Sedimentation in Lake Biel,an eutrophic,hard-water lake in northwestern Switzerland   总被引：1，自引：0，他引：1  

Dr. Richard F. Wright  Prof. Albert Matter  Marc Schweingruber  Ulrich Siegenthaler 《Aquatic Sciences - Research Across Boundaries》1980,42(2):101-126

A 2-year study of sedimentation in Lake Biel reveals that three major factors can account for the spatial and temporal patterns of tripton sedimentation. Allochthonous inputs of particulate matter mostly derived from the Aare river during spring snowmelt and other high-water periods, provide about 50% of the carbonate and 50% of the siliceous matter collected in sediment traps. Phytoplankton activity in this eutrophic, hard-water lake accounts for the rest of the carbonate and siliceous matter, the latter being mostly diatom frustules. Sedimentation rates are thus highest during periods of maximum river flooding, maximum phytoplankton activity and following the breakdown of the thermocline, at which time trapped particles settle out. Resuspension of sediment is important in at least one basin. Resolution of carbonate appears to be minor.  相似文献   

The isotopic composition of strontium and oxygen in lavas from St. Helena,South Atlantic     

Norman K. Grant  James L. Powell  Flora R. Burkholder  John V. Walther  Max L. Coleman 《Earth and Planetary Science Letters》1976,31(2):209-223

Strontium and oxygen isotope measurements on the alkali basalt-trachyte-phonolite suite of St. Helena show that some of the late-fractionated rocks are enriched in ⁸⁷Sr and depleted in ¹⁸O relative to the older basalts. The data rule out both the formation of the late-fractionated rocks by the partial melting of hydrothermally altered oceanic crust and the contamination of the volcanic rocks by oceanic sediment. It also appears to be incompatible with models based either on the melting of previously fractionated and crystallized liquids in the volcanic pile, or the long-term fractionation of lavas over several millions of years in a sub-volcanic magma chamber.It is concluded that hydrothermal interaction with meteoric water is the most important cause of the ¹⁸O depletion. If the interaction occurred at widely differing temperatures, and involved meteoric and seawaters, it might conceivably have caused both the oxygen and strontium isotope heterogeneities.  相似文献   

Interprét ation des graphiques de relation entre deux éléments chimiques en solution dans l'eau souterraine     

Marc Schoeller 《Journal of Hydrology》1976,28(1):45-52

The relationship line between two chemical constituents dissolved in groundwater does not always begin at the graph origin, but at a fixed coordinates point. This allows the separation between rain water, infiltrating water and groundwater. Besides, this relationship line is not always linear. Equations are given for the curvilinear case.  相似文献   

Untersuchungen über die Eignung des „Kolloidtitrationsverfahrens”︁ von KAWAMURA und TANAKA zur Ermittlung der Ladung kolloidaler und makromolekularer Wasserinhaltsstoffe     

H.-J. Walther  D. Knaack 《洁净——土壤、空气、水》1974,2(6):471-498

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Using archaeological data and sediment parameters to review the formation of the Gravettian layers at Krems-Wachtberg     

Marc Händel  Roswitha Thomas  Tobias Sprafke  Philipp Schulte  Michael Brandl  Ulrich Simon  Thomas Einwögerer 《第四纪科学杂志》2021,36(8):1397-1413

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Die tektonische Natur vonarthrophycus- undspirophyton-ähnlichen Gebilden im Altpaläozoikum der Provinz Buenos Aires (Argentinien)     

Schiller  Walther 《International Journal of Earth Sciences》1930,21(3):145-151

Ohne Zusammenfassung  相似文献   

Intracluster light and the extended stellar envelopes of cD galaxies: an analytical description     

Marc S. Seigar †  Alister W. Graham  Helmut Jerjen 《Monthly notices of the Royal Astronomical Society》2007,378(4):1575-1588

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The SAURON project – IX. A kinematic classification for early-type galaxies     

Eric Emsellem  Michele Cappellari  Davor Krajnovi&#;  Glenn van de Ven  R. Bacon  M. Bureau  Roger L. Davies  P. T. de Zeeuw  Jesús Falcón-Barroso  Harald Kuntschner  Richard McDermid  Reynier F. Peletier  Marc Sarzi 《Monthly notices of the Royal Astronomical Society》2007,379(2):401-417

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The vulnerability of Pyrenean ski resorts to climate-induced changes in the snowpack     

Marc Pons  Juan Ignacio López-Moreno  Martí Rosas-Casals  Èric Jover 《Climatic change》2015,131(4):591-605

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Macroalgal survival in ballast water tanks   总被引：1，自引：0，他引：1  

Flagella MM  Verlaque M  Soria A  Buia MC 《Marine pollution bulletin》2007,54(9):1395-1401

Despite a large amount of research into invasive species and their introductions, there have been no studies focused on macroalgal transport in ballast water. To address this, we collected replicate samples of ballast water from 12 ships in two Mediterranean harbours (Naples and Salerno). Filtered samples were kept in culture for a month at Mediterranean mean conditions (18 degrees C, 12:12h LD, 60micromol photons m(-2)s(-1)). Fifteen macroalgal taxa were cultured and differed according to the geographic origin of the ballast water. Most of the cultured algae were widely distributed species (e.g. Ulva spp. and Acinetospora-phase). However, Ulva ohnoi Hiraoka and Shimada, described from Japan, was hitherto unknown in the Mediterranean Sea. We show for the first time that ballast water can be an important vector for the transport of microscopic stages of macroalgae and that this can be a vector for the introduction of alien species.  相似文献