Paleoenvironmental evolution of the Paratethys in the Slovenian Basin during the Late Paleogene     

Gerhard?SchmiedlEmail author  Maria?Scherbacher  Angela?A.?Bruch  Bogomir?Jelen  James?H.?Nebelsick  Christoph?Hemleben  Volker?Mosbrugger  Helena?Rifelj 《International Journal of Earth Sciences》2002,91(1):123-132

Several sections from the uppermost Eocene and Oligocene of northern Slovenia have been investigated with respect to sedimentary facies, foraminiferal assemblages, stable isotopes, carbonate microfacies, and palynology. The main objective was to reconstruct the paleoenvironmental history of the Paleogene Paratethys in this region of the eastern Alpine realm. The sediments exhibit a transgressive succession beginning with conglomerates, sandstones, and mudstones of fluvial and lacustrine origin followed by carbonates and muddy marls indicating marine conditions. The foraminiferal faunal changes from brackish to shallow marine to deeper marine assemblages and the distribution of the palynofloras corroborate the sedimentological results. Microfacies analysis of the limestones shows a wide variation of shallow water, generally mud-rich facies dominated by coralline algae, foraminifera, and corals. Microfaunas adapted to low-oxygen conditions indicate temporal sluggish bottom-water circulation which can be associated with high fresh-water fluxes. These results are discussed as reflecting both the global sea-level rise during the Early Oligocene and the regional tectonic and climatic evolution.  相似文献   

Velocity-Porosity Relationships: Predictive velocity model for cemented sands composed of multiple mineral phases.     

Mark A. Knackstedt  Christoph H. Arns  W. Val Pinczewski 《Geophysical Prospecting》2006,54(2):237-237

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GIOVE-A initial signal analysis     

Oliver Montenbruck  Christoph Günther  Sebastian Graf  Miquel Garcia-Fernandez  Johann Furthner  Hanspeter Kuhlen 《GPS Solutions》2006,10(2):146-153

In late December 2005 the GIOVE-A test satellite was launched by the European Space Agency (ESA) to secure the frequencies for the Galileo system and to provide a platform for testing the new navigation signals. We performed an initial assessment of these signals using the 30 m deep space antenna of the DLR ground station in Weilheim (Germany). The antenna gain raised the signals above the noise level, thus allowing a detailed analysis even without knowledge of the ranging codes. The present paper covers the analysis of the L1/E1 signals, which includes a discussion of the spectrum, the time domain signal and a decoding of the spreading codes for the Open Service.  相似文献   

Scalar Similarity for Relaxed Eddy Accumulation Methods     

Johannes Ruppert  Christoph Thomas  Thomas Foken 《Boundary-Layer Meteorology》2006,120(1):39-63

The relaxed eddy accumulation (REA) method allows the measurement of trace gas fluxes when no fast sensors are available for eddy covariance measurements. The flux parameterisation used in REA is based on the assumption of scalar similarity, i.e., similarity of the turbulent exchange of two scalar quantities. In this study changes in scalar similarity between carbon dioxide, sonic temperature and water vapour were assessed using scalar correlation coefficients and spectral analysis. The influence on REA measurements was assessed by simulation. The evaluation is based on observations over grassland, irrigated cotton plantation and spruce forest.Scalar similarity between carbon dioxide, sonic temperature and water vapour showed a distinct diurnal pattern and change within the day. Poor scalar similarity was found to be linked to dissimilarities in the energy contained in the low frequency part of the turbulent spectra ( < 0.01 Hz).The simulations of REA showed significant change in b-factors throughout the diurnal course. The b-factor is part of the REA parameterisation scheme and describes a relation between the concentration difference and the vertical flux of a trace gas. The diurnal course of b-factors for carbon dioxide, sonic temperature and water vapour matched well. Relative flux errors induced in REA by varying scalar similarity were generally below ± 10%. Systematic underestimation of the flux of up to − 40% was found for the use of REA applying a hyperbolic deadband (HREA). This underestimation was related to poor scalar similarity between the scalar of interest and the scalar used as proxy for the deadband definition.  相似文献   

Flux contribution of coherent structures and its implications for the exchange of energy and matter in a tall spruce canopy   总被引：2，自引：5，他引：2  

Christoph Thomas  Thomas Foken 《Boundary-Layer Meteorology》2007,123(2):317-337

The flux contribution of coherent structures to the total exchange of energy and matter is investigated in a spruce canopy of moderate density in heterogeneous, complex terrain. The study deploys two methods of analysis to estimate the coherent exchange: conditional averages in combination with wavelet analysis, and quadrant analysis. The data were obtained by high-frequency single-point measurements using sonic anemometers and gas analysers at five observation heights above and within the canopy and subcanopy, and represent a period of up to 2.5 months. The study mainly addresses the momentum transfer and exchange of sensible heat throughout the roughness sublayer, while results are provided for the exchange of carbon dioxide and water vapour above the canopy. The magnitude of the flux contribution of coherent structures largely depends on the method of analysis, and it is demonstrated that these differences are attributed to differences in the sampling strategy between the two methods. Despite the differences, relational properties such as sweep and ejection ratios and the variation of the flux contribution with height were in agreement for both methods. The sweep phase of coherent structures is the dominant process close to and within the canopy, whereas the ejections gain importance with increasing distance to the canopy. The efficiency of the coherent exchange in transporting scalars exceeds that for momentum by a factor of two. The occurrence of coherent structures results in a flux error less than 4% for the eddy-covariance method. Based on the physical processes identified from the analysis of the ejection and sweep phases along the vertical profile in the roughness sublayer, a classification scheme for the identification of exchange regimes is developed. This scheme allows one to estimate the region of the canopy participating in the exchange of energy and matter with the above-canopy air under varying environmental conditions.  相似文献   

Landscape governance: The “politics of scale” and the “natural” conditions of places     

Christoph Görg 《Geoforum》2007,38(5):954-966

Governance has become an iridescent concept in recent years. The term is widely used in almost all social-science disciplines as well as in the political process. The intention of this paper is not so much to clarify these sometimes vague meanings but to highlight some characteristics of environmental governance connected with the restructuring of the spatial dimensions of politics. It starts from the assumption that the quest for multi-level decision making is particularly pressing for environmental governance. However, multi-level governance raises concern about the constitution of various spatial levels and their relationships with each other, as discussed under the term of “politics of scale”. Moreover, it is argued that for environmental governance the spatial reference is strongly connected with another challenge, which concerns the question of how to deal with the biophysical conditions of particular places. The term landscape governance is introduced to tackle this question without referring to an ontologically given space. Thus, landscape governance deals with the interconnections between socially constructed spaces (the politics of scale) and “natural” conditions of places. For this task, the concept of societal relationships with nature is introduced and applied to the term “landscape” as a bridging concept between social and natural sciences. The paper illustrates the approach of landscape governance with examples of problem-oriented interdisciplinary research at the UFZ-Centre for Environmental research in Leipzig, Germany.  相似文献   

Das Geologen-Archiv der Geologischen Vereinigung     

M. Schwarzbach 《International Journal of Earth Sciences》1980,69(3):1013-1015

Ohne Zusammenfassung  相似文献   

The tidal stream in the German Bight     

Christoph Brockmann  Wolfgang Lange  Dr. Ekkehard Mittelstaedt  Kai C. Soetje 《Ocean Dynamics》1981,34(2):56-60

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Temperatur-Änderungen in der Erdgeschichte     

Prof. Dr. Martin Schwarzbach 《International Journal of Earth Sciences》1976,65(1):820-844

This paper on “Temperature changes in earth-history” is an extension of a lecture given as an introduction to a section of equal title on the annual meeting of the Geologische Vereinigung, March 1976, in Hannover. The general development of paleoclimatological research in the last 300 years is represented on two diagrams (fig. 1–2) showing also the part of different climatic indicators. Otherwise, however, mostly new results and problems of the last years are treated (mainly papers since 1973; references of older literature are to be found in the 3^rd edition of the author's book on “Climates of the Past” = “Klima der Vorzeit”, Enke/Stuttgart 1974). This paper refers a) to some short comments on certain climatic indicators as diamictites (a similar term isSchermerhorn's “mixtite”, but “diamictite” is 6 years older and has therefore priority to “mixtite”) and “stellate nodules” (in the chapter “Mesozoic”) indicating perhaps cool climate in the Arctic. - b) Some great ice-ages are briefly discussed: Huronian (very important because of its old age); Late Proterozoic (“Eocambrian”) with many problems on account of its pretended worldwide extension. but with many uncertainities (partly pseudotillites, inconsistent paleomagnetic poles, combination of tillites with dolomites etc.); Permo-Carboniferous (many hypothesises up to 1975 try to explain the pretended “equatorial” position of tillites); Cenozoic ice-age (once “Quaternary” ice-age), with table 1 indicating some possibilities to evaluate the beginning of glaciations in Tertiary time (fig. 4). Why does glaciation start in Antarctica in the Tertiary? (Not or not only on account of drift via South Pole, but perhaps because of high relief and changes in global paleogeography). — c) Diagram of the great ice-ages in earth-history (fig. 6 b): it probably shows not all ice-ages but only the known ones indicating their maxima (i. e. times when inlandice extended to middle latitudes). This curve is probably essentially correct back to 300–400 m. y. yet especially the Precambrian time is still mostly paleoclimatic noman's-land. It is not possible to fix beginning and end of the Pre-Tertiary ice-ages exactly but at any rate the “akryogene” climates lasted longer than the “kryogene” ones (“kryogene” defined as climate with “much ice” [“pleistokryogene”], “akryogene” not as climate “without ice” but as climate with “a little ice” [“oligokryogene”]). - d) Periodicities in the temperature history: before exact dates were available (especially for Late Proterozoic and Huronian ice-ages) and before the Sahara glaciation of the Old Paleozoic was known, a periodicity of 250–300 m. y. was likely to exist. Therefore relations to the “Galactic year” were reasonable, stimulating attempts to find out plausible mechanisms for such a relation. But now, such a periodicity seems unlikely to exist (and much more one of 155 m. y., supposed byWilliams). The relative constancy of global earth temperatures over at least more than 2 billion years is more striking than their variations, though regionally the depressions may be very conspicious (in the middle, “sensitive” latitudes). Such depressions, however, are triggered by very small climatic changes on account of the existence of a hydrosphere with temperatures very favorable for a transformation of water into ice and vice versa. No other celestial body of our solar system has these optimal conditions with the consequences of occasional initiation of ice-ages. Ice ages, so to speak, are an inherited pecularity of the earth. The earth is the only “Ice-age Planet”. Under these circumstances, relatively small factors may cause ice-ages: multilateral origin of climatic changes. The most efficient parameters may be paleogeographic variations (relief etc. inclusive continental drift). Some comments are made on the radiation curves reflecting not the direct cause of glacials and interglacials but perhaps shorter climatic variations as they appear possibly in the curves of ocean temperatures (Emiliani etc.). Volcanic ashes seem not to have any farreaching influence on global temperatures; at least it is geologically impossible to support appropriate hypothesises by observations on continental volcanic sequences. The number of ash-layers in deep-sea cores may reveal sounder arguments though much more observations are needed to corroborate this supposition. — Table 2 gives a summary of the primary (planetary), secondary (multilateral) and — in special situations — tertiary “autocyclic” causes of climatic changes. Table 3 focuses on autocycles i. e. mechanisms which run. off automatically and could have caused the regular climatic variations in the Late Pleistocene with the classic glacialinterglacial sequence (not known from the older Quaternary or Pre-Tertiary ice-ages). In my opinion the most probable hypothesises on autocycles are those which were founded on wide extending subarctic continents of the northern hemisphere (qualified for the formation of large inlandice) in combination with mighty oceanic heat storage (Stokes, D. P. Adam, R. E. Newell).  相似文献   

Granite intruding into Granodiorite: An example from the Damara Belt,South West Africa     

Dr. Christoph Hoffmann 《International Journal of Earth Sciences》1977,66(1):465-477

Until now (Smith, 1965) it was thought that in the central Damara Belt, South West Africa, the Red Granite and the Salem Granodiorite are two magmatic bodies separated by (essentially) marbles. Three places were discovered, where the marbles are missing; in all three places the Red Granite intrudes the Salem Granodiorite. Experimental melting done with samples from two of these localities allows to appraise the likely conditions during the intrusion of the Red Granite (680° C, 4 kb H₂O-pressure).The White Granites — until now thought to be late or post kinematic — are a geologically heterogeneous group, at least in one place such an intrusion precedes that of the Red Granite.

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Zusammenfassung Bis jetzt dachte man (Smith, 1965) daß im Zentralbereich des Damara-Orogens, Südwest Afrika, der Rote Granit und der Salem Granodiorit zwei magmatische Körper wären, die überall von (im wesentlichen) Marmoren getrennt seien. Es wurden drei Gegenden entdeckt, an denen die Marmore fehlen; an allen drei Stellen intrudiert der Rote Granit in den Salem Granodiorit. Schmelz-Experimente mit Proben von zwei dieser Lokalitäten erlauben die Bedingungen abzuschätzen, die während der Intrusion des Roten Granites geherrscht haben (680° C, 4 kb H₂O-Druck).Die Weißen Granite — von denen man bis jetzt glaubte, sie seien spät-oder nachkinematisch — sind eine geologisch heterogene Gruppe. Mindestens an einer Stelle geht eine Intrusion der Weißen Granite derjenigen der Roten Granite voraus.

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Résumé Jusqu'à présent (Smith, 1965) on a pensé que dans la zone centrale de l'orogène de Damara (Sud-Ouest Africain) le Granite Rouge et la Granodiorite de Salem étaient deux plutonites séparées partout par des couches de marbres. On a découvert trois endroits où les marbres n'existent pas et où le Granite Rouge forme des intrusions recoupant la Granodiorite de Salem.Des essais de fusibilité sur des échantillons provenant de deux de ces localité permettent d'estimer les conditions d'intrusion du Granite Rouge (680° C avec des pressions H₂O de 4–5 kb).Les Granites blancs (acceptés jusqu'à présent comme tardi orogéniques) forment géologiquement une groupe hétérogène. En un endroit au moins, une intrusion de Granite blanc est recoupée par une intrusion du Granite Rouge, plus jeune.

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