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F. Karl 《Mineralogy and Petrology》1954,4(1-4):320-328
A transition between high and low temperature forms of plagioklase exists to which is probably connected a material replacement, similar to a “spilit” reaction, of more basic by more acidic plagioclase. These plagioklase changes are to be attributed to the same geological processes which produced the transitional conditions between extrusive and intrusive crystalline rock formation. Alpine metamorphoses caused low-temperature optical properties in the probably originally hightemperature plagioclase of eruptive rocks without changing the primary fabric of the rock. 相似文献
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Karl Beurlen 《International Journal of Earth Sciences》1968,58(2):713-734
Zusammenfassung Mit der heute wohl begründeten Annahme von Lageveränderungen der geotektonischen Großeinheiten während der Erdgeschichte ist die paläogeographische Rekonstruktion problematisch geworden, da sie nicht auf der Basis der heutigen geographischen Lagebeziehungen aufbauen kann. Auf der anderen Seite ist gerade die paläogeographische Rekonstruktion, die unvoreingenommen möglichst alle Einzeldaten der verschiedenen Spezialdisziplinen berücksichtigt, die Voraussetzung für eine kritische Analyse der wechselnden Lagebeziehungen. Gerade seine Problematik macht den paläogeographischen Rekonstruktionsversuch zum unentbehrlichen methodischen Hilfsmittel geologischer und geotektonischer Forschung — unter der Voraussetzung, daß man sich dabei nicht vom heutigen Kartenbild leiten läßt. An den Beispielen des Amazonas-Beckens, des Atlantischen Ozeans und der Paläogeographie Mittelamerikas—Westindiens werden diese Zusammenhänge dargelegt.
By the well-founded hypothesis of changes in the position of geotectonical major units during earth history, a paleogeographical reconstruction becomes problematical, since it cannot be based on the present geographical situation. On the other hand, it is above all the paleogeographical reconstruction which considers the greatest possible number of single data of the various branches of earth sciences, thus being the presupposition for a critical analysis of the changing position of the geotectonical units. By its complexity, the attempt of paleogeographical reconstruction is an indispensable methodical aid for geological and geotectonical research — under the condition that it is done independently of the actual geographical map. These correlations are demonstrated on the examples of the Amazon basin, the Atlantic Ocean and the paleogeography of Middle America and the West Indies.
Résumé L'hypothèse bien fondée des changements de position des blocs continentaux pendant l'histoire de la terre, rend problématique la réconstruction paléogéographique, puisque celle-ci ne peut pas se baser sur la situation géographique actuelle. De l'autre coté, c'est surtout la réconstruction paléogéographique qui tient compte des dates individuelles des branches géoscientifiques particulières, étant ainsi le fondement pour une analyse critique des changements de position des éléments tectoniques. Par son caractère problématique, l'essai d'une réconstruction paléogéographique est une aide indispensable pour la recherche géologique et géotectonique — sous la condition qu'on ne regard pas la figure des cartes modernes. L'auteur démontre ces relations par l'exemple du bassin des Amazones, de l'Océan atlantique et de la paléogéographie de l'Amérique centrale et des Indes occidentales.
Resumo A hipótese é bem fundamentada que, durante a história da terra aconteceram alterações da posiçào dos blocos continentais; em consequência disso a reconstrução palaogeográfica é um pouco problemática; pois não pode basear-se na configuração geográfica atual. Por outro lado, é exatamente a reconstrução paleogeográfica, baseada nas observações e experiências das diversas disciplinas geológicas, que constitui o único fundamento certo de uma análise das alterações consecutivas da posição das unidades geotectônicas. A tentativa da reconstrução paleogeográfica torna-se, dêste modo, um método indispensável para a pesquisa geológica e geotectônica, caso que a reconstrução paleogeográfica é executada independentemente da configuração geográfica atual. Estas relações são demonstradas pelos exemplos do desenvolvimento geológico da bacia do Amazonas, do Ozeano Atlântico e da América Central e das ilhas centralamericanas.
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Karl E. Havens 《Aquatic Sciences - Research Across Boundaries》1999,61(2):150-167
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Karl E. Garman Phil Wyss Mark Carlsen James R. Zimmerman Brian H. Stirm Thomas Q. Carney Robert Santini Paul B. Shepson 《Boundary-Layer Meteorology》2008,126(3):461-476
Aircraft-based vertical flux measurements fill a gap in the spatial domain for studies of biosphere–atmosphere exchange. To
acquire valid flux data, a determination of the deviation from the mean vertical wind, w′, is essential. When using aircraft platforms, flux measurements are subject to systematic and random errors from airflow
distortion caused by the lift-induced upwash ahead of the aircraft. Although upwash is typically considered to be a constant
quantity over periods used for calculating fluxes, it can vary significantly over short (and longer) periods due to changes
in aircraft lift. The characterization of such variations in upwash are of undeniable importance to flux measurements, especially
when real-time computations of w′ are required. In this paper, the variability in upwash was compared to the calculated upwash from the model of Crawford
et al. (Boundary-Layer Meteorol, 80:79–94, 1996) using data taken during a long-period (phugoid mode) free oscillation of
the aircraft. The cyclic variation of lift during the free oscillation offers an ideal scenario in which to acquire in-flight
data on the upwash that is present, as well as to test the capability of upwash correction models. Our results indicate that
while this model corrects for much of the mean upwash, there can be significant variations in upwash on a time scale that
is important to flux measurements. Our results suggest that use of the measured load factor could be an easily implemented
operational constraint to minimize uncertainty in w′ due to changing upwash from changing aircraft lift. We estimate, using the phugoid data, and from variations in aircraft
attitude and airspeed in flux-measurement configuration, that the uncertainty in w caused by variable upwash is approximately ± 0.05 m s−1. 相似文献