Über den Schwermineralgehalt von anstehendem und verwittertem Brockengranit nördlich St. Andreasberg     

Dr. Horst Piller 《Contributions to Mineralogy and Petrology》1951,2(6):523-537

Zusammenfassung Es wird der Gehalt an durchsichtigen Schwermineralen im anstehenden Granit und seinen Verwitterungsprodukten am Südrand des Brockengranitmassivs nördlich St. Andreasberg quantitativ untersucht.Die Korngrößenverteilung einzelner Schwerminerale im anstehenden und verwitterten Gestein wird angeführt. Dabei werden Rückschlüsse auf ihre mechanische und chemische Stabilität gezogen. und Zirkon hier fast nurmechanisch beeinflußbar sind.Die Verwitterung begünstigt die Bildung von Anatas, Epidot und vielleicht Brookit.Die Ausbildung der beschriebenen Schwermineralfamilie scheint das Ergebnis pneumatolytischer Bildungsbedingungen und hydrothermal-autometamorpher Umwandlung des Granits zu sein und erfährt letztlich eine Wandlung in situ durch die Verwitterung.  相似文献   

Regional distribution and temporal trends of some contaminants in the water of the Baltic Sea     

Lutz Brügmann  Horst Gaul  Karl-Heinz Rohde  Udo Ziebarth 《Ocean Dynamics》1991,44(4):161-184

During a cruise on board RV Gauss in May/June 1988, joint investigations into organochlorine compounds, dissolved trace metals, petroleum hydrocarbons and basic hydrography were carried out at representative stations of the Baltic Monitoring Programme (BMP). The aim of the cruise was to study distribution patterns and — using previous data — to establish temporal trends if at all discernible.Each group of contaminants investigated showed specific characteristics, with differences even between compounds within the same group. The differences are due to:

–	- the partition of contaminants between dissolved and adsorbed form;
–	- the response to redox conditions;
–	- the influence of microbial decay, organic production or changes in speciation.

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Observations of Comet 9P/Tempel 1 around the Deep Impact event by the OSIRIS cameras onboard Rosetta     

Horst Uwe Keller  Sonia Fornasier  Stubbe F. Hviid  Jörg Knollenberg  Miriam Rengel  Gabriele Cremonese  Detlef Koschny  Ekkehard Kührt  Holger Sierks  Cesare Barbieri  Hans Rickman  Michael F. A'Hearn  Maria-Antonella Barucci  Vania da Deppo  Björn J.R. Davidsson  Stefano Debei  Fritz Gliem  José J. Lopez Moreno  Giampiero Naletto  Angel Sanz Andrés 《Icarus》2007,187(1):87-103

The OSIRIS cameras on the Rosetta spacecraft observed Comet 9P/Tempel 1 from 5 days before to 10 days after it was hit by the Deep Impact projectile. The Narrow Angle Camera (NAC) monitored the cometary dust in 5 different filters. The Wide Angle Camera (WAC) observed through filters sensitive to emissions from OH, CN, Na, and OI together with the associated continuum. Before and after the impact the comet showed regular variations in intensity. The period of the brightness changes is consistent with the rotation period of Tempel 1. The overall brightness of Tempel 1 decreased by about 10% during the OSIRIS observations. The analysis of the impact ejecta shows that no new permanent coma structures were created by the impact. Most of the material moved with . Much of it left the comet in the form of icy grains which sublimated and fragmented within the first hour after the impact. The light curve of the comet after the impact and the amount of material leaving the comet ( of water ice and a presumably larger amount of dust) suggest that the impact ejecta were quickly accelerated by collisions with gas molecules. Therefore, the motion of the bulk of the ejecta cannot be described by ballistic trajectories, and the validity of determinations of the density and tensile strength of the nucleus of Tempel 1 with models using ballistic ejection of particles is uncertain.  相似文献   

The Footprint for Estimation of Atmosphere-Surface Exchange Fluxes by Profile Techniques   总被引：3，自引：0，他引：3  

T. W. Horst 《Boundary-Layer Meteorology》1999,90(2):171-188

The flux footprint, that is the contribution per unit emission from each element of the upwind surface area to measurement of the vertical flux of a passive scalar, is calculated for fluxes estimated by micrometeorological profile techniques. It is found that the upwind extent of the footprint for concentration-profile flux estimates is similar to that of the footprint for eddy-covariance flux measurements, when the eddy-covariance measurement is made at a height equal to the arithmetic mean of the highest and lowest profile measurement heights for stable stratification or the geometric mean for unstable stratification. The concentration-profile flux footprint depends on the ratio of the highest to the lowest measurement height, but is insensitive to the number of measurement levels. The concentration-profile flux footprint extends closer to the measurement location than does the 'equivalent eddy-covariance flux footprint, and the difference becomes more pronounced as the ratio of the profile measurement heights increases. The flux footprint for the Bowen-ratio technique is identical to that for a two-level profile measurement only for very limited circumstances. In the more general case, a flux footprint cannot be defined for the Bowen-ratio technique and the uniform upwind fetch required for representative flux measurements depends on the specific spatial distribution of surface fluxes.  相似文献   

Untersuchungen zur Morphologie des Schelfrandes vor Mozambique nordöstlich der Sambesi-Mündung     

Dr. Johannes Ulrich  Dr. Horst Pasenau 《Ocean Dynamics》1973,26(5):216-225

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NIZUSE: a deep seismic reflection line in north-eastern Germany     

Wolfgang Horst  Michael Börngen  Ernst R. flueh 《International Journal of Earth Sciences》1994,83(1):161-169

Out of a dense network of seismic reflection lines for hydrocarbon exploration in the North-east German Basin, several lines were recorded to 12 s TWT to obtain information about the structure of the crust and the crust-mantle transition. One of these profiles is presented here. This stretches for 110 km in a NNE direction between Neustrelitz and the island of Usedom. It reaches from the External Variscides in the south across the North German Massif into the Rügen-Pomorze Terrane in the Baltic Sea. Below Cenozoic-Mesozoic-Paleozoic cover with clear reflections down to base Zechstein, the reflectivity varies considerably with depth and also laterally. The Paleozoic and Precambrian sediments and basement are generally void of reflections, but the lower crust and the Moho show strong reflections. To the north the reflectivity decreases, and the Moho depth increases to beyond the bottom of the record section at 12 s. There are no direct indications for deep-reaching faults such as the Trans-European Fault in the north. The North German Massif acted as a ramp towards the Variscan Orogeny, similar to the London-Brabant Massif further west.  相似文献   

A Pan-African alkaline pluton intruding the Saramuj Conglomerate,south-west Jordan     

Ghaleb Jarrar  Horst Wachendorf  Dieter Zachmann 《International Journal of Earth Sciences》1993,82(1):121-135

The geological setting, petrography and bulk mineral chemistry of a monzodiorite and a presumably consanguineous megaporphyry with large (up to 25 cm) labradorite megacrysts, both intruding the upper Proterozoic Saramuj Conglomerate in south-west Jordan (south eastern shore of the Dead Sea), were examined. The crystallization temperatures of the monzodiorite and the megaporphyry as determined from pyroxene thermometry and supported by contact metamorphic mineralogy are about 700 and 900°C, respectively. The intrusion depth of the monzodiorite is about 3–4 km. The monzodiorite was emplaced in the Saramuj Conglomerate at about 595 + 2 Ma ago according to Rb/Sr and U/Pb age determinations.The stratigraphic positions of the monzodiorite, megaporphyry and their host rock (the Saramuj Conglomerate) were compared with time-equivalent lithologies in the Arabian-Nubian Shield. Correspondence to: H. Wachendorf  相似文献   

Age determinations in the Precambrian basement of the Wadi Araba area,southwest Jordan     

Ghaleb Jarrar  Albrecht Baumann  Horst Wachendorf 《Earth and Planetary Science Letters》1983,63(2):292-304

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Zum Problem der Schichtlücken im Devon der Sierra Morena (Spanien)     

Dr. Horst Puschmann 《International Journal of Earth Sciences》1967,56(1):528-542

Zusammenfassung Im Devon der nördlichen Sierra Morena und der Sierra de San Pedro treten Schichtlücken auf, die in den untersuchten Mulden ein unterschiedliches Ausmaß erreichen. Das Mitteldevon konnte nirgends nachgewiesen werden. Das Oberdevon folgt unmittelbar über unterdevonischen oder auch silurischen Schichten. Im südlichen Arbeitsgebiet kann sogar das Oberdevon fehlen, so daß unterkarbonische Sedimente über silurischen und älteren Schichten liegen.Für das Fehlen von Oberdevon kann Schwellenbildung und damit verbundene Abtragung vermutet werden. Die Schichtlücken im Unter- und Mitteldevon der übrigen Gebiete scheinen dagegen durch Unterbrechung der Sedimentzufuhr erklärbar zu sein.

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In the Devonian of northern Sierra Morena and Sierra de San Pedro there exist stratigraphical breaks of different amount in the investigated troughs. No Middle Devonian could be found. Upper Devonian rests directly upon Lower Devonian or Silurian rocks. Due to the occasional lack of Upper Devonian in the southern area under discussion even sediments of Lower Carboniferous age may superpose Silurian and older deposits.The absence of Upper Devonian is supposed to be caused by development of ridges and their erosion. However, stratigraphical breaks during Lower and Middle Devonian in the other areas seem to be explicable by non-deposition.

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Résumé Dans les synclinals étudiés du Dévonien de la Sierra Morena septentrionale et de la Sierra de San Pedro il y a des lacunes stratigraphiques atteignant de différentes ampleurs. Dévonien moyen ne fut nulle part observé. Dévonien supérieur suit immédiatement les couches du Dévonien inférieur ou bien du Silurien. Dans le secteur méridional il y a même des lacunes stratigraphiques du Dévonien supérieur, et les sédiments du Carbonifère inférieur reposent sur le Silurien ou sur des couches plus anciennes.Il est possible qu'un soulèvement d'un paléorelief accompagné de l'érosion soit responsable de la lacune du Dévonien supérieur. Quant aux lacunes du Dévonien inférieur et moyen des autres régions elles sont plutôt à expliquer par non-déposition.

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Stratigraphische Untersuchungen im Paläozoikum des Montseny (Katalonien/Spanien)     

Dr. Horst Puschmann 《International Journal of Earth Sciences》1968,57(3):1066-1088

The Catalonian Coast Bange and Inner Bange are the connecting link between the East-Pyrenees in the North and the Celtiberic Chains in the Southeast. During the Paleozoic the Catalonian Ranges differ from both areas by extreme eugeosynclinal conditions with very low rates of sedimentation. Similar conditions in the Hercynian of Spain are to be found in the “pelagic” areas of the southwestern part of the Sierra Morena from upper Ordovician to Lower Carboniferous times. Based on the mapping of the Avencó-Valley (a part of the Montseny-Mountains/Catalonia) the Paleozoic layers are described and a stratigraphic subdivision is worked out. The conformable sequence begins in the upper Ordovician (Caradoc) and continues to the Visean. Buntsandstein is unconformably overlying the Paleozoic. The Ordovician/Silurian boundary is determined by Graptolithes; the Silurian/Devonian boundary is located within a sequence of Orthoceras-limestone as elsewhere in the Catalonian Range. For lack of fossils the Devonian/Carboniferous boundary is not clearly defined; instead a lithologic boundary was used. Special stress has been laid upon sedimentary structures.  相似文献