Reply to comments by L. Michon and O. Merle on “Evolution of the European Cenozoic Rift System: interaction of the Alpine and Pyrenean orogens with their foreland lithosphere” by P. Dèzes, S.M. Schmid and P.A. Ziegler, Tectonophysics 389 (2004) 1–33   总被引：1，自引：0，他引：1  

Pierre Dzes  Stefan M. Schmid  Peter A. Ziegler 《Tectonophysics》2005,401(3-4):257-262

  相似文献   

Combined Earth orientation parameters based on homogeneous and continuous VLBI and GPS data   总被引：1，自引：3，他引：1  

Daniela Thaller  Manuela Krügel  Markus Rothacher  Volker Tesmer  Ralf Schmid  Detlef Angermann 《Journal of Geodesy》2007,81(6-8):529-541

The CONT02 campaign is of great interest for studies combining very long baseline interferometry (VLBI) with other space-geodetic techniques, because of the continuously available VLBI observations over 2 weeks in October 2002 from a homogeneous network. Especially, the combination with the Global Positioning System (GPS) offers a broad spectrum of common parameters. We combined station coordinates, Earth orientation parameters (EOPs) and troposphere parameters consistently in one solution using technique- specific datum-free normal equation systems. In this paper, we focus on the analyses concerning the EOPs, whereas the comparison and combination of the troposphere parameters and station coordinates are covered in a companion paper in Journal of Geodesy. In order to demonstrate the potential of the VLBI and GPS space-geodetic techniques, we chose a sub-daily resolution for polar motion (PM) and universal time (UT). A consequence of this solution set-up is the presence of a one-to-one correlation between the nutation angles and a retrograde diurnal signal in PM. The Bernese GPS Software used for the combination provides a constraining approach to handle this singularity. Simulation studies involving both nutation offsets and rates helped to get a deeper understanding of this singularity. With a rigorous combination of UT1–UTC and length of day (LOD) from VLBI and GPS, we showed that such a combination works very well and does not suffer from the systematic effects present in the GPS-derived LOD values. By means of wavelet analyses and the formal errors of the estimates, we explain this important result. The same holds for the combination of nutation offsets and rates. The local geodetic ties between GPS and VLBI antennas play an essential role within the inter-technique combination. Several studies already revealed non-negligible discrepancies between the terrestrial measurements and the space-geodetic solutions. We demonstrate to what extent these discrepancies propagate into the combined EOP solution.  相似文献   

Über synthetischen Kobaltchrysotil und seine Beziehungen zu anderen Solenosilikaten     

Prof. Walter Noll  Heinrich Kircher  Willi Sybertz 《Contributions to Mineralogy and Petrology》1960,7(4):232-241

Ohne Zusammenfassung  相似文献   

The effects of volcanic ash on COSPEC measurements     

R. J. Andres  J. W. Schmid 《Journal of Volcanology and Geothermal Research》2001,108(1-4)

Data from a series of laboratory experiments show the relationships between measured correlation spectrometer (COSPEC) sulfur-dioxide (SO₂) burdens, automatic gain control (AGC) deflections, and visible wavelength opacities in ash-laden plumes. The data show that the COSPEC reliably measures (within a 10% accuracy) SO₂ burdens up to AGC deflections of 2 V and visible wavelength opacities of 50%. Beyond these limits, the under measurement of the SO₂ burden is not well constrained. During typical COSPEC runs, these limits are rarely violated. The 10% error introduced by measuring ash-laden plumes is acceptable because the error is small relative to other error sources associated with the technique, especially plume velocity; and the error is correctable which allows for a wider range of plume conditions to be measured.These results imply that the densest SO₂ concentrations near the volcanic source can be measured. This is important so that SO₂ is not lost from the volcanic plume due to physical and chemical processes and that measurements are conducted under maximum signal to noise ratios.  相似文献   

A Three-Dimensional Backward Lagrangian Footprint Model For A Wide Range Of Boundary-Layer Stratifications   总被引：5，自引：3，他引：5  

N. Kljun  M.W. Rotach  H.P. Schmid 《Boundary-Layer Meteorology》2002,103(2):205-226

We present a three-dimensional Lagrangian footprint model with the ability to predict the area of influence (footprint) of a measurement within a wide range of boundary-layer stratifications and receptor heights. The model approach uses stochastic backward trajectories of particles and satisfies the well-mixed condition in inhomogeneous turbulence for continuous transitions from stable to convective stratification. We introduce a spin-up procedure of the model and a statistical treatment of particle touchdowns which leads to a significant reduction of CPU time compared to conventional footprint modelling approaches. A comparison with other footprint models (of the analytical and Lagrangian type) suggests that the present backward Lagrangian model provides valid footprint predictions under any stratification and, moreover, for applications that reach across different similarity scaling domains (e.g., surface layer to mixed layer, for use in connection with aircraft measurements or with observations on high towers).  相似文献   

La freibergite du gisement de plomb-zinc de Praz-Jean (Valais,Suisse)     

E. A. Schmid  F. C. Jaffé  M. Burri 《Mineralium Deposita》1990,25(3):198-204

The lead-zinc-silver bearing vein of Praz-Jean (Vallis, Switzerland) is hosted in a suite of metamorphic rocks, most likely of Palaeozoic age. Sphalerite, galena and sulfosalts (freibergite and boulangérite) are its main ore-forming minerals. The results of the microprobe investigation indicate that the silver is contained in a freibergite of the following composition (weight percent): Cu 23.0, Ag 23.0, Fe 4.9, Zn 1.9, As 1.0, Sb 26.9, S 23.0, and not in an argentian galena as it was believed. The mineral previously described as jamesonite (Pb₄FeSb₆S₁₄) is in reality a boulangérite (Pb₅Sb₄S₁₁). The mineralogical and metallogenetic characteristics of the freibergite of Praz-Jean are discussed in relation to those of other ore deposits in which this mineral is of interest.

---

Resumé Le filon de plomb-zinc-argent de Praz-Jean (Valais, Suisse), se trouve dans un encaissant composé de roches métamorphiques vraisemblablement d'âge Paléozoïque. Ses minéraux constitutifs, qui ont été étudiés en détail à la microsonde, appartiennent à une suite classique de sulfures à blende et galène dominantes, et de sulfosels (freibergite, boulangérite). L'argent du gisement n'est pas contenu dans une galène argentifère comme on le croyait auparavant, mais dans une freibergite de composition pondérale: Cu 23,0, Ag 23,0, Fe 4,9, Zn 1,9, As 1,0, Sb 26,9, S 23,0. Le minéral décrit précédemment comme jamesonite (Pb₄FeSb₆S₁₄) est en réalité une boulangérite (Pb₅Sb₄S₁₁). La freibergite de Praz-Jean est comparée du point de vue minéralogique et gîtologique à des freibergites d'autres gisements dans lesquels la freibergite joue un rôle important.

  相似文献   

Source areas for scalars and scalar fluxes   总被引：19，自引：2，他引：19  

H. P. Schmid 《Boundary-Layer Meteorology》1994,67(3):293-318

The spatial resolution of meteorological observations of scalars (such as concentrations or temperature) and scalar fluxes (e.g., water-vapour flux, sensible heat flux) above inhomogeneous surfaces is in general not known. It is determined by the surface area of influence orsource area of the sensor, which for sensors of quantities that are subject to turbulent diffusion, depends on the flow and turbulence conditions.Functions describing the relationship between the spatial distribution of surface sources (or sinks) and a measured signal at height in the surface layer have been termed thefootprint function or thesource weight function. In this paper, the source area of levelP is defined as the integral of the source weight function over the smallest possible domain comprising the fractionP of the total surface influence reflected in the measured signal. Source area models for scalar concentration and for passive scalar fluxes are presented. The results of the models are presented as characteristic dimensions of theP=50% source areas (i.e., the area responsible for 50% of the surface influence): the maximum source location (i.e., the upwind distance of the surface element with the maximum-weight influence), the near and the far end of the source area, and its maximal lateral extension. These numerical model results are related directly to non-dimensional surface-layer scaling variables by a non-linear least squares method in a parameterized model which provides a user-friendly estimate of the surface area responsible for measured concentrations or fluxes. The source area models presented here allow conclusions to be made about the spatial representativeness and the localness (these terms are defined in the text) of flux and concentration measurements.  相似文献   

Superplastic flow in finegrained limestone   总被引：1，自引：0，他引：1  

S.M. Schmid  J.N. Boland  M.S. Paterson 《Tectonophysics》1977,43(3-4)

Creep of Solnhofen limestone at temperatures between 600° and 900° C was found to fall into three different flow regimes: regime 1 with an exponential stress-dependence of strain rate, regime 2 with power-law creep and n ~ 4.7 and finally a superplastic regime 3 with n ~ 1.7. Within the superplastic regime the creep behaviour is strongly grain-size dependent, the strain rate increasing markedly with decrease in grain size at a given stress. Microstructural observations indicate that in regimes 1 and 2 intracrystalline plasticity is dominant whereas the superplastic regime is characterized by grain-boundary sliding. The crystallographic preferred orientation within the superplastic regime is weaker and of different geometry when compared with that in flow regimes 1 and 2. In a discussion on the deformation mechanisms it is suggested that flow regimes 1 and 2 are regimes of dis location creep in which the rate controlling step is diffusion assisted; for the superplastic regime existing models of grain-boundary sliding are compared with the observations Finally, the tectonophysical importance of superplasticity is discussed and by extra polating the observed creep behaviour to geological strain rates it is found that super plasticity in rocks is to be expected under a wide range of conditions, particularly at smal grain sizes.  相似文献   

Population growth and costs of education in developing countries: Châu Ta, Ngog (1972): 313 S., 182 tables, 36 textfig., Unesco, Paris: International Institute for Educational Planning. US$7, £2.35, 28 F     

Willi Schulze 《Geoforum》1975,6(3-4)

  相似文献   

Multiple zircon growth and recrystallization during polyphase Late Carboniferous to Triassic metamorphism in granulites of the Ivrea Zone (Southern Alps): an ion microprobe (SHRIMP) study   总被引：92，自引：2，他引：92  

G. Vavra  Dieter Gebauer  Rolf Schmid  William Compston 《Contributions to Mineralogy and Petrology》1996,122(4):337-358

 Zircons from a metasedimentary and a meta-igneous quartz-feldspar granulite from the Val Sesia and Val Mastallone area of the Ivrea Zone (Southern Alps) differ in their response to granulite facies metamorphism with respect to crystal morphology and U/Pb ages. Detrital zircons in the metasediment developed an isometric overgrowth by the addition of Zr derived mainly from co-existing minerals, most probably biotite, decomposing during anatectic melting. The overgrowth started in the pelitic layer of the metasediment in the Late Carboniferous at approximately 296 Ma, significantly earlier than in the adjacent psammitic layer where it started only at 261 ± 4 Ma (95% confidence level). These ages are ascribed to the differential initiation of anatexis in the two layers. The delay of melting in the psammitic layer was probably due to the different position and less steep slope of its solidus in P-T-space, as compared to the solidus in the pelitic layer. Accordingly, the melting in the psammitic layer at 261 Ma was initiated by a thermal pulse and/or by a decompression event. Decompression melting is supported by a characteristic shell morphology of the zircon overgrowth in the psammitic layer, which might have grown under shear movements during high-temperature extensional faulting. The typically magmatic zircon population of the meta-igneous granulite crystallized at 355 ± 6 Ma (95% confidence level). The morphology of the zircons and the chemistry of the rock suggest that the magma was calcalkaline. A minor subpopulation of crystals is morphologically similar to the zircons in the pelitic layer of the metasediment. This points to the admixture of a minor sediment component and, thus, to a largely volcaniclastic origin of the protolith. In contrast to the detrital zircons in the metasediment, the magmatic zircons show rare and little overgrowth and, instead, have been strongly resorbed by anatectic melt. In addition, they became partially recrystallized and the rejuvenated ages from the most thoroughly recrystallized domains indicate that the rock was subject to prograde metamorphism after 279 Ma. This may correspond to the regional temperature increase prior to the climax of metamorphism or to a local thermal pulse due to nearby mafic intrusions. An Upper Triassic event at 226 ± 5 Ma is reflected by distinct peripheral zones in the overgrowths of some zircons in the metapelite. These are interpreted as a second metamorphic pulse, possibly induced by the infiltration of fluids. Received: 2 June 1995 / Accepted: 15 September 1995  相似文献