MELIMEX,an experimental heavy metal pollution study: Effects of increased heavy metal load on crustacea plankton     

Jacques Urech 《Aquatic Sciences - Research Across Boundaries》1979,41(2):247-260

The crustacea plankton of three artificial model lakes in Lake Baldegg was observed during 15 months. Two were loaded continuously with low concentrations of five heavy metals (Hg, Cu, Cd, Zn, Pb). It was attempted to explain the significant lower abundances of the loaded limno-corrals. The results suggest that the decrease was not, or only partially, caused by the lower food supply in the loaded limnocorrals, but directly by the heavy metals. Accompaning laboratory tests show significantly increased egg-development-times for two species of those animals from the loaded limno-corrals. Two other species show a decrease of the egg production/♀. It cannot be determined if increased mortality of particular animal stages was caused by heavy metals.

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Résumé On a observé pendant 15 mois les crustacés planctoniques des trois modèles de lac installés dans le lac de Baldegg. Dans deux de ceux-ci, une charge constante de cinq métaux lourds (Hg, Cu, Cd, Zn, Pb) de faible concentration a été maintenue. On a essayé d'expliquer la faible concentration significative de plancton dans les bassins limnologiques chargés. Les résultats montrent que la diminution n'était que partiellement ou pas du tout causée par le faible approvisionnement en nourriture dans les bassins chargés, mais directement par les métaux lourds. Les tests de laboratoire montrent significativement l'augmentation du temps de développement des œufs pour deux espèces animales des bassins chargés. Deux autres espèces montrent une diminution de la production d'œufs/♀. On ne peut pas déterminer l'augmentation de la mortalité des animaux causée par les métaux lourds à des stades particuliers de développement.

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Copper,zinc and lead minerals suspended in ocean waters     

Jacques Jedwab 《Geochimica et cosmochimica acta》1979,43(1):101-110

Individual particles of malachite, tenorite, paratenorite, laurionite and sphalerite, as well as several intermediate compounds of Cu, Zn, Pb, Cl, S, OH and CO₃ have been identified among paniculate matter filtered from Atlantic and Pacific deep water samples. These particulate matter samples were provided mainly by the GEOSECS 1972 and 1974 cruises. The detection and the identification of the individual heavy metal compounds were made by a combination of light microscopy, SEM, EMP and XRD. The highest frequency of heavy metal compounds has been found at several North Atlantic, and at one Antarctic stations. Their origin can, at least partly, be ascribed to technological influences, since metallic copper and brass particles are sometimes found associated with, or included in the heavy metal compounds. Others, however, result clearly from growth in the water.  相似文献   

Sur lesStaurastrum du lac Léman     

Dr Jacques Naef  Prof. Dr Pierre Bourrelly  Paul Martin  Denis Mack 《Aquatic Sciences - Research Across Boundaries》1978,40(1):51-59

Among the Desmids which have been observed in the plankton of the lake of Geneva, organisms having 4 processes have been discovered. Their frequency in the water samples and the results of in vitro studies on their progeny when cultivated in several environmental conditions, allow us to consider these organisms as a form ofStaurastrum sebaldi. The triradiate organisms have been incorrectly named and one must now consider three different species.   相似文献   

Garnet—biotite gneiss in ‘Système du Graphite’ (Madagascar): Petrology and fluid inclusions     

Liliane Berglund  Jacques Touret 《Lithos》1976,9(2):139-148

Primary ‘carbonic’ fluid inclusions filled with nearly pure high density CO₂ occur in garnet in a garnet—biotite gneiss from ‘Système du Graphite’, Komajia, Madagascar (Malagasy). They have been formed during syntectonic growth of the garnet under granulite facies conditions. Most of the biotite appears to have crystallized later than the garnet under the influence of more water rich fluids.  相似文献   

The Amsterdam-St. Paul volcanic province,and the formation of low Al tholeiitic andesites     

Bernard M. Gunn  Norman D. Watkins  Walter E. Trzcienski  Jacques Nougier 《Lithos》1975,8(2):137-149

The island of St. Paul in the Indian Ocean is located on the axis of the southeastern branch of the Indian Ocean Rise, as is the similar volcano of Amsterdam, 80 km to the north. Both volcanoes and possibly part of the local ridge are formed of a high-alumina plagioclase tholeiite making this a distinctive volcanic province. Lavas with Al₂O₂ contents of 12 to 22% are directly related by plagioclase fractionation. Residual rocks are a distinctive low silica, low alumina, potassic andesite with andesine and even olligoclase feldspar. Parallel lines of evolution exist in the sea floor plagioclase tholeiites, which differ only in slightly lower tenor of Sr and potassium group elements, and in the Steens Mountain tholeiites of Oregon, which differ in their significantly higher Sr and K group elements  相似文献   

The subalkaline potassic magmatism of the Ballons massif (Southern Vosges,France): shoshonitic affinity     

Maurice Pagel  Jacques Leterrier 《Lithos》1980,13(1):1-10

A systematic geochemical study of the Ballons plutonic complex (Southern Vosges, France) indicates that the border facies of the massif are composed of two continuous differentiation series ranging from gabbros to quartz monzonites and very similar to the shoshonitic associations (high K₂O/Na₂O ratios as well as high Ba, Sr, U and Th contents). The existence of a geochemical discontinuity between the two series and the monzogranite, which is the principal component of the massif, argues against the monzogranite being directly related to the two differentiation series by fractional crystallization. The zoned structure of the monzogranite can be attributed to in situ crystal fractionation.  相似文献   

Surface features associated with transform faults: A comparison between observed examples and an experimental model     

Vincent Courtillot  Paul Tapponnier  Jacques Varet   《Tectonophysics》1974,24(4):317-329

In several tectonic provinces where active ridge segments are offset, transform faults are expected but not observed. This paper discusses the evolution of the surface expression of some transform faults with the help of a few geological examples and a simple experimental clay model in which the importance of en-échelon fault systems is assessed. We conclude that the azimuth of observed fault traces may not coincide with the direction of movement, but be oblique to it. Thus we must be cautious when using a fieldobserved fault direction to infer a transform-fault direction for use in plate-tectonics models. This study also suggests the scale at which the assumption of rigid plates fails.  相似文献   

Determination des echanges verticaux moyens dans la couche limite planetaire a partir des donnees statistiques obtenues par les radiosondages de temperature     

Daniel Guedalia  Aimé Druilhet  Jacques Fontan 《Boundary-Layer Meteorology》1974,7(4):457-473

We have studied the vertical structure of the planetary boundary layer (PBL) as well as the vertical exchanges between this layer and the free atmosphere, using average macroscopic temperature data obtained from radiosondes. For this study we have used, for seven months in 1972, twice-daily radiosondes (00 and 12 H) from Trappes (Paris area) and PointK (Atlantic Ocean). The vertical structure of the PBL is given in the first part of the present work in terms of monthly average statistical parameters (vertical temperature gradient, frequency and level of inversion layers, frequency and thickness of mixing layers). We have thus demonstrated for the continental station, the influence of the daily cycle on the vertical temperature gradient; we have determined the monthlyH _M level above which the daily variation is not noticed. However, for the oceanic station, the absence of a daily cycle makes the temperature gradients at 00 and 12 H identical. The study of temperature inversion layers clearly indicates a high probability of their existence between 1500 and 2000 m; this probability is more than 80% both in summer at PointK, and in winter at Trappes. Similarly, we have demonstrated the annual evolution of the level of these elevated inversions at the two stations. An identical process has been performed in the case of the mixing layers. In the second part of our study, we have used a relationship between the vertical temperature gradient and the coefficients of matter exchange (K _z ), obtained from natural radioactive tracers (Guedaliaet al., 1974). Statistics have thus been obtained on the values ofK _z in the various layers above the two stations. These statistics prove that for the two stations and above 1500 m, values of the coefficients between 1 and 5 m² s^?1 are the most frequent; on the other hand, below 1500 m, the distribution of the coefficientsK _z offers different characteristics according to the month and to the station considered. Finally, we have used the concept of ‘equivalent coefficient’ -K _e - to characterize the exchanges between two levels considered as a whole. We have made a comparison of the values ofK _e when in the 0–1000 m layer and when in the 0–2000 m layer. The equivalent coefficientK _e allows us to compare the average exchanges above the two areas; thus, in summer, between the 0 and 1000 m level, the exchanges are more important above Trappes than they are above Point K. On the other hand, whatever may be the vertical structure of the PBL below, the value ofK _e in the 0–2000 m-layer is always between 1 and 5 m² s^?1. A generalisation of such a study applied to better chosen continental and oceanic sites would allow a comprehensive view of the structure of the PBL as well as of the turbulent exchanges between the PBL and the free atmosphere.  相似文献   

Reduction of surface gravity data from global atmospheric pressure loading   总被引：4，自引：0，他引：4  

Jean-Paul Boy  Pascal Gegout  Jacques Hinderer 《Geophysical Journal International》2002,149(2):534-545

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Inversion of earthquake focal mechanisms to obtain the seismotectonic stress IV—a new method free of choice among nodal planes     

Jacques Angelier 《Geophysical Journal International》2002,150(3):588-609

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