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401.
Summary Diabase dikes which cut across the pre-Alpine metamorphic complex (Altkristallin) of the Stubai-Ötztal-Alps show a highly variable composition in the basalt-andesite field. The primary magmatic minerals were converted into metamorphic assemblages during Alpine regional metamorphism that increased in grade systematically from northwest to southeast. Six mappable mineral parageneses in the diabase dikes demonstrate temperature ranges from 300° in the northwesternmost outcrops to 530° in the southeastern Ötztal Alps.
With 9 Figures
This work has been supported by the Österreichischer Fonds zur Förderung der wissenschaftlichen Forschung (Forschungsschwerpunkt S15). 相似文献
Alpidische Metamorphose von Diabasgängen im Ötztal-Stubaier Altkristallin
Zusammenfassung Die Diabasgänge im Ötztal-Stubaier Altkristallin durchschlagen diskordant die präalpidischen Strukturen. Die einzelnen Gänge zeigen untereinander einen stark schwankenden Chemismus basaltischer-andesitischer Zusammensetzung.Der primäre magmatische Mineralbestand ist durch eine von SE nach NW abnehmende alpidische Metamorphose vollständig umgewandelt. Die dabei gebildeten Minerale lassen sich in sechs verschiedene, kartierbare Paragenesen gliedern, die einer Temperaturzunhame von ca. 300° auf 530° entsprechen.
With 9 Figures
This work has been supported by the Österreichischer Fonds zur Förderung der wissenschaftlichen Forschung (Forschungsschwerpunkt S15). 相似文献
402.
Toxicological and ecotoxicological assessment of water tracers 总被引:2,自引:3,他引:2
H. Behrens U. Beims H. Dieter G. Dietze T. Eikmann T. Grummt H. Hanisch H. Henseling W. Käß H. Kerndorff C. Leibundgut U. Müller-Wegener I. Rönnefahrt B. Scharenberg R. Schleyer W. Schloz F. Tilkes 《Hydrogeology Journal》2001,9(3):321-325
Uncertainties regarding possible negative effects on the environment or on human health of authorizing tracing experiments
in groundwater and surface waters led to the establishment of a Working Group at the German Federal Environmental Agency (Umweltbundesamt
– UBA) for conducting a toxicological and ecotoxicological assessment. A total of 17 water tracers was assessed by the Working
Group on the basis of the results of toxicological tests, the available literature, and the group's expert knowledge. In the
future, tracers that pose a risk to the environment or to human health should no longer be used. Nevertheless, there are a
number of tracers that could be used in hydrogeological and hydrological investigations for water-pollution-control purposes
with no adverse environmental impact.
Electronic Publication 相似文献
403.
New information obtained about >500 keV electron intensity enhancements, which have been observed intermittently close to the outer edge of the electron radiation belt, is used in conjunction with an earlier statistical study by Brown and Stone (1972) to investigate processes which could lead to such structures. The enhancements are typically of ~20 sec duration and occur in a very narrow invariant latitude band, maximally 2° wide. The intensity increase relative to the “normal” background level is up to a factor 10, and the “spike” frequency of occurrence is strongly local time dependent, with more spikes observed in the night and dusk-noon sectors than in the noon-dawn sector. The processes investigated quantitatively are distortions of the magnetospheric topology in the equatorial region, wave-particle interactions and the effects of ionospheric currents. It is shown that the various processes which contribute to equatorial field disturbances can explain the observations. 相似文献
404.
Zusammenfassung Die vorliegende Arbeit behandelt die Ergebnisse von Messflügen zur Bestimmung der Konzentrationsverteilung von Spurengasen in der freien Atmosphäre. Auf Grund dieser Aufstiege war es erstmals möglich, den Gehalt der Atmosphäre an Schwefeldioxyd und Stickstoffdioxyd bis in Höhen von 6000 m zu erfassen. Die gewonnene mittelere Konzentrations-verteilung bietet die Basis zu Abschätzungen über den Haushalt und die mittlere Verweilzeit von SO2 und NO2 in der Troposphäre.
Summary This paper deals with the results of aircraft ascents for the measurement of the vertical distribution of atmospheric trace gases in the free atmosphere. The aircraft ascents permitted for the first time to measure the SO2- and NO2-concentration up to 6000 m. On the basis of the average distribution assumptions on the tropospheric budget of SO2 and NO2 as well as on the average tropospheric residence time of these gases were made.相似文献
405.
Michael Owor Tina Hartwig Andrew Muwanga Dieter Zachmann Walter Pohl 《Environmental Geology》2007,51(6):1065-1075
The abandoned Kilembe copper mine in western Uganda is a source of contaminants, mobilised from mine tailings into R. Rukoki
flowing through a belt of wetlands into Lake George. Water and sediments were investigated on the lakeshore and the lakebed.
Metal associations in the sediments reflect the Kilembe sulphide mineralisation. Enrichment of metals was compared between
lakebed sediments, both for wet and dry seasons. Total C in a lakebed core shows a general increment, while Cu and Co decrease
with depth. The contaminants are predominant (> 65%) in the ≤ 63 μm sediment size range with elevated Cu and Zn (> 28%), while
Ni, Pb and Co are low (< 18%) in all the fractions. Sequential extraction of Fe for lakeshore sediment samples reveals low
Fe mobility. Relatively higher mobility and biological availability is seen for Co, Cu and S. Heavy metal contents in lake
waters are not an immediate risk to the aquatic environment. 相似文献
406.
Jens Mingram Jörg F. W. Negendank Achim Brauer Dieter Berger Andreas Hendrich Michael Köhler Hartmut Usinger 《Journal of Paleolimnology》2007,37(4):517-528
We present a unique, versatile piston corer for recovering continuous lake and bog sediment sequences with superior accuracy
and quality. The main components of the system and their function are described, with special focus on measures for obtaining
long, continuous lake sediment sections up to a current maximum length of 95 m. Examples of lake sediment profiles obtained
with this system from different climatic zones are presented. 相似文献
407.
The breach in the dam of a tailing pond in the processing plant of a gold mine in Baia Mare (NW Romania) in January 2000 lead to an ecological disaster in the rivers Szamos and Tisza. It was mainly caused by the released slurries containing cyanides and heavy metals. The investigation of surface sediment samples and depth profiles of the years 2000 and 2001 documented the pollution of the rivers Szamos and Tisza on Hungarian territory. In the Szamos and large areas of the Tisza floodplains a significant enrichment with the heavy metals Pb, Cd, Cu, and Zn is existent. The identification of the binding forms with sequential extraction showed that Cd and Zn exist in an easily available form. Therefore the remobilization is possible and an environmental hazard in the downstream areas must be considered. The anthropogenically caused portions of heavy metal concentrations decrease considerably with increasing distance to the mining region. The comparison of the concentrations of heavy metals in both years shows that the pollution is not only caused by the accident in January 2000. The increase of concentrations is based on the permanent input of pollutants into the rivers. The pollution is mainly caused by the erosion of exposed tailing dumps and the poor maintenance of the treatment plants. 相似文献
408.
With the Water Framework Directive (WFD) the European Commission (EC) is requested to define environmental quality standards for pollutants to protect aquatic life in surface waters. Quality standards have to be derived by a scientific risk assessment and should not be exceeded. The recommended quality standards are mainly based on long term toxicological tests with algae, crustaceans and fish. The lowest effect concentration is divided by an assessment factor between 10 and 1000, which considers the data quality and quantity. In this work funded by the German Länder Working Party on Water (Länderarbeitsgemeinschaft Wasser – LAWA) environmental quality standards for 40 considered relevant substances were derived for aquatic ecosystems. The data sheets cover the identification of the compounds, their behaviour in the environment (physical‐chemical properties, biotic and abiotic degradation, sorption, bioaccumulation), information about mode of action, uses, analytical determination and available quality criteria. Ecotoxicological effect concentrations for bacteria, algae, protozoa, aquatic plants, crustaceans, fish, amphibians, insects and molluscs are listed. For 17 of the 40 hazardous substances investigated, quality objectives above 1 μg/L were derived. For 12 substances the values were between 0.1 μg/L and 1 μg/L and for 5 substances lower than 0.1 μg/L. Incomplete ecotoxicological data sets of the remaining compounds do not allow the derivation of quality standards. Especially for drugs further ecotoxicological test results are needed. 相似文献
409.
Sibyll Schaphoff Wolfgang Lucht Dieter Gerten Stephen Sitch Wolfgang Cramer I. Colin Prentice 《Climatic change》2006,74(1-3):97-122
This study investigates commonalities and differences in projected land biosphere carbon storage among climate change projections derived from one emission scenario by five different general circulation models (GCMs). Carbon storage is studied using a global biogeochemical process model of vegetation and soil that includes dynamic treatment of changes in vegetation composition, a recently enhanced version of the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM). Uncertainty in future terrestrial carbon storage due to differences in the climate projections is large. Changes by the end of the century range from −106 to +201 PgC, thus, even the sign of the response whether source or sink, is uncertain. Three out of five climate projections produce a land carbon source by the year 2100, one is approximately neutral and one a sink. A regional breakdown shows some robust qualitative features. Large areas of the boreal forest are shown as a future CO2 source, while a sink appears in the arctic. The sign of the response in tropical and sub-tropical ecosystems differs among models, due to the large variations in simulated precipitation patterns. The largest uncertainty is in the response of tropical rainforests of South America and Central Africa. 相似文献
410.
During routine analysis of running water samples differences of the analytical results of water‐soluble anions were observed between analysis carried out immediately after sampling and after storage of the cooled/frozen sample. This phenomenon was investigated for some years with the “model ion” chloride. A high number of samples (ca. 210) were analysed over three years with different analytical methods, and by alteration of the sample containers the discrete physical influence of the wall effect of the sample vessel could be worked out definitely. No significant differences occur with the mean value of the year but the single values have high differences in the positive or negative direction. Assuming a similar behaviour of other water constituents when preserved by freezing the analytical values had to be looked at very critically. 相似文献