Paleolimnological evidence for the recent acidification of Llyn Hir,Dyfed, Wales     

S. C. Fritz  A. C. Stevenson  S. T. Patrick  P. G. Appleby  F. Oldfield  B. Rippey  J. Natkanski  R. W. Battarbee 《Journal of Paleolimnology》1989,2(4):245-262

A variety of paleolimnological techniques, coupled with historical data on land-use and fisheries, are used to evaluate the magnitude, timing, and causes of acidification of Llyn Hir, a moorland lake in central Wales. pH reconstruction based on diatom analysis suggests a gradual decline in lakewater pH beginning ca. 1870 and intensifying in the mid-1930's, with a total decline of 1.1 pH units between 1870 and 1984. This pH decline correlates with increased sedimentary concentrations of carbonaceous particles, trace metals, and magnetic minerals, which indicate the local deposition of atmospherically transported products of fossil-fuel combustion. Pollen data and the historical record show no significant alterations in land-use or catchment vegetation, indicating that acidification of Llyn Hir is a result of the increased deposition of atmospheric pollutants, not of land-use and vegetation change.Limnological Research Center Contribution No. 374.  相似文献   

Solution of an n-layer problem by a seismic reflection method     

Fritz Gassmann 《Geophysical Journal International》1961,4(S0):151-157

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Mesozoic (Lower Jurassic) red stromatactis limestones from the Southern Alps (Arzo, Switzerland): calcite mineral authigenesis and syneresis-type deformation     

Fritz Neuweiler  Daniel Bernoulli 《International Journal of Earth Sciences》2005,94(1):130-146

The Broccatello lithological unit (Lower Jurassic, Hettangian to lower parts of Upper Sinemurian) near the village of Arzo (southern Alps, southern Switzerland) is a mound-shaped carbonate deposit that contains patches of red stromatactis limestone. Within the largely bioclastic Broccatello unit, the stromatactis limestone is distinguished by its early-diagenetic cavity system, a relatively fine-grained texture, and an in-situ assemblage of calcified siliceous sponges (various demosponges and hexactinellids). A complex shallow subsurface diagenetic pathway can be reconstructed from sediment petrography in combination with comparative geochemical analysis (carbon and oxygen isotopes; trace and rare earth elements, REE + Y). This pathway includes organic matter transformation, aragonite and skeletal opal dissolution, patchy calcification and lithification, sediment shrinkage, sagging and collapse, partial REE remobilization, and multiple sediment infiltration. These processes occurred under normal-marine, essentially oxic conditions and were independent from local, recurring syn-sedimentary faulting. It is concluded that the stromatactis results from a combination of calcite mineral authigenesis and syneresis-type deformation. The natural stromatactis phenomenon may thus be best explained by maturation processes of particulate polymer gels expected to form in fine-grained carbonate sediments in the shallow subsurface. Conditions favorable for the evolution of stromatactis appear to be particularly frequent during drowning of tropical or subtropical carbonate platforms.

Daniel BernoulliEmail:

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In Memoriam: John Platt Bradbury (1936–2005)     

Walter?DeanEmail author  Sheri?Fritz  Cathy?Whitlock  William?Watts 《Journal of Paleolimnology》2005,34(4):iii-iv

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Die variskischen Züge im Faltenbilde des nördlichen Harzvorlandes zwischen Braunschweig und Hildesheim     

Fritz Groebel 《International Journal of Earth Sciences》1926,17(4):275-280

Ohne Zusammenfassung  相似文献   

Zur Entwicklung der afrikanischen Stromsysteme     

Fritz Haas  Ernst Schwarz 《International Journal of Earth Sciences》1913,4(8):603-607

Ohne Zusammenfassung  相似文献   

Der Präsident der Notgemeinschaft der Deutschen Wissenschaft,Staatsminister Dr. Schmidt-Ott,als Förderer der Deutschen Atlantischen Expedition 1925–1927     

Fritz Spiess 《Ocean Dynamics》1950,3(1-2):6-9

Ohne Zusammenfassung  相似文献   

Über die mittlere Intensität von starken erdmagnetischen Stürmen in Abhängigkeit von der geomagnetischen Breite     

Fritz Errulat 《Ocean Dynamics》1948,1(2-3):72-79

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Bemerkungen zur Karte der Mißweisung 1945.5 im südlichen Teil der Nord-und Ostsee     

Fritz Errulat 《Ocean Dynamics》1948,1(5-6):176-177

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Ozone measurements during sudden ionospheric disturbances     

Sigmund Fritz 《Meteorology and Atmospheric Physics》1951,4(1):343-350

Summary In order to investigate the effect of increased solar ultraviolet radiation on total atmospheric ozone, ozone observations have been made during sudden ionospheric disturbances (S. I. D.). If one can assume that the ratio of the extraterrestrial intensity of sunlight at 3110 Å to that at 3300 Å (the wavelengths observed by the measuring instrument) remains unchanged during days with S. I. D., it is found that ozone changes associated with S. I. D. s are small or absent, in agreement with qualitative theoretical expectation.

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Zusammenfassung Um die Auswirkung einer Zunahme der ultravioletten Sonnenstrahlung auf das atmosphärische Ozon zu untersuchen, wurden beim Auftreten desMögel-Dellinger-Effekts (Sudden Ionospheric Disturbances, S. I. D.) Ozonmessungen angestellt. Unter der Annahme, daß an den Tagen mit S. I. D. das Verhältnis der Intensität der extraterrestrischen Sonnenstrahlung bei 3110 Å zu der bei 3300 Å konstant bleibt, findet man, daß die gleichzeitigen Ozonänderungen entweder sehr klein sind oder ganz fehlen, was in Übereinstimmung mit dem theoretisch zu erwartenden Verhalten ist.

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Résumé Pour examiner l'effet de croissance de la radiation solaire ultraviolette sur l'ozone total atmosphérique, des mesures de l'ozone ont été faites pendant certains jours avec des perturbations ionosphériques brusques (Sudden Ionospheric Disturbances, S. I. D.) qui apparaissent ordinairement simultanément avec une éruption solaire. Si l'on suppose que le quotient de l'intensité extra-terrestre du rayonnement solaire pour -3110 Å à celle pour =3300 Å est constant, on constate que les variations de l'ozone coïncidentes avec les S. I. D. sont petites ou manquent complètement ce qui est en bon accord qualitatif avec la théorie.

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With 4 Figures.  相似文献