The transition from pyroxene granulite facies to garnet clinopyroxene granulite facies. Experiments in the system CaO-MgO-Al2O3-SiO2     

Birger Hansen 《Contributions to Mineralogy and Petrology》1981,76(2):234-242

The pressure-temperature curve for the equilibrium anorthite+2enstatite=pyrope+diopside+quartz has been determined in the system CaO-MgO-Al₂O₂-SiO₂ to be between 13.4 and 14.0 kbars at 900° C. The slope up to 1,240° C is 8.5 bar/K. The entropy change at 1,200 K is 20 kJ. These data, combined with data from the literature, lead to a geobarometer equation which, when applied to rocks from the Agto area (West Greenland), gives pressure estimates of 6–10 kbars at 800° C. The results are consistent for rocks of differing Fe/Mg ratios and are consistent with independent pressure estimates.  相似文献   

A three dimensional Prandtl layer conception for air currents over moving rough water surfaces     

Prof. Dr. Hans Peter Schmitz 《Ocean Dynamics》1983,36(4):129-144

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Survival,duration of larval stages,and size of postlarvae of grass shrimp,Palaemonetes pugio,reared from kepone® contaminated and uncontaminated populations in Chesapeake Bay     

Anthony J. Provenzano  Kathleen B. Schmitz  Mark A. Boston 《Estuaries and Coasts》1978,1(4):239-244

Replicate groups of larvae from each of three female grass shrimp,Palaemonetes pugio, collected at each of six sites within Chesapeake Bay were reared in the laboratory to metamorphosis at 25°C, 25 ppt salinity. They were provided with approximately 300Artemia nauplii/larva/day. Sites were selected to provide both suspected Kepone^® contaminated and non-contamined shrimp populations. A sample of eggs, adult females with and without eggs, and newly hatched larvae from each site were analyzed by Virginia Institute of Marine Science for Kepone as were postlarvae obtained through laboratory rearings. Females and eggs from the James River had highest concentrations of Kepone (0.63 and 0.47 ppm, respectively) with samples from the Lafayette River at the mouth of the James River having the second highest levels (0.04 and 0.4 ppm). Concentrations in ovigerous females and eggs in the populations most distant from the James (mouth of Potomac and upper Potomac River) were at or below the limits of detectability (0.001 to 0.015 ppm). In laboratory reared postlarvae from each site, concentrations of Kepone were undetectable. Despite these apparent differences in Kepone concentrations in the various populations we found no significant differences in larval survival, larval duration, or length of post-larvae attributable to site of origin. Highly significant differences in larval duration and size of post-larvae were attributable to parental variation.  相似文献   

Kritische Betrachtungen zu gebräuchlichen Methoden der Ermittlung des Windschubs auf dem Meere     

Hans Peter Schmitz 《Ocean Dynamics》1961,14(5):169-193

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Existenzbedingungen für stationäre und beschleunigungsfreie Strömungsfelder auf der rotierenden Erde,insbesondere am Äquator     

Hans Peter Schmitz 《Ocean Dynamics》1961,14(4):135-152

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Eine numerische Approximation der monsunerzeugten Zirkulationen im Arabischen Meer     

H. P. Schmitz 《Ocean Dynamics》1967,20(5):205-217

Zusammenfassung In Anwendung eines einfachen numerischen Zweischichtenmodells auf den Nordteil des Arabischen Meeres wurden Massentransporte, Oberflächen- und Sprungschichtlage unter Vorgabe monsunaler Wind- und Luftdruckverteilungen berechnet. Das Modell basiert auf den vertikal integrierten Kontinuitäts- und Bewegungsgleichungen. Für beide Monsune ergeben sich Massentransportrichtungen und Sprungschichtlageänderungen in qualitativer Übereinstimmung mit den Beobachtungen:Im Falle des SW-Monsuns resultiert eine beachtliche Anhebung der Sprungschicht nicht nur vor der arabischen Küste, sondern in geringerem Maße auch vor der indischen Küste im Bereich starker südöstlicher Oberflächenströmung. — Das Modell für den NE-Monsun enthält den südwestlichen Ausstrom der Oberschicht vor der arabischen Küste ebenso wie den südöstlichen Ausstrom vor der indischen Küste.

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A numerical approximation of the monsoon-generated circulation in the Arabian Sea

Summary By applying a simple two-layered numerical model to the northern part of the Arabian Sea, the mass transports and the elevations of the sea level and the pycnocline have been computed from prescribed monsoonal wind and air pressure distributions. The model is based on the vertically integrated (primitive) equations of motion and continuity; it starts with the ocean at rest. For both the monsoons it gives the mass transports and the elevations in qualitative agreement with known observations:In the case of SW-monsoon we get a considerable elevation of the pycnocline not only in front of the Arabian shore but also a slightly smaller one within the branch of the relatively strong south-eastern surface current that develops near the Indian coast.—The model of the NE-monsoon contains the south-westerly outflow of the surface layer in front of the Arabian coast as well as its south-easterly outflow in front of the Indian coast.

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Une approximation numérique des circulations dues aux moussons dans la mer d'Arabie

Résumé Au moyen d'un simple modèle numérique à deux couches sur la partie Nord de la mer d'Arabie, on a calculé les transports de masses, et les positions des couches superficielles et de transition à partir des distributions de pression atmosphérique et de vent de mousson. Le modèle s'appuie sur l'intégration verticale des équations de continuité et de mouvement. Pour les deux moussons il résulte que les directions des transports de masse et les modifications de position de la couche de transition sont en concordance qualitative avec les observations:Dans le cas de la mousson de SW on trouve une remontée sensible de la couche de transition non seulement devant la côte arabe, mais aussi, dans une moindre mesure, devant la côte indienne dans la zone de fort courant de surface portant au SE. — Le modèle pour la mousson de NE contient le flux de sortie SW de la couche superficielle devant la côte arabe ainsi que le flux de sortie SE devant la côte indienne.

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The Lyngen Gabbro: the lower crust of an Ordovician Incipient Arc     

Astri?J.?S.?KvassnesEmail author  Anita?Hetland?Strand  Heidi?Moen-Eikeland  Rolf?Birger?Pedersen 《Contributions to Mineralogy and Petrology》2004,148(3):358-379

We present evidence for the origin of the Lyngen Gabbro of the Ordovician Lyngen Magmatic Complex in Troms, Northern Norway. The two magmatic suites of the Lyngen Gabbro strike parallel NNE-SSW, and have distinct magmatic signatures. We define these signatures by using major and trace-element analyses together with selected major- and trace-element mineral analyses and ¹⁴³Nd/¹⁴⁴Nd-isotope whole-rock analyses of gabbroic to tonalitic plutonic rocks from seven detailed cross-sections from this large gabbro-complex. The Western suite of the Lyngen Gabbro precipitated from magma that may have been derived from the same system as the associated volcanic rocks. The gabbros have high An-content (An_>90) of their plagioclases relative to co-existing mafic minerals. Together with somewhat high _Nd(t) values (+6), this implies that the parental magmas were hydrous tholeiites similar to those found in back arc basins today. The Eastern suite, on the other hand, consist of cumulates that were precipitated from melts resembling those of ultra-depleted high-Ca boninitic magmas found in fore-arcs. Extremely high-An plagioclases (An_>95) co-exist with evolved mafic minerals and oxides, and the _Nd(t) values are lower (+4) than in the Western suite. The Eastern suite has no volcanic counterpart, but dikes intersecting the suites have compositions that possibly represent its parental magma. The oceanic Rypdalen Shear Zone generally separates the two suites in the north, but several non-tectonic transitions from boninitic to tholeiitic signatures southwards advocate that the magmatism happened concurrently. The magmatic proximity between the suites, the hydrous magmatism and the absence of a silicic or calc-alkaline mature arc section, suggests that the Lyngen Gabbro formed in the Iapetus Ocean under conditions presently found in incipient arcs later emplaced as outer arc highs.  相似文献   

The use of bisnorhopane as a stratigraphic marker in the Oseberg Back Basin, North Viking Graben, Norwegian North Sea     

Birger Dahl 《Organic Geochemistry》2004,35(11-12):1551

This paper discusses the occurrence of 28,30-dinor-17α,18α,21β-hopane (bisnorhopane) in stratigraphically, fairly well preserved Viking Group sections from wells in local depressions in the North Viking Graben Area. The results show the presence of high relative amounts of bisnorhopane in the “Syn-rift sections”, whilst the “Post-rift sections” contain little or no bisnorhopane. Since most exploration wells are drilled on structural highs, primarily penetrating the “Post-rift Draupne”, this may explain why many analyzed source rock sections in this area contain little bisnorhopane.As a correlation of Draupne sections using the vertical, relative bisnorhopane distributions, it is suggested to be a potential stratigraphic marker for the area, indicating the presence of “Syn-rift Draupne” sediments.The relative bisnorhopane amounts follow a logarithmic reduction with depth and thermal maturity. The bisnorhopane signal is nearly extinguished at 3700 m depth at a maturity of R_o = 0.9–1.0%.  相似文献   

Can the diffuse double layer theory describe changes in hydraulic conductivity of compacted clays?   总被引：1，自引：0，他引：1  

Robrecht M. Schmitz 《Geotechnical and Geological Engineering》2006,24(6):1835-1844

Observations related to modifications of the hydraulic conductivity of compacted soils as a consequence of intentional compositional variation of the percolating fluid are often attributed vaguely to calculated changes in double layer thickness. The same calculated decrease or increase in double layer thickness is interpreted differently, depending on which (unconsciously held) boundary conditions authors take into account. The interpretations of different authors seem to be paradoxical only if the boundary conditions have not been mentioned. On the basis of a literature survey and own previously published test results the different boundary conditions have been grouped and divided into classes. With this division the interpretation of changes in double layer thickness will lead to unique interpretations and predictions of changes in hydraulic conductivity.  相似文献   

Stress-induced variations of remanent magnetism in Late Quaternary varved clay     

Birger Schmitz 《Earth and Planetary Science Letters》1984,69(2):422-426

A study of the remanent magnetism in Swedish varved clay shows that, even in varves that macroscopically appear to be undeformed, the paleomagnetic record may be seriously altered due to stress-induced deformation of the micro-fabric in the sediment.In the studied area disturbed clays were rather the rule than the exception, but undisturbed sediments were found at two sites, Järna II and III. This clay formed 10,200 years B.P. and shows a declination of about 30° east, a value that could be obtained thanks to excellent lateral control of the magnetism.  相似文献