hand einiger Wetterlagen mit besonders starker Mikroseismik wird der Verlauf von Amplituden und Perioden in Stuttgart verfolgt. Das Gesetz der Abhängigkeit zwischen Periode und Amplitude wird empirisch ermittelt, das Periodenspektrum gezeichnet. Die am häufigsten auftretende Periode wird zur Berechnung der Dicke der schwingenden Schicht benutzt unter der Annahme, dass diese Schicht mit ihrer Unterlage lose verbunden ist und die Art der Schwingungen sich nicht wesentlich von Rayleighwellen unterscheidet. Es ergibt sich so der theore tische Zusammenhang zwischen Periode und Amplitude einerseits und der Schichtdicke andrerseits. Sie beträgt für Norwegen etwas über 40 km.

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Summary With the help of several weather-situations with particularty violent microseism the progress of amplitudes and periods as perceived at Stuttgart is examinated. The law of dependency between period and amplitude is found empirically, the spectrum of periods is drawn up. The period, which occurs most frequently is used for calculating the thickness of the swinging layer as this layer is supposed to be in loose connection with its support and as the sort of oscillations is not essentially different from Rayleight waves. Thus there is found the theoretical connection between periods and amplitudes and, on the other side, the thickness of layer of something more than 40 km for Norway.

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Bemerkungen zur Zwillingsbildung bei Plagioklasen     

Dr. Erwin Nickel 《Contributions to Mineralogy and Petrology》1949,2(1-2):176-188

Ohne Zusammenfassung  相似文献   

Beiträge,zur Petrographie des Odenwaldes. IV. Wechselbeziehungen zw1schen Dioriten,Graniten und Schiefern im westlichen Odenwald     

Edwin Nickel 《Contributions to Mineralogy and Petrology》1948,1(4):427-470

Ohne Zusammenfassung  相似文献   

Apparative Bemerkungen zu Messungen nach dem Drehtisehprinzip     

Dr. E. Nickel  G. Frenzel 《Contributions to Mineralogy and Petrology》1951,2(6):552-555

Ohne Zusammenfassung  相似文献