Provenance of the Bosnian Flysch

Sandwiched between the Adriatic Carbonate Platform and the Dinaride Ophiolite Zone, the Bosnian Flysch forms a c. 3000 m thick, intensely folded stack of Upper Jurassic to Cretaceous mixed carbonate and siliciclastic sediments in the Dinarides. New petrographic, heavy mineral, zircon U/Pb and fission-track data as well as biostratigraphic evidence allow us to reconstruct the palaeogeology of the source areas of the Bosnian Flysch basin in late Mesozoic times. Middle Jurassic intraoceanic subduction of the Neotethys was shortly followed by exhumation of the overriding oceanic plate. Trench sedimentation was controlled by a dual sediment supply from the sub-ophiolitic high-grade metamorphic soles and from the distal continental margin of the Adriatic plate. Following obduction onto Adria, from the Jurassic–Cretaceous transition onwards a vast clastic wedge (Vranduk Formation) was developed in front of the leading edge, fed by continental basement units of Adria that experienced Early Cretaceous synsedimentary cooling, by the overlying ophiolitic thrust sheets and by redeposited elements of coeval Urgonian facies reefs grown on the thrust wedge complex. Following mid-Cretaceous deformation and thermal overprint of the Vranduk Formation, the depozone migrated further towards SW and received increasing amounts of redeposited carbonate detritus released from the Adriatic Carbonate Platform margin (Ugar Formation). Subordinate siliciclastic source components indicate changing source rocks on the upper plate, with ophiolites becoming subordinate. The zone of the continental basement previously affected by the Late Jurassic–Early Cretaceous thermal imprint has been removed; instead, the basement mostly supplied detritus with a wide range of pre-Jurassic cooling ages. However, a c. 80 Ma, largely synsedimentary cooling event is also recorded by the Ugar Formation, that contrasts the predominantly Early Cretaceous cooling of the Adriatic basement and suggests, at least locally, a fast exhumation.     

Understanding Perturbation on the Simplex: A Simple Method to Better Visualize and Interpret Compositional Data in Ternary Diagrams

Perturbation is an operation defined on the simplex and can be used for centering compositional data in a ternary diagram, applying objective criteria. Because a straight line in the original diagram is still astraight line in the perturbed diagram, gridlines or compositional fields defined by straight lines can easily be included in the operation. Simultaneous perturbation of data, gridlines, and/or compositional fields is shown to improve both visualization and graphical interpretation of compositions in ternary diagrams. This is illustrated by some examples using simulated as well as real data.     

Application of participatory principles to investigation of the natural world: An example from Chile

Participatory research in environmental and natural resources-related fields is premised on many of the same notions that underlie participatory processes in decision making. This study examines one instance of participatory research to assess the extent to which the documented benefits of participatory decision-making hold up in the context of research. A survey of Chilean shell-fishers engaged in research with marine biologists assesses the relationships between four variables: fishers’ participation in research, fishers’ opinions of biologists, fishers’ trust in biologists, and fishers’ acquisition of knowledge from biologists. Results illuminate the multidimensionality of these variables and suggest that complex interrelationships between them make the benefits of participatory research more nuanced than those reported for participatory decision-making. For instance, participatory research may provide low benefits when participatory research outcomes differ little from those produced solely by scientists. In addition, high-cost scenarios may result when outcomes of participatory research are inferior to those produced solely by scientists. A third downside may result when participation leads participants to increase their deference to scientific knowledge, thereby defeating the corroborative purpose of their participation. A fourth effect may occur when increased trust by in scientists results from participation, decreasing participants’ perceived need to take part in research.     

On the effect of emissions from aircraft engines on the state of the atmosphere

Emissions from aircraft engines include carbon dioxide, water vapour, nitrogen oxides, sulphur components and various other gases and particles. Such emissions from high-flying global civil subsonic air traffic may cause anthropogenic climate changes by an increase of ozone and cloudiness in the upper troposphere, and by an enhanced greenhouse effect. The absolute emissions by air traffic are small (a few percent of the total) compared to surface emissions. However, the greenhouse effect of emitted water and of nitrogen oxides at cruise altitude is potentially large compared to that of the same emissions near the earth’s surface because of relatively large residence times at flight altitudes, low background concentrations, low temperature, and large radiative efficiency. Model computations indicate that emission of nitrogen oxides has doubled the background concentration in the upper troposphere between 40○N and 60○N. Models also indicate that this causes an increase of ozone by about 5-20%. Regionally, the observed annual mean change in cloudiness is 0.4%. It is estimated that the resultant greenhouse effect of changes in ozone and thin cirrus cloud cover causes a climatic surface temperature change of 0.01-0.1 K. These temperature changes are small compared to the natural variability. Recent research indicates that the emissions at cruise altitude may increase the amount of stratospheric aerosols and polar stratospheric clouds and thereby have an impact on the atmospheric environment. Air traffic is increasing about 5-6% per year, fuel consumption by about 3%, hence the effects of the related emissions are expected to grow. This paper surveys the state of knowledge and describes several results from recent and ongoing research.     

Attenuation models inferred from intraplate earthquake recordings

Strong-motion recordings at 87 sites from 56 different intraplate earthquakes from North America, Europe, China and Australia have been used through a two-step regression analysis to develop new attenuation models for peak ground acceleration, and for pseudo-relative velocity for frequencies of 0.25, 0.5, 1.0, 2.0, 5.0 and 10.0 Hz, all for 5 per cent of critical damping. The estimates are obtained along with an analysis of residuals and scatter. A similar regression analysis has been performed also for Fourier spectra of acceleration, in which case the coefficient for the anelastic term has been interpreted in terms of a frequency dependent quality factor Q. The resulting Q-model shows a strong frequency sensitivity with values around 600–700 at 1 Hz, around 2000 at 10 Hz and around 5200 at 25 Hz. These PGA, PSV and Q results depend, however, on the underlying assumption for geometrical spreading, in particular for low frequencies.     

Anreicherung von Metallionen durch Membranfiltration von Polyelektrolytkomplexen

The separation of heavy metals by complexation with macromolecular water-soluble agents and subsequent ultrafiltration is described. The method can be expected to join common techniques of metal separation like liquid-liquid extraction, adsorption, redox reaction or liquid membrane permeation. Reactions between metal ions and polymer phases are characterized as pH-dependent distribution equilibria illustrated at a propene-maleic acid copolymer as an example. The complexation behaviour of the substance under study is governed by isotherms of the saturation type. Attempts proved to be successful to calculate break-through constants as well as saturation capacities from batch-type studies and dynamic measurements by transferring the laws of adsorption and ion exchange, respectively, to the ultrafiltration process. The quantities of fixed metals amounting to about 2.5 mmol/g were found to be in the range of moderate adsorbents. A solution consisting of 3 solutes has been tested to get more detailed information on mixture behaviour as compared to single component systems. In the long run, the proposed method should provide an additional variant for the extraction and concentration of metal ions from diluted aqueous solutions.     

Über die bevorzugte kristallographische orientierung der einzelkristalle in natürlichen faserhalitaggregaten

Zusammenfassung Die Orientierung der Kristallite eines Faserhalites wurde mit einer Röntgen-U-Tisch-Methode bestimmt, indem für jedes Korn die drei Symmetrieachsen des durch einen Bildverstärker sichtbar gemachten Laue-Bildes zentral gestellt wurden. Die Darstellung der Ergebnisse erfolgte in einer flächentreuen Projektion durch Eintragung der Pole der Kornschnittflächen im entsprechenden Präparat in einem sphärischen Dreieck mit den Durchstoßpunkten der Senkrechten auf (001), (011) und (111) als Eckpunkten.Aus der Bearbeitung eines Schnittes senkrecht zur Faserrichtung ergibt sich, daß etwa ein Drittel der Kristallite eine zweizählige Achse nahe zur Faserrichtung hat; das entspricht qualitativ den Erwartungen aus den vektoriellen Wachstumsgeschwindigkeiten beim Halit. Die Ergebnisse aus Schnitten parallel zur Faserachse sind nicht so klar zu interpretieren, jedoch zeigen sich auch hier Orientierungseffekte.

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Preferred crystallographic orientation of crystallites in natural fibrous halite aggregates

Summary The orientations of the crystallites in a fibrous halite were determined using an X-ray universal stage method in which for each individual grain the Laue-diagrams of the three symmetry axes, made visible by an image intensifier, were set at the center. The results are presented in an equal-area net using the poles of the corresponding grain's sections in a spherical triangle with the normals to (001), (011) and (111) as corner points.Studies on a thin section perpendicular to the fiber direction revealed a two-fold axis approximately along the fiber direction for about a third of the crystallites. This is qualitatively what is expected from halite vectorial growth rates. The results of sections parallel to the fiber axis are not so clear but do show orientation effects.

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