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  • 1
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    Berlin ; Heidelberg : Springer
    Description / Table of Contents: INTRODUCTION The evaporite deposits of the Werra district, especially in the Hattorf mining field, are considered a worldwide unique location for the occurence of numerous basalt dikes and magmatic fluid phases fixed in salt rocks. In spite of the great number of studies dealing with the magmatites in the Werra region, previous investigations have rarely attempted more than a predominantly 'qualitative' description of the basaltic rocks and the effects of volcanism on the evaporites (see Chapter 2). The method of interpreting the mineralogical and chemical composition of the evaporites at the basalt contact is based on previous works (KNIPPING 1984; KNIPPING & HERRMANN 1985). This study should contribute to understanding (i) the mechanism of intrusion of the basaltic rnelts and (ii) the metamorphic processes occurring in the evaporites caused by mobile phases during volcanism. Hence, the following methods were applied: The mineralogical and chemical description of the basaltic rocks with recent nomenclature including the possible differences between individual dikes and between surface- and subsurface-exposed basalts. Seven surface and 48 subsurface exposures at the Hattorf mine of Kali & Salz AG were studied. Application of the most recent knowledge on basalt genesis for interpreting observational and experimental results. Studies on the sulfur and carbon isotope distributions of the native sulfur from several subsurface exposures and the enrichments of gases (predominantly CO2) in the evaporites. Calculation of the spatial and temporal temperature distribution in the evaporite rocks following intrusion of the basaltic melts. For purposes of clarity a few of the terms which will be used frequently here will first be defined: basalt - all of the intrusive rocks studied can be assigned mineralogically and chemically to the basalt family in a broader sense. Thus, the terms basaltic rock or, in short, basalt will be used for these rocks. rock salt - instead of the term salt for halitic rocks the term rock salt is used. Besides, the evaporites are generally designated as host rocks (for the basalt dikes) as well. gases - especially in the German literature the term carbon dioxide or carbonic acid (= Kohlensäure) is frequently used for the gases enclosed in the evaporites of the Werra-Fulda district. ACKERMANN et al (1964) found, in addition to carbon dioxide, considerable amounts of nitrogen and minor amounts of methane. In the following therefore the terms gas mixture or gas will be used. The various basalt dikes found in the Hattorf mining field are described here in terms of their mineralogy and geochemistry for the first time. In doing so it is necessary to number them from east to west. To avoid confusion with older numerations (e.g. SIEMENS 1971) the various dike systems are designated by capital letters (A to P).
    Pages: Online-Ressource (131 Seiten)
    ISBN: 9783540513087
    Language: English
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  • 2
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    Berlin ; Heidelberg : Springer
    Description / Table of Contents: Cellular growth is an important crystal growth process and offers an interesting example of natural pattern formation. The present work has been undertaken to study cellular growth, especially its pattern formation, both experimentally and numerically. In situ observations of faceted cellular growth clearly revealed cellular interactions in the array of cells. Cell tip splitting and loss of cells were observed to be the two main mechanisms for the adjustment of cell spacings during growth. For the first time, the true time-dependent faceted cellular growth has been modelled properly. The time evolution of faceted cellular growth has demonstrated the dynamical features of cellular growth processes. It was shown that the pattern formation was determined by cellular interactions in the array, either transient or persistent depending on the growth condition. The cellular structures were irregular when persistent interactions occurred, whereas relatively regular structures could be formed once the transient interactions had stopped. As a result of cellular interactions, a finite range of stable cell spacings was found under a given growth condition. Numerical experiments were carried out for k 〉 1 and k 〈 1 (where k is the solute partition coefficient), under a number of different growth conditions. It was found that these two cases were not symmetric as far as solute distribution is concerned; however the pattern formation behaviours were similar. For k 〉 1 shallow cells were retained, while for k 〈 1, the formation of liquid grooves along the cell boundary depended on the growth condition. The solute effect plays an important role in the cellular interactions in the array. The results were compared with experimental observations in thin film silicon single crystals. It is felt that a general behaviour of pattern formation is found and should be expected for other processes such as non-faceted cellular or eutectic growth. In addition, the solute flow in steady state cellular array growth was studied using the point source technique. Preliminary work was carried out to measure steady state non-faceted cell shapes. Heat flow in zone melting was studied numerically.
    Pages: Online-Ressource (208 Seiten)
    ISBN: 9783540544852
    Language: English
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  • 3
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    Berlin ; Heidelberg : Springer
    Description / Table of Contents: The present interest in sediments which are rich in organic matter results not only from their economic significance as potential oil and gas source rocks, but also from the fact that their deposition is the result of special environments. Subtle changes in the environmental conditions may result in great variations in the geochemical and petrographical characteristics of the organic matter. Therefore, the study of organic matter-rich sediments can provide a key to past sedimentary conditions. In addition, the elucidation of the depositional controls is of importance for oil and gas exploration strategies, for which the knowledge of source rock distribution and quality is critical. Furthermore, organic matter reacts extremely sensitive to changes in temperature during burial. The result of this sensitivity is the generation of volatile products such as carbon dioxide, water, nitrogen, oil and gas and a reorganization of the solid organic residue. Some of these changes are quantified as maturity parameters which can be used as calibration tools in basin modelling, i.e., in the modelling of temperature histories of sedimentary basins. The use of maturity parameters and other organic matter characteristics as indicators for diagenetic conditions and depositional processes is, however, restricted, if analyses are performed on outcrop samples, because weathering also affects organic matter.
    Pages: Online-Ressource (216 Seiten)
    ISBN: 9783540566618
    Language: English
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  • 4
    Description / Table of Contents: PREFACE It is increasingly necessary to develop industrial and hydraulic engineering constructions under unfavourable geological or geotechnical conditions. Furthermore, it becomes more and more important to build effectively and economically and to find optimal solutions for a long-term steady function of the constructions. This emphatically demands exhaustive information on the structural situations and engineering parameters of local site assessments by areal investigations of the sites and the petrophysical parameters in situ. This requires, however, the use of geophysical techniques. During the last two or three decades international applied geophysics has systematically developed new possibilities for site investigations for the determination of petrophysical parameters in situ as well as for observation of the system building and site. As in "New techniques in engineering", geophysical methods make it possible to develop areal models of subsurface conditions of building sites, to quantify relevant engineering parameters in situ, as well as to analyze the longterm behaviour of the buildings, which are influenced by internal or external factors. With regard to the broad spectrum of applied geophysics, there are few methods, that especially favour application in engineering and groundwater studies. These methods are distinguished by a relatively simple measuring technique and good measuring progress, e.g. the geoelectrical self-potential method, the geoelectrical resistivity method as well as a newly developed devices for geothermic measurements. There exist numerous publications, broadly scattered in the technical literature, concerning the theoretical bases and applications of these methods, but until now, there have been only a few meetings to exchange experience and results on an international level. This was the aim of the symposium "Detection of Subsurface Flow Phenomena by Self-Potential/Geoelectrical and Thermometric Methods", held in Karlsruhe from 14-18 March 1988. An outstanding part of the symposioum was represented by the results of a research project, coordinated by the University of Karlsruhe (Department of Geology and Institute of Soil and Rock Mechanics) and the Federal Waterway Engineering and Research Institute (BAW), Karlsruhe. Regarding the subject "Experiments to ascertain the relations between hydraulic potentials in the underground and the geoelectrical and thermic potentials set off by these", the research work took four years. The project was sponsered by the Volkswagen Foundation/Hannover. The goal was to develop and test objective techniques for detecting leakages in dams, locating, demarcating and designating quantitatively inhomogeneous spheres in dams with the aim of detecting damage and subsurface flow phenomena as soon as possible. The symposium consisted of a three-day lecture meeting with about 40 papers and a summarizing respectively closing roundtable discussion, a visit to the laboratories and to the in situ constructions within the area of BAW developed in the frame of the research project. This included a technical excursion to the Rhine-Staustufe Iffezheim with its very impressive waterway constructions and an excursion to the Geophysical Observatory near Schiltach (Black Forest). The Observatory belongs to the Universities of Karlsruhe and Stuttgart. Approximately 80 scientists from 15 countries participated the symposium. They were welcomed by the Rector of the University, Professor Dr. A. Kunle and the representative of the Federal Ministry of Traffic, Dr. G. Schröder. Professor Dr. H. Hötzl elucidated the scientific problems and the economical importance of the project as a speaker of the research group. The following papers dealt with the fundamental aspects of geoelectrical and thermometric measurements, with the theory of these methods, the state and developing ter~dencies concerning devices, data acquisition, processing and interpretation as well as noise effects. It became clear that the solution of the complex scientific-technical problems of waterway constructions and environmental protection requires broad, interdisciplinary cooperation and international collaboration. Thus it would be possible to minimize the personnel, temporal and economic efforts. The intended cooperation of geoscientists, engineering geologists, building engineers and representatives of other disciplines make it possible, not only to exchange experiences and results relating to international problems unsolved until now, but also to determine new guidelines with regard to the scientific organization of further investigations. Thus in order to inform all interested parties of the main topics of the symposium and to advance international cooperation in the future, the present review includes a part of the papers and reports of the excursions recommended by the participants of the meeting, which have been divided into the following topics: - Introduction to engineering-geophysical problems and attempts at their solution; - Geoelectrical self-potential measurements; - Geoelectrical resistivity measurements; - Geothermic measurements; - Case histories; - Some topics of the roundtable discussion; - Reports concerning the excursions. The editors wish to thank very much all those, who contributed to the success of the symposium and to the publication of the present report. Finally they venture the note, that the authors theirselves are responsible for the content of their papers.
    Pages: Online-Ressource (514 Seiten)
    ISBN: 9783540518754
    Language: English
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  • 5
    facet.materialart.
    Berlin ; Heidelberg : Springer
    Description / Table of Contents: PREFACE The aim of this volume is two-fold. At the more pragmatic level, it is to help answer the many questions about the structure of the Pacific continental margin of North America, which have arisen over the years as a result of continuing field mapping and geophysical surveys. The second objective is methodological - to illustrate the irreplaceable role of geological information among the various data sets used in earth-science studies. The need to address these issues became apparent to the author during the several years he spent taking part in geological and geophysical studies on the west coast of Canada. All too often, results of geologic field mapping disagreed with tectonic predictions from too-straightforward local applications of global plate reconstructions, which due to their generality do not always take a full account of specific character of particular regions. To be sure, the global approach has during the last q~/artercentury greatly expanded the vision of geoscientists, previously restricted to continental regions. However, a negative by-product of this expansion has been a decline of attention paid to local information, as tectonic studies have increasingly relied on simply fitting the development of a particular region into this or that prefabricated tectonic template. Direct geological observations have limitations of their own. The observer in most cases deals with products of geologic processes, rather than with the processes themselves. Field mapping provides local information, and many years of effort are needed before a regional overview becomes possible. Geologic mapping is restricted to the ground surface, and even the deepest drillholes cannot sample more than the outermost shell of the Earth. The factual side of geologic mapping is usually limited to determination of rock types and their relationships in areas of exposure. Conclusions about the three-dimensional structure of a region and its evolution are still mostly inferential. Broad incorporation into geological studies of geophysical data, assisted by ever-more-sophisticated modern computers, provides a huge volume of information unobtainable in other ways. Geophysical methods quickly afford regional coverage or images of the Earth's deep interior. Geophysical methods have prompted the application in geological sciences of methodologies borrowed from exact sciences, such as mathematics and physics. Particularly important has been quantitative modeling, which allows a scientist to use the known parameters of a system to predict others. But in taking this approach too far, one encounters a dangerous pitfall. A model is a simplified representation of a natural phenomenon. The quality of this or that representation is relative, and a representation is never perfect. To incorporate all characteristics of a geologic phenomenon, in a parametrized form, into a numerical or physical imitation is impossible. This requires one to rely on simplifying assumptions, and a model is no better than the assumptions at its base. Unrealistic assumptions lead to unrealistic models. When a disagreement arises between model predictions and observations - such as those from geologic field mapping - a modeler may be tempted to downplay the differences or the significance of the offending observations. It becomes tempting to underestimate the role of an experienced geologist as a principal arbiter of the realism of a model. But it is geological data and geological control that provide the ultimate means of testing abstract models. From this methodological position, the present study of the western North American continental margin is organized as follows: 1. Geological information, available from field mapping and drilling, is gathered and summarized. 2. Current geophysical models for this region are considered, with particular attention to their underlying assumptions. 3. The available data, geological and geophysical, are synthesized into an internally consistent geologic-evolution concept. 4. This concept is tested by comparison with direct geological observations from field mapping and drilling. Because most current data sets and models cover northwestern Washington and western British Columbia, particular attention was paid to these areas. Fortunately, these areas contain many keys that help understand the structure of the entire western North American continental margin, which has baffled scientists for decades. The author does not claim to have resolved all these problems, but he does believe he has made a useful contribution to understanding continental-oceanic plate interrelations at this continental margin. Rigidity of lithospheric plates is a critical assumption in current models of plate evolution. The lithophere of a plate is created at spreading centers manifested in the global system of mid-ocean ridges. It moves away from the place of its birth towards boundaries with other plates, with which it can interact in a variety of ways. Some interactions are of strike-slip type, with two plates simply sliding past each other. However, to compensate for the creation of new lithosphere at spreading centers, older lithosphere at some plate boundaries descends into the mantle as it is overriden by other plates. At such plate boundaries lie subduction zones. If both regimes occur along a single plate boundary, the transition between them must be abrupt. Unless it can be tied to a change in orientation of the boundary, it must be associated with a junction of not two, but three different plates. Such a template was used to interpret the structure and tectonic evolution of the western North American continental margin in the late 1960s and thereafter (Atwater, 1970; McManus et al., 1972; Barr and Chase, 1974; Riddihough and Hyndman, 1976). To satisfy the principles of rigid-plate tectonics, both regimes have to exist along this continental margin. Also needed in rigid-plate reconstructions is a plate triple junction somewhere between the areas of proven ongoing subduction (in Oregon and southern Washington) and transform plate motion (along the southeastern Alaska margin; Atwater, 1970; McManus et al., 1972). Such a triple junction has been placed off Queen Charlotte Sound offshore British Columbia (Keen and Hyndman, 1979; Riddihough et al., 1983), where a spreading center has been postulated between the Pacific and Explorer oceanic plates (Hyndman et al. 1979; Riddihough, 1984). Off northern Vancouver Island, a transform boundary between the Explorer and Juan de Fuca oceanic plates has been postulated, but both these plates are assumed to be subducting beneath Vancouver Island (Hyndman et al., 1979; Riddihough and Hyndman, 1989)o With the assumed universality of the rigid-plate model, "broad similarity" has been suggested between the geology of western Oregon and that of western British Columbia, and the Cascadia zone of active subduction has been extended as far north as the mouth of Queen Charlotte Sound (Riddihough, 1979, 1984). An accretionary sedimentary prism (Yorath, 1980) - or even an accretionary complex containing several exotic "terranes" (Davis and Hyndman, 1989) - has been postulated off Vancouver Island. Geological observations onshore and offshore (Shouldice, 1971; Tiffin et al., 1972) have come to be considered too "surficial" to be of major consequence for large-scale tectonic modeling (Yorath et al., 1985a,b; Yorath, 1987). Variants of the principal geophysical model for this area during the last decade (Clowes et al., 1987; Hyndman et alo, 1990; Spence et al. 1991; Yuan et al., 1992; Dehler and Clowes, 1992) have become increasingly distant from geological observations. As new model variants emerged, they were checked for internal consistency, compatibility with neighboring local models and fidelity to the overall assumed tectonic picture. However, detailed geological work continued, and many of its results proved incompatible with the conventional wisdom (Gehrels, 1990; Babcock et al., 1992, 1994; Allan et al., 1993; Lyatsky, 1993a). Importantly, questions arose about the applicability in this region of the conventional, simple rigid-plate assumption, as it was shown to be unable to account for all the geological and geophysical peculiarities in some areas (Carbotte et al., 1989; Allan et al., 1993; Davis and Currie, 1993). New solutions were made necessary by new findings and by rediscovery of forgotten old data (see Lyatsky et al., 1991; Lyatsky, 1993b). Without aiming to resolve all the outstanding debates, tectonic implications of the geologic mapping and drilling results in this region are considered in the following chapters. These results are integrated with geochemical and geophysical data. Interpretations of these data, made by this author and by other workers, are verified by geological observations and by geologically plausible extrapolations from these observations. In searching for solutions consistent with all the information, the author has restricted himself to analyzing continental-crust structures along this continental margin. He believes, however, that future models for the offshore regions of the northeastern Pacific should consider the results obtained herein.
    Pages: Online-Ressource (352 Seiten)
    ISBN: 9783540608424
    Language: English
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  • 6
    Keywords: air-sea exchange processes and flux ; geochemical processes in seawater ; primary production and other biological processes ; particle flux and sediment geochemistry ; submarine hydrothermal processes ; modeling and physical oceanography
    Description / Table of Contents: Chapter I. Air-Sea Exchange Processes and Flux --- Chemical composition of marine aerosols over the Central North Pacific—Results ftom the 1991 cruise of Hakurei Maru No. 2 / Uematsu, M., Kawamupa, K., Ibusuki, T. and Kimoto, T. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 3-14 --- Estimation of mineral aerosol fluxes to the Pacific by using environmental plutonium as a tracer / Nakanishi, T., Shiba, Y., Muramatsu, M. and Haque, M. A. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 15-30 --- Land-derived lipid class compounds in the deep-sea sediments and marine aerosols from the North Pacific / Kawamura, K. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 31-51 --- Iron and manganese in the atmosphere and oceanic waters / Nakayama, E., Obata, H., Okamura, K., Isshiki, K., Karatani, H. and Kimoto, T. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 53-68 --- Laboratory estimation of CO2 transfer velocity across the air-sea interface / Komom, S., Shimada, T. and Murakami, Y. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 69-81 --- Dissolution of calcareous tests in the ocean and atmospheric carbon dioxide / Nozaki, Y. and Oba, T. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 83-92 --- Calcium carbonate production and carbon dioxide flux on a coral reef, Okinawa / Ohde, S. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 93-98 --- Chapter II. Geochemical Processes in Seawater --- Generations of carbonyl sulfide and hydrogen peroxide in the Seto Inland Sea—Photochemical reactions progressing in the coastal seawater / Fujiwara, K., Takeda, K. and Kumamoto, Y. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 101-127 --- Speciation of organoarsenical compounds in the hydrosphere / Sohrin, Y., Hasegawa, H. and Matsui, M. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 129-138 --- Chemical speciation of selenium in natural waters / Nakaguchi, Y., Koike, Y. and Hiraki, K. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 139-158 --- The concentration distribution and chemical form of arsenic compounds in seawater / Tanaka, S. and Santosa, S. J. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 159-170 --- The rare earth elements and yttrium in the coastal/offshore mixing zone of Tokyo Bay waters and the Kuroshio / Nozaki, Y. and Zhang, J. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 171-184 --- The tetrad effect in seawater; a long dispute and an analytical approach to the confirmation of the effect / Akagi, T. and Masuda, A. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 185-199 --- Detection, characterization and dynamics of dissolved organic ligands in oceanic waters / Tanoue, E. and Midorikawa, T. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 201-224 --- Chapter III. Primary Production and Other Biological Processes --- Nitrate assimilation and new production in open ocean / Kanda, J. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 227-238 --- Primary production and community respiration in the subarctic water of the western North Pacific / Odate, T. and Furuya, K. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 239-253 --- Effects of a seamount on phytoplankton production in the western Pacific Ocean / Furuya, K., Odate, T. and Taguchi, K. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 255-273 --- Marine colloids: Their roles in food webs and biogeochemical fluxes / Nagata, T. and Koike, I. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 275-292 --- Regional and seasonal variations of biomass and bio-mediated materials in the North Pacific Ocean / Yanada, M. and Maita, Y. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 293-306 --- Nitrogen and carbon stable isotopic ecology in the ocean: The transportation of organic materials through the food web / Sugisakj, H. and Tsuda, A. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 307-317 --- The role of carnivorous zooplankton, particularly chaetognaths in ocean flux / Terazaki, M. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 319-330 --- Seasonal changes in deep-sea benthic foraminiferal populations: Results of long-term observations at Sagami Bay, Japan / Kitazato, H. and Ohga, T. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 331-342 --- Chapter IV. Particle Flux and Sediment Geochemistry --- Spatial variation of Al flux in the North Pacific observed with sediment trap / Noriki, S., Iwai, T., Shimamoto, A., Tsunogai, S. and Harada, K. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 345-354 --- Spatial and temporal variation of δ515N in sinking particles in deep waters: Its implication for the origin and transport of particulate organic matter / Nakatsuka, T., Handa, N. and Imaizumi, S. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 355-374 --- 230Th and 231Pa distributions in surface sediments off Enshunada, Japan / Taguchi, K. and Narita, H. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 375-382 --- Remobilization of transition elements in pore water of continental slope sediments / Kato, Y., Tanase, M., Minami, H. and Okabe, S. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 383-405 --- Geochemistry of pore waters from a bathyal Calyptogena community off Hatsushima Island, Sagami Bay, Japan / Masuzawa, T., Nakatsuka, T. and Handa, N. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 407-421 --- Chapter V. Submarine Hydrothermal Processes --- Wide variation of chemical characteristics of submarine hydrothermal fluids due to secondary modification processes after high temperature water-rock interaction: a review / Gamo, T. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 425-451 --- Geochemistry of phase-separated hydrothermal fluids of the North Fiji Basin, Southwest Pacific / Ishibashi, J. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 453-467 --- Chemical modeling of seawater-rock interaction: Effect of rock-type on the fluid chemistry and mineral assemblage / Chiba, H. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 469-486 --- Hydrothermal mineralization in the Mid-Okinawa Trough / Nakashima, K., Sakai, H., Yoshida, H., Chiba, H., Tanaka, Y., Gamo, T., Ishibashi, J. and Tsunogai, U. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 487-508 --- Iron-rich smectite formation in the hydrothermal sediment of Iheya Basin, Okinawa Trough / Masuda, H. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 509-521 --- Formation and alteration of organic compounds in simulated submarine hydrothermal vent environments / Kobayashi, K., Kohara, M., Gamo, T. and Yanagawa, H. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 523-535 --- Localized heat flow anomalies in the middle Okinawa Trough associated with hydrothermal circulation / Kinoshita, M. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 537-559 --- Chapter VI. Modeling and Physical Oceanography --- Material transport models from Tokyo Bay to the Pacific Ocean / Yanagi, T. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 563-574 --- Climate and weather effects on the chlorophyll concentration in the northwestern North Pacific / Sugimoto, T., Tadokoro, K. and Furushima, Y. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 575-592 --- Ecosystem models for the three regional problems in the Northern Pacific / Kishi, M. J. and Kawamiya, M. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 593-611 --- A review on the subtropical mode water of the North Pacific (NPSTMW) / Hanawa, K. and Suga, T. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 613-627 --- Flow distribution at 165°E in the Pacific Ocean / Kawabe, M. and Taira, K. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 629-649 --- Determination of monthly mean sea surface temperature from 1981 to 1990 by the NOAA-AVHRR in the equatorial Pacific / Kishino, M. / Biogeochemical Processes and Ocean Flux in the Western Pacific, / pp. 651-659
    Pages: Online-Ressource (IX, 672 Seiten)
    ISBN: 4887041160
    Language: English
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  • 7
    Description / Table of Contents: PREFACE The CERN Accelerator School (CAS) was founded in 1983 with the aim to preserve and disseminate the knowledge accumulated at CERN (European Organization for Nuclear Research) and elsewhere on particle accelerators and storage rings. This is being achieved by means of a biennial programme of basic and advanced courses on general accelerator physics supplemented by specialized and topical courses as well as Workshops. The chapters included in this present volume are taken from one of the specialized courses, Applied Geodesy for Particle Accelerators, held at CERN in April 1986. When construction of the first large accelerators started in the 1950's, it was necessary to use geodetic techniques to ensure precise positioning of the machines' components. Since that time the means employed have constantly evolved in line with technological progress in general, while a number of specific developments - many of them achieved at CERN - have enriched the range of available instruments. These techniques and precision instruments are used for most of the world's accelerators but can also be applied in other areas of industrial geodesy: surveying of civil engineering works and structures, aeronautics, nautical engineering, astronomical radio-interferometers, metrology of large dimensions, studies of deformation, etc. The ever increasing dimensions of new accelerators dictates the use of the best geodetic methods in the search for the greatest precision, such as distance measurements to 10 -7, riqorous evaluation of the local geoid and millimetric exploitation of the Navstar satellites. At the same time, the powerful computer methods now available for solving difficult problems are also applicable at the instrument level where data collection can be automatically checked. Above all, measuring methods and calculations and their results can be integrated into data bases where the collection of technical parameters can be efficiently managed. In order to conserve the logical presentation of the different lectures presented at the CAS school, the chapters presented here have been grouped under four main topics. The first and the fourth deal with spatial and theoretical geodesy, while the second and third are concerned with the work of applied geodesy, especially that carried out at CERN. Readers involved in these subjects will find in the following chapters, if not the complete answer to their problems, at least the beginning of solutions to them.
    Pages: Online-Ressource (393 Seiten)
    ISBN: 9783540182191
    Language: English
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  • 8
    Description / Table of Contents: Starting from a more general discussion of mechanisms controlling organic carbon deposition in marine environments and indicators useful for paleoenvironmental reconstructions, this study concentrates on detailed organic-geochemical and sedimentological investigations of late Cenozoic deep-sea sediments from (1) the Baffin Bay and the Labrador Sea (ODP-Leg 105), (2) the upwelling area off Northwest Africa (ODP-Leg 108), and (3) the Sea of Japan (ODP-Leg 128). Of major interest are shortas well as long-term changes in organic carbon accumulation during the past 20 m.y. As shown in the data from ODP-Legs 105, 108, and 128, sediments characterized by similar high organic carbon contents can be deposited in very different environments. Thus, simple total organic carbon data do not allow (i) to distinguish between different factors controlling organic carbon enrichment and (ii) to reconstruct the depositional history of these sediments. Data on both quantity and composition of the organic matter, however, provide important informations about the depositional environment and allow detailed reconstructions of the evolution of paleoclimate, paleoceanic circulation, and paleoproductivity in these areas. The results have significant implications for quantitative models of the mechanisms of climatic change. Furthermore, the data may also help to explain the formation of fossil black shales, i.e., hydrocarbon source rocks. (1) BAFFIN BAY AND LABRADOR SEA The Miocene to Quaternary sediments at Baffin Bay Site 645 are characterized by relatively high organic carbon contents, most of which range from 0.5% to almost 3%. This organic carbon enrichment was mainly controlled by increased supply .of terrigenous organic matter throughout the entire time interval. Two distinct maxima were identified: (i) a middle Miocene maximum, possibly reflecting a dense vegetation cover and fluvial sediment supply from adjacent islands, that decreased during late Miocene and early Pliocene time because of expansion of tundra vegetation due to global climatic deterioration; (ii) a late Pliocene-Pleistocene maximum possibly caused by glacial erosion and meltwater outwash. Significant amounts of marine organic carbon were accumulated in western Baffin Bay during middle Miocene time, indicating higher surface-water productivity (up to about 150 gC m -2 y-l) resulted from the inflow of cold and nutrient-rich Arctic water masses. The decrease in average surface-water productivity to values similar to those of the modern Baffin Bay was recorded during the late Miocene and was probably caused by the development of a seasonal sea-ice cover. At Labrador Sea Sites 646 and 647, organic carbon contents are low varying between 0.10% and 0.75%; the origin of most of the organic matter probably is marine. A major increase in organic carbon accumulation at Site 646 at about 7.2 Ma may indicate increased surface-water productivity triggered by the onset of the cold East-Greeniand Current system. Near 2.4 Ma, i.e., parallel to the development of major Northern Hemisphere Glaciation, accumulation rates of both organic carbon and biogenic opal decreased, suggesting a reduced surface-water productivity because of the development of dosed seasonal sea-ice cover in the northern Labrador Sea. The influence of varying sea-ice cover on surface-water productivity is also documented in the short-term glacial/interglacial fluctuations in organic carbon deposition at Sites 646 and 647. (2) UPWELLING AREAS OFF NORTHWEST AFRICA The upper Pliocene-Quaternary sediments at coastal-upwelling Site 658 are characterized by high organic carbon contents of 4%; the organic matter is a mixture of marine and terrigenous material with a dominance of the marine proportion. The upper Miocene to Quaternary pelagic sediments from close-by non-upwelling Sites 657 and 659, on the other hand, display low organic carbon values of less than 0.5%. Only in turbidites and slumps occasionally intercalated at the latter two sites, high organic carbon values of up to 3% occur. The high accumulation rates of marine organic carbon recorded at Site 658 reflect the high-productivity upwelling environment. Paleoproductivity varies between 100 and 400 gC m "2 y-1 during the past 3.6 m.y. and is clearly triggered by changes in global climate. However, there is no simple relationship between climate and organic carbon supply, i.e., it is not possble to postulate that productivity was generally higher at Site 658 during glacials than during interglacials or vice versa. Changes in the relative importance between upwelling activity (which was increased during glacial intervals) and fluvial nutrient supply (which was increased during interglacial intervals) may have caused the complex productivity record at Site 658. Most of the maximum productivity values, for example, were recorded at peak interglacials and at terminations indicating the importance of local fluvial nutrient supply at Site 658. Near 0.5 Ma, a long-term decrease in paleoproductivity occurs, probably indicating a decrease in fluvial nutrient supply and/or a change in nutrient "content of the upwelled waters. The former explanation is supported by the contemporaneous decrease in terrigenous organic carbon and (river-borne) clay supply suggesting an increase in long-term aridity in the Central Sahara. At Site 660, underneath the Northern Equatorial Divergence Zone, (marine) organic carbon values of up to 1.5% were recorded in upper Pliocene-Quaternary sediments. During the last 2.5 Ma, the glacial sediments are carbonate-lean and enriched in organic carbon probably caused by the influence of a carbonate-dissolving and oxygen-poor deep-water mass. (3) SEA OF JAPAN Based on preliminary results of organic-geochemical investigations, the Miocene to Quaternary sediments from ODP-Sites 798 (Oki Ridge) and 799 (Kita-Yamato-Trough) are characterized by high organic carbon contents of up to 6%; the organic matter is a mixture between marine and terrigenous material. Dominant mechanisms controlling (marine) organic carbon enrichments are probably high-surface water productivity and increased preservations rates under anoxic deep-water conditions. In the lower Pliocene sediments at Site 798 and the Miocene to Quaternary sediments at Site 799, rapid burial of organic carbon in turbidites may have occurred episodically. Distinct cycles of dark laminated sediments with organic carbon values of more than 5% and light bioturbated to homogenous sediments with lower organic carbon contents indicate dramatic shortterm paleoceanographic variations. More detailed records of accumulation rates of marine and terrigenous organic carbon and biogenic opal as well as a detailed oxygen isotope stratigraphy are required for a more precise reconstruction of the environmental history of the Sea of Japan through late Cenozoic time.
    Pages: Online-Ressource (217 Seiten)
    ISBN: 9783540463078
    Language: English
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  • 9
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    Berlin ; Heidelberg : Springer
    Description / Table of Contents: INTRODUCTION Evaporites may form in a spectrum of environments from continental sabkha (playa) to deep basins (see Kendall 1978 a, b, Schreiber 1978, 1986, Friedman and Krumbein 1985, for review). In the last two decades, many ancient evaporite basins have been interpreted using the sabkha model and the deep desiccated basin model, the former not excluding the latter. However, growing evidence has been gathered indicating that most evaporites are formed in subaqueous environments, so that it cannot be reasonably expected that one depositional model alone will explain the entire basin fill. The chapters in this volume discuss characteristic examples of evaporite basins, mostly of moderate size. Aspects of a saline giant, the Zechstein basin of Central and NW Europe, have been considered in Volume 10 of "Lecture Notes in Earth Sciences"...
    Pages: Online-Ressource (188 Seiten)
    ISBN: 9783540186793
    Language: English
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  • 10
    Description / Table of Contents: INTRODUCTION Ecometry concerns measurements and interpretation of ecological data and relationships between data. It deals with most matters involved in the scientific aspects of the representativity and information value of samples and does not, in fact, concern statistical methods. In particular, ecometry can be regarded as an approach to obtain so-called load models and load diagrammes (effect-dose-sensitivity diagrammes), which are one of the aims/final products in aquatic environmental consequence analysis (H~- kanson, 1990; all these terms will be explained later on). This publication is meant to demonstrate what can and cannot be done using ecometric approaches. It must be emphasized at the outset that the main intention here is not to provide new radioecological knowledge on how Cs-137 is dispersed in aquatic ecosystems after the Chernobyl accident and is taken up in fish, but to use Cs-137 as a type substance and pike as a biological indicator to go through methods which should also apply to other types of environmentally hazardous substances (it could just as well have been substance X in ecosystem Y). As a secondary effect, we may also learn something about Cs-137. Several terms and methods, which have not been used earlier in the aquatic environmental sciences, e.g., ecometric analysis and dynamic modelling using moderators, will be discussed and defined...
    Pages: Online-Ressource (158 Seiten)
    ISBN: 9783540539971
    Language: English
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