Stratigraphische Untersuchungen im Paläozoikum des Montseny (Katalonien/Spanien)

The Catalonian Coast Bange and Inner Bange are the connecting link between the East-Pyrenees in the North and the Celtiberic Chains in the Southeast. During the Paleozoic the Catalonian Ranges differ from both areas by extreme eugeosynclinal conditions with very low rates of sedimentation. Similar conditions in the Hercynian of Spain are to be found in the “pelagic” areas of the southwestern part of the Sierra Morena from upper Ordovician to Lower Carboniferous times. Based on the mapping of the Avencó-Valley (a part of the Montseny-Mountains/Catalonia) the Paleozoic layers are described and a stratigraphic subdivision is worked out. The conformable sequence begins in the upper Ordovician (Caradoc) and continues to the Visean. Buntsandstein is unconformably overlying the Paleozoic. The Ordovician/Silurian boundary is determined by Graptolithes; the Silurian/Devonian boundary is located within a sequence of Orthoceras-limestone as elsewhere in the Catalonian Range. For lack of fossils the Devonian/Carboniferous boundary is not clearly defined; instead a lithologic boundary was used. Special stress has been laid upon sedimentary structures.     

Enhancement of (0k0) reflections of clay minerals in a Guinier camera

In oriented aggregates of flake-like clay minerals the (0k0) planes tend to orient in such a way that their normals become aligned subparallel to the specimen layer. This property may be utilized to obtain enhanced (060) intensities provided that the normal of the clay layer and the primary beam intersect at an angle equal to the Bragg angle for (060). This condition may be satisfied in a Guinier camera.From the degree of orientation t(_00l) of the basal planes the enhancement factor t _(0k0) is calculated according to three models. For t _(00l) between 5 and 50 times the intensity of random orientation the enhancement t _(0k0) varies between 2 and 5.5 times.     

Bergfußflächen und das System der Flächenbildung in den ariden Subtropen und Tropen

Zusammenfassung In den Trockengebieten sind in der Fußregion von Bergen und Gebirgen ausgedehnte Fußflächen entstanden. Sie sind Ausgleichsflächen zwischen den in Abtragung befindlichen höheren Reliefteilen und den tiefer liegenden Vorlandebenen. Zerschnitten oder unzerschnitten haben sie entscheidenden Anteil am gesamten Flächenrelief. Die Tendenz zur Erhaltung älterer Flächenteile prägt das Gesamtbild des Flächenreliefs der ariden Zone. Bereiche der Zerschneidung und solche der Flächenerhaltung schließen sich klimazonal nicht aus. Die Morphogenese aller Fußflächen beginnt mit der ersten syn- bzw. posttektonischen Anlage einer Initialfläche.Fußflächen mit mehreren Niveaus und Terrassen bilden auf morphologisch weichen (wechselharten) Sedimentgesteinen ein Glacis-System, während besonders auf Kristallingestein ausgedehnte Pedimentflächen entstanden sind. Mit zunehmend ariderem Klima sind alle Fußflächen wenig oder nicht mehr zerschnitten. Morphogenetisch sind Glacis und Pedimente gleichartige Bildungen desselben klimatisch-geomorphologischen Systems der ariden Zone, morphographisch zeigen sie Unterschiede.Die ariden Subtropen und Tropen bilden klimatisch-morphologisch ein eigenes morphodynamisches und genetisches System der Flächenbildung auf der Erde.

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In arid regions wide piedmont plains (Fußflächen) have been formed as the glacis of higher mountains. They are compensation levels (Ausgleichsflächen) between higher parts of relief which are at present eroded, and the lower foreland plains. Whether they are dissected or not, they constitute a large part of all plains. The trend to conserve older parts of the relief is reflected in the whole appearance of the arid zone. Regions of erosions and of plain conservation do not exclude each other in the same climatic zone. The morphogenesis of all piedmont plains begins with a first syntectonic or posttectonic disposition towards an Initial plain (Initialfläche).Piedmont plains with various levels and terraces may develop as a glacissystem on alternatively soft and hard sediments, while on crystalline material extensive rock pediments are formed.In a climate becoming more arid, dissection of all piedmont plains decreases. From a morphogenetic point of view, glacis and rock pediments are similar formations of the same climatic-geomorphological system of the arid zone. Only morphographically they show differences.With regard to climatic morphology, the arid subtropics and tropics have their own morphodynamic and genetic system of plain formation.

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Résumé Dans les zones arides, des glacis étendus se sont formés dans les régions de piémont. Ils représentent des « surfaces d'aplanissement » entre les régions élevées du relief et les plaines de piémont en contre-bas. Les glacis, qu'ils soient entaillés ou non, ont une part importante dans le relief des surfaces d'érosion de la zone aride. La tendance à la conservation d'aplanissements anciens est caractéristique dans cette zone dans laquelle l'érosion linéaire et la conservation des glacis d'érosion sont de la même efficacité. La morphogenèse de tous les glacis dérive d'une « surface initiale » syntectonique ou post-tectonique, qui est la surface de départ.Les glacis sur roches sédimentaires (peu résistantes ou tendres) présentent une morphologie typique comportant plusieurs niveaux de glacis et terrasses (système de glacis). Dans le domaine des roches résistentes et moins hétérogènes, surtout sur roche cristalline, dominent souvent des surfaces pédimentaire étendues et moins inclinées. Les glacis et les pédiments sont de moins en moins entaillés en fonction de l'aridité croissante du climat. Génétiquement, tous les deux sont des unités du relief très voisines du système zonal aride, morphographiquement ils présentent des différences.Le système morphodynamique et génétique de la zone aride (subtropicale et tropicale) constitue, à côté de la zone tropicale humide, l'un des grands ensembles morphoclimatiques du globe.

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Eine zusammenfassende, bisher unveröffentlichte Darstellung der Flächenbildung in ariden Klimagebieten hat der Verfasser erstmalig auf einem Symposium über Fragen der Flächenbildung in den Tropen und Subtropen in Saarbrücken im Oktober 1967 gegeben. Auf der Jahrestagung der Geologischen Vereinigung in Göttingen im Februar 1968 wurde ebenfalls über diesen Fragenkreis der klimageomorphologischen Forschung referíert. Dieser Beitrag gibt den Inhalt der genannten Vorträge wieder.     

Bestimmung polarer Phosphorsäureester in Trink‐ und Oberflächenwasser mittels HPLC‐MS‐MS

Determination of Organophosphorus Pesticides in Water by HPLC‐MS‐MS In the EC Water Framework Directive 2000/60/EG and in CEC 76/464/EEC there are 16 organophosphorus pesticides (insecticides and acaricides) listed which belong to so‐called priority substances. The committed quality aims of these substances frequently require maximum concentrations below 0.1 μg/L. In this paper a HPLC‐MS‐method is described. The reported limits of determination of organophosphorus pesticides are lower than the demanded limits. High analytical sensitivity is reached by solid‐phase extraction (SPE) and by injecting large volumes. For some of these substances no sample enrichment is needed and low detection limits are obtained by direct injection of the original water sample.     

Experimental and theoretical bond critical point properties for model electron density distributions for earth materials

Generalized X-ray scattering factor model experimental electron density distributions and bond critical point, bcp, properties generated in recent studies for the earth materials stishovite, forsterite, fayalite and cuprite with high energy single crystal synchrotron X-ray diffraction data and those generated with high resolution diffraction data for coesite and senarmonite were found to be adequate and in relatively good agreement, ~5% on average, with those calculated with quantum chemical methods with relatively robust basis sets. High resolution low energy single crystal diffraction data, recorded for the molecular sieve AlPO₄-15, were also found to yield model electron density distribution values at the bcp points for the AlO and PO bonded interactions that are in relatively good to moderately good agreement with the theoretical values, but the Laplacian values of the distribution at the points for the two bonded interactions were found to be in relatively poor agreement. In several cases, experimental bcp properties, generated with conventional low energy X-ray diffraction data for several rock forming minerals, were found overall to be in poorer agreement with the theoretical properties. The overall agreement between theoretical bcp properties generated with computational quantum methods and experimental properties generated with synchrotron high energy radiation not only provides a basis for using computational strategies for studying and modeling structures and their electron density distributions, but it also provides a basis for improving our understanding of the crystal chemistry and bonded interactions for earth materials. Theoretical bond critical point properties generated with computational quantum methods are believed to rival the accuracy of those determined experimentally. As such the calculations provide a powerful and efficient method for evaluating electron density distributions and the bonded interactions for a wide range of earth materials.Dedicated to Professor Robert F. Stewart of Carnegie Mellon University on his retirement for his brilliant and original work modeling electron density distributions.     

Isotope measurements and ground water flow modeling using MODFLOW for understanding environmental changes caused by a well field in semiarid Brazil

Measurements of the environmental isotopes carbon-14 and oxygen-18 and of the electrical conductivity in ground water, together with MODFLOW-88 (DOS) simulations of pumping tests, were used to achieve a detailed understanding of the functioning of an aquifer in the area of a well field. The methodology was applied in the sedimentary basin of the Cariri region, in the south of Ceará State in Brazil. Localized hydraulic connections between adjacent aquifer units could be detected, and mixing ratios for the contributions from the units involved were determined. Cone of depression simulations for a three-year drought period revealed well interference and a drastic lowering of the piezometric level, thereby explaining the hydrogeologic changes and transformations in vegetation that were observed in the area of the well field. The combined use of the modeling tools and the geochemical field observations is shown to provide more detailed insight into the conceptual model of the groundwater flow system.     

Area-Averaged Surface Fluxes Over the Litfass Region Based on Eddy-Covariance Measurements

Micrometeorological measurements (including eddy-covariance measurements of the surface fluxes of sensible and latent heat) were performed during the LITFASS-2003 experiment at 13 field sites over different types of land use (forest, lake, grassland, various agricultural crops) in a 20 × 20 km² area around the Meteorological Observatory Lindenberg (MOL) of the German Meteorological Service (Deutscher Wetterdienst, DWD). Significant differences in the energy fluxes could be found between the major land surface types (forest, farmland, water), but also between the different agricultural crops (cereals, rape, maize). Flux ratios between the different surfaces changed during the course of the experiment as a result of increased water temperature of the lake, changing soil moisture, and of the vegetation development at the farmland sites. The measurements over grass performed at the boundary-layer field site Falkenberg of the MOL were shown to be quite representative for the farmland part of the area. Measurements from the 13 sites were composed into a time series of the area-averaged surface flux by taking into account the data quality of the single flux values from the different sites and the relative occurrence of each surface type in the area. Such composite fluxes could be determined for about 80% of the whole measurement time during the LITFASS-2003 experiment. Comparison of these aggregated surface fluxes with area-averaged fluxes from long-range scintillometer measurements and from airborne measurements showed good agreement.     

Macroscopic representation of structural geometry for simulating water and solute movement in dual-porosity media

The structure of macroporous or aggregated soils and fractured rocks is generally so complex that it is impractical to measure the geometry at the microscale (i.e., the size and the shape of soil aggregates or rock matrix blocks, and the myriad of fissures or fractures), and use such data in geometry-dependent macroscale flow and transport models. This paper analyzes a first-order type dual-porosity model which contains a geometry-dependent coefficient, β, in the mass transfer term to macroscopically represent the size and shape of soil or rock matrix blocks. As a reference, one- and two-dimensional geometry-based diffusion models were used to simulate mass transport into and out of porous blocks of defined shapes. Estimates for β were obtained analytically for four different matrix block geometries. Values for β were also calculated by directly matching analytical solutions of the diffusion models for a number of selected matrix block geometries to results obtained with the first-order model assuming standard boundary conditions. Direct matching improved previous results for cylindrical macropore geometries, especially when relatively small ratios between the outer soil mantle and the radius of the inner cylinder were used. Results of our analysis show that β is closely related to the ratio of the effective surface area available for mass transfer, and the soil matrix volume normalized by the effective characteristic length of the matrix system. Using values of β obtained by direct matching, an empirical function is derived to estimate macroscopic geometry coefficients from medium properties which in principle are measurable. The method permits independent estimates of β, thus allowing the dual-porosity approach eventually to be applied to media with complex and mixed types of structural geometry.     

Long-term observation of volcanic tremor on Stromboli volcano (Italy): A synopsis

The features of seismic activity on Stromboli are discussed and compared in terms of their relationship with the main changes of volcanic activity from 1990 to 1993.We considered a statistical approach for our data analysis. Cluster analysis was used to seek out classes of spectra which might characterize the condition of the volcanic system. The classes we have found provide insights into a scenario which evolves through different phases of volcanic activity, from paroxysms to low activity. We show that episodes of lava effusion and lava fountaining are heralded by variations in the spectral features of tremor after a preparation time. This result highlights the importance of tremor, and reveals that long-term observations are key to examine slow modifications in a volcanic system such as Stromboli, characterized by open conduits, and persistent explosive activity.