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61.
62.
Dr. Manfred Behrens Armin Jansen Dipl.-Geol. Dr. Paul Wurster 《International Journal of Earth Sciences》1967,56(1):748-765
Zusammenfassung An vier feldgeologisch untersuchten Beispielen, dem Gräfenthaler Horst im Frankenwald, der Fränkischen Linie bei Kronach, der Kulmbacher Verwerfung bei Kirchleus und an Verwerfungszonen im Steigerwald wird gezeigt, daß die fränkischen Verwerfungen als Flächen eines zusammenhängenden Strukturfeldes angesehen werden können, das trotz seiner verschiedenartigen Erscheinungsformen im Grund- und Deckgebirge auf eine gemeinsame Ursache zurückgehen dürfte.
Herrn Professor Dr.Roland Brinkmann zum 70. Geburtstag gewidmet. 相似文献
Four areas in Northern Bavaria, the Gräfenthaler Horst in the Frankenwald, the Franconian Line near Kronach, the Kulmbach Fault near Kirchleus and fault zones in the Steigerwald, were investigated by different field methods. The authors are in the opinion that these Franconian faults are elements of a connecting structural region though different tectonic phenomena may be observed on the surface.
Résumé Dans le nord de la Bavière des grands accidents tectoniques de direction NW/ SE, dont quelques-uns traversent le socle hercynien, d'autres la couverture mésozoique avoisinante, ont été étudiés par des methodes diverses. Quoique leurs caractères changent selon l'étage affectée, ces accidents sont des élements d'un seul domaine structural et ont apparement une origine commune.
. , , , .
Herrn Professor Dr.Roland Brinkmann zum 70. Geburtstag gewidmet. 相似文献
63.
Dr. M. Behrens Dr. K. Krumsiek Dr. D. E. Meyer Dr. Essen A. Schäfer Prof. Dr. A. Siehl Dr. J. Stets Dr. J. Thein Prof. Dr. P. Wurster 《International Journal of Earth Sciences》1978,67(2):424-453
The Geological Institute of Bonn University since 1975 investigates in connection with DSDP/IPOD the Cretaceous of the Atlantic coastal basin in south-western Morocco. 30 main stratigraphic sections and numerous auxiliary ones were taken along several traverses, running along distances of 150 to 200 km in west-east direction. The recognized epicontinental facies-pattern along the traverse of the southern High Atlas mountain range depicts clearly, that we cut here the critical region of intertonguing marine, fine-clastic-carbonaceous sediments and continental detritic deposits. The littoral zone successively progrades with three major transgressions (Neocomian, Upper Aptian, Turonian) towards the African Continent. Sedimentation processes, stratigraphy, paleomagnetics, geochemistry, sedimentology and paleogeography are investigated, taking selected horizons on one hand and complete stratigraphic columns on the other. A new sedimentation model reflecting transgression and regression events in the Cretaceous “Atlas Gulf” show some probabilities of eustatic sea-level changes. There are similarities between the Atlas Gulf and other coastal basins on both sides of the Atlantic Ocean. There are certain relations between the sedimentary record of the proand regrading littoral zone on the continent and in the nearby deep sea deposits. There is an exciting coincidence between the stratigraphie succession of the downwarping Atlas Gulf and the sedimentary cover of the interior of Africa, especially the Mesozoic Sahara Basin. 相似文献
64.
65.
Jörn Behrens Lothar Dresen Ludvík Waniek Rezensent V. Červený 《Studia Geophysica et Geodaetica》1971,15(2):147-160
Summary Following the recommendation of the European Seismological Commission (Copenhagen 1966) to carry out comparative measurements on simple seismic models with a prescribed velocity-depth distribution (test models), an attempt was made to compare results obtained with different model techniques. In the present paper, model investigations with the first two proposed test models carried out by 2- and 3-dimensional model techniques are described. Seismogrammes, travel-time curves and amplitude-distance curves of the models investigated are given. A quantitative comparison of the results shows a satisfactory agreement. 相似文献
66.
A standardized method for sampling and extraction methods for quantifying microplastics in beach sand 总被引:1,自引:0,他引:1
Aiken Besley Martina G. Vijver Paul Behrens Thijs Bosker 《Marine pollution bulletin》2017,114(1):77-83
Microplastics are ubiquitous in the environment, are frequently ingested by organisms, and may potentially cause harm. A range of studies have found significant levels of microplastics in beach sand. However, there is a considerable amount of methodological variability among these studies. Methodological variation currently limits comparisons as there is no standard procedure for sampling or extraction of microplastics. We identify key sampling and extraction procedures across the literature through a detailed review. We find that sampling depth, sampling location, number of repeat extractions, and settling times are the critical parameters of variation. Next, using a case-study we determine whether and to what extent these differences impact study outcomes. By investigating the common practices identified in the literature with the case-study, we provide a standard operating procedure for sampling and extracting microplastics from beach sand. 相似文献
67.
Michael J. Krawczynski Timothy L. Grove Harald Behrens 《Contributions to Mineralogy and Petrology》2012,164(2):317-339
The water-saturated phase relations have been determined for a primitive magnesian andesite (57 wt% SiO2, 9 wt% MgO) from the Mt. Shasta, CA region over the pressure range 200–800 MPa, temperature range of 915–1,070 °C, and oxygen fugacities varying from the nickel–nickel oxide (NNO) buffer to three log units above NNO (NNO+3). The phase diagram of a primitive basaltic andesite (52 wt% SiO2, 10.5 wt% MgO) also from the Mt. Shasta region (Grove et al. in Contrib Miner Petrol 145:515–533; 2003) has been supplemented with additional experimental data at 500 MPa. Hydrous phase relations for these compositions allow a comparison of the dramatic effects of dissolved H2O on the crystallization sequence. Liquidus mineral phase stability and appearance temperatures vary sensitively in response to variation in pressure and H2O content, and this information is used to calibrate magmatic barometers-hygrometers for primitive arc magmas. H2O-saturated experiments on both compositions reveal the strong dependence of amphibole stability on the partial pressure of H2O. A narrow stability field is identified where olivine and amphibole are coexisting phases in the primitive andesite composition above 500 MPa and at least until 800 MPa, between 975–1,025 °C. With increasing H2O pressure (\({P}_{\text {H}_2{\rm O}}\)), the temperature difference between the liquidus and amphibole appearance decreases, causing a change in chemical composition of the first amphibole to crystallize. An empirical calibration is proposed for an amphibole first appearance barometer-hygrometer that uses Mg# of the amphibole and \(f_{\text {O}_2}\):This barometer gives a minimum \({P}_{\text{H}_{2}{\rm O}}\) recorded by the first appearance of amphibole in primitive arc basaltic andesite and andesite. We apply this barometer to amphibole antecrysts erupted in mixed andesite and dacite lavas from the Mt. Shasta, CA stratocone. Both high H2O pressures (500–900 MPa) and high pre-eruptive magmatic H2O contents (10–14 wt% H2O) are indicated for the primitive end members of magma mixing that are preserved in the Shasta lavas. We also use these new experimental data to explore and evaluate the empirical hornblende barometer of Larocque and Canil (2010).
相似文献
$$ P_{\text{H}_{2}{\rm O}}({\rm MPa})=\left[{\frac{{\rm Mg\#}}{52.7}}-0.014 * \Updelta {\rm NNO}\right]^{15.12} $$
68.
Jan Behrens Corné P. J. M. van Elzakker Manuela Schmidt 《The Cartographic journal》2013,50(2):177-184
The objective of this study is to investigate the usability of the iD editor of OpenStreetMap (OSM). To this end a usability test with 18 participants has been conducted. The participants were given mapping tasks to complete using iD and observed with the thinking aloud method as well as screen recording and mouse/keyboard logging. Additionally, the test persons were interviewed after each test. The data gathered were analysed with regard to key usability criteria such as learnability, efficiency, error tolerance, and subjective user satisfaction. The outcome of this study is the identification of usability issues from which possible improvements of the tool have been derived. The study shows that iD is an overall usable tool for novice users, but still shows opportunities for improvement especially in terms of learnability and error handling. 相似文献
69.
57Fe Mössbauer spectra of iron bearing alumino-silicate glasses are analysed by two complementary methods (SID and x-VBF) especially adapted for the analysis of disordered systems by taking into account distributions of hyperfine Mössbauer parameters. Qualitative and quantitative information about the oxidation state of iron are obtained as well as information about the distribution of local environments of iron. The possibility to separate the signal of ferric iron from that of ferrous iron allows to derive precise redox ratio in favourable cases but also to analyse more sharply the different contributions to Mössbauer spectra. Using two different glass series (feldspar composition, haplo-tonalitic composition), the characteristics of the two methods are described and employed to study the effect of composition, water incorporation and oxidation state on the glass structure. Optical absorption spectroscopy is used to support the interpretation of the Mössbauer spectra in case of the feldspar glasses. 相似文献
70.
Alexander?BorisovEmail authorView authors OrcID profile Harald?Behrens Francois?Holtz 《Contributions to Mineralogy and Petrology》2018,173(12):98
The effect of MgO and total FeO on ferric/ferrous ratio in model multicomponent silicate melts was investigated experimentally in the temperature range 1300–1500 °C at 1 atm total pressure in air. We demonstrate that the addition of these weak network modifier cations results in an increase of Fe3+/Fe2+ ratio in both mafic and silicic melts. Based on present and published experimental data, a new empirical equation is proposed to predict the ferric/ferrous ratio as a function of oxygen fugacity, temperature and melt composition. In contrast to previous equations, the compositional effect of melts on the Fe3+/Fe2+ ratio is not only modeled by the sum of the molar fraction of the individual oxide components. Additional interactions terms have also been incorporated. The main advantage of the proposed model is its applicability for a wide compositional range. However, its application to felsic melts (>?68 wt% SiO2) is not recommended. Other advantages of this equation and differences when compared with previous models are discussed. 相似文献