ALBERT

Beschreibung / Inhaltsverzeichnis: Especially due to the increasing environmental problems there is a need to collect as many data as possible in the upper atmosphere. This book serves as a general multidisciplinary guide and introduction for a more effective use of the large amount of now available data from the Earth's atmosphere. It also shows the problems of the use of large amounts of time series data - for basic science as well as for environmental monitoring - and the related information systems. The book is aimed for scientists and students interested in the Earth's atmosphere which is vital for the understanding of environmental changes in the global system Earth

Beschreibung / Inhaltsverzeichnis: I. Introduction --- 1. Computer Experiments of Space Plasmas --- II. Simulation Techniques --- 2. KEMPO1 --- 3. TRISTAN --- 4. MACRO-EM --- 5. HYBRID CODES --- 6. TWO-DIMENSIONAL MHD CODE --- 7. HIGH-PRECISION MHD SIMULATION --- 8. TUTORIAL FOR UNIX OPERATIONS --- III. Simulation Software --- 9. KEMPO1 --- 10. TRISTAN --- 11. MACROEM --- 12. HYBRID1 --- 13. MHD2 --- 14. WAVE

Beschreibung / Inhaltsverzeichnis: 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.

Beschreibung / Inhaltsverzeichnis: 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.

Beschreibung / Inhaltsverzeichnis: The subject of the book is an indepth description of the theory and mathematical models behind the application of the Global Positioning System in geodesy and geodynamics. The text has been prepared by leading experts in the field, contributing their particular points of view. Unlike a collection of disjoint papers, the text provides a continous flow of ideas and developments. The mathematical models for GPS measurements are developed in the first half of the book, followed by the description of GPS solutions for geodetic applications on local, regional and global scales.

Beschreibung / Inhaltsverzeichnis: Induced seismic events are of high scientific and economic significance. They are the result of human activities interacting with regional and local tectonics, changing the local crustal stress state by mining, extraction of rock masses, injection of fluids into the rock massif, and by changing the surface loading and pore pressure state near large reservoirs. Within Europe the study of induced seismic events has a long tradition and international scientific organizations have actively stimulated the co-operation in this field. During its General Assembly in September 1994, the European Seismological Society organized the symposium "Induced Seismic Events". The focus of this symposium was concentrated on induced events in central and eastern Europe, as well as in the former Soviet Union. The major contributions to the symposium, and also some Chinese, Canadian, and South African results are presented here. Case studies as well as data analyses and methodological studies are included. Seismologists and specialists working in the field of geohazard prevention will find much information in this volume that is pertinent to their work.

Beschreibung / Inhaltsverzeichnis: PREFACE Following the economical and social development of the local communities, mountain regions of temperate climates are increasingly becoming the site of valuable infrastructures and important urban and industrial settlements. As the catastrophic events of last years in the European Alps have clearly shown, the vulnerability of these territories has correspondingly increased, in terms of both property damage and losses of human life. Until recently, the hydraulic scientific community has paid little attention to mountain watersheds, except perhaps during the period if the hydropower development. Nevertheless attention was then focused on problems and methodologies somewhat different from the issues of actual environmental concern. More recently, however, hydraulic engineers have joined their colleagues from forest and rural engineering, who have traditionally dealt with erosion control in mountain areas, to bring in their own methodology, already experienced in lowland rivers. At the same time, academic people focused an interest in some phenomena, like massive transport, which is typical of mountain environment. To bring together all these contributions and to make the state of the art of the mountain river science (oropotamology) and technology, an International Workshop was called at the University of Trent (Italy), on October 1989, under the sponsorship of Fluvial Hydraulic Section of the IAHR. Three main topics have been recognized as particularly relevant from the point of view of both research and professivnal people: a) Hydrodynamics of steep channels and local scale process; b) Sediment movement and sediment training, with special emphasis on massive transport; c) Particular features of sediment transport related to non-uniform grain-size. However, as it is the case in these circumstances, the contest of several contributions often spread over more than one topic. In the following Introduction to papers, the three topics were split into 11 Sections, each one devoted to a more particular aspect recurrently addressed during the discussion. The same paper, thus, may be mentioned in different Sections of the Introduction.

Beschreibung / Inhaltsverzeichnis: PREFACE The objective of this book is to introduce the practitioner as well as the more theoretically interested reader into the integration problem of spatial information for Geo-lnformation Syslems. Former Get-Information Systems are restricted to 2D space. They realize the integration of spatial information by a conversion of vector and raster representations. This, however. leads to conceptual difficulties because of the two totally different paradigms. Furthermore, the internal topology of the get-objects is not considered. In recent years the processing of 3D information has played a growing role in Get-Information Systems. For example, planning processes for environmental protection or city planning are dependent on 3D data. The integration of spatial reformation will become even more impoaant in the 3D context and with the development of a new generation of open GISs. This book is intended to respond to some of these requirements. It presents a model for the integration of spatial information for 3D Geo-lnformation Systems (3D-GISs). As a precondition for the integration of spatial information, the integration of different spatial representations is emphasized. The model is based on a three-level notion of space that likewise includes the geometry, metrics and the topology of get-objects. The so called extended complex (e-complex) is introduced as a kernel of the model. Its internal basic geometries are the point, the line, the triangle and the tetrahedron. It is shown how a convex e-complex (ce-complex) is generated by the construction of the convex hull and the "'filling" of lines, triangles and tetrahedra, respectively. As we know from computer geometry, this results in substantially simpler geometric algorithms. Additionally, the algorithms gain by the explicit utilization of the topology of the ce-complex. This book also builds a bridge from the GIS to the object-oriented database technology, which will likely become a key technology for the development of a new generation of open Geo-lnformation Systems. In the so-called GEtmodel kernel "building blocks" are introduced that s~mplify the development of software architectures for geo-applications. A geological application in the Lower Rhine Basin shows the practical use of the introduced geometric and topological representation for a 3D-GIS...

Beschreibung / Inhaltsverzeichnis: Pages 1-13 / Maars of the Westeifel, Germany / G. Büchel --- Pages 15-60 / Syn- and post-eruptive mechanism of the Alaskan Ukinrek Maars in 1977 / G. Büchel, V. Lorenz --- Pages 61-80 / Maars and maar lakes of the Westeifel Volcanic Field / Jörg F. W. Negendank, Bernd Zolitschka --- Pages 81-94 / Maars of northern Auvergne (Massif Central, France): State of knowledge / E. Juvigné, G. Camus, A. de Goër de Herve --- Pages 95-107 / Palaeoenvironmental investigations on long sediment cores from volcanic lakes of Lazio (central Italy)—An overview / Maria Follieri, Donatella Magri, Biancamaria Narcisi --- Pages 109-116 / Geophysical mapping of organic sediments / Stefan Wende, Reinhard Kirsch --- Pages 117-118 / Preliminary uniboom survey of the Monticchio Lakes (southern Italy) / A. Stefanon --- Pages 119-128 / Sonar investigations in the Laghi di Monticchio (Mt. Vúlture, Italy) / Ralph B. Hansen --- Pages 129-148 / Climatic and tectonic effects on sedimentation in central Italian volcano lakes (Latium)—Implications from high resolution seismic profiles / F. Niessen, A. Lami, P. Guilizzoni --- Pages 149-161 / Sediments and basin analysis of Lake Schalkenmehrener Maar / T. Heinz, B. Rein, J. F. W. Negendank --- Pages 163-171 / Organic carbon contents of sediments from Lake Schalkenmehrener Maar: A paleoclimate indicator / B. Rein, J. F. W. Negendank --- Pages 173-194 / Basin analysis for selected time-frames using sedimentation rates in Lake Meerfelder Maar (Westeifel FRG) / F. Wegner, J. F. W. Negendank --- Pages 195-208 / Turbidites in the sediments of Lake Meerfelder Maar (Germany) and the explanation of suspension sediments / D. Drohmann, J. F. W. Negendank --- Pages 209-222 / Paleoclimate reconstruction at the Pleistocene/Holocene transition—A varve dated microstratigraphic record from Lake Meerfelder Maar (Westeifel, Germany) / D. Poth, J. F. W. Negendank --- Pages 223-235 / Paleoenvironmental reconstruction of the Late- and Postglacial sedimentary record of Lake Weinfelder Maar / A. Brauer, J. F. W. Negendank --- Pages 237-275 / Sedimentology and paleoenvironment from the Maar Lac du Bouchet for the last climatic cycle, 0-120,000 years (Massif Central, France) / Elisabeth Truze, Kerry Kelts --- Pages 277-288 / Lago Grande di Monticchio (southern Italy) a high resolution sedimentary record of the last 70,000 years / Bernd Zolitschka, Jörg F. W. Negendank --- Pages 289-304 / A multidisciplinary study of the Vico Maar sequence (Latium, Italy): Part of the last cycle in the Mediterranean area. Preliminary results / P. Francus, S. Leroy, I. Mergeai, G. Seret, G. Wansard --- Pages 305-316 / Environmental geology and geochemistry of lake sediments (Holzmaar, Eifwl, Germany) / B. G. Lottermoser, R. Oberhänsli, B. Zolitschka, J. F. W. Negendank, U. Schütz… --- Pages 317-332 / Geochemistry of Lago Grande di Monticchio, S. Italy / C. Robinson, G. B. Shimmield, K. M. Creer --- Pages 333-348 / Tephrochronology of core C from Lago Grande di Monticchio / Anthony J. Newton, Andrew J. Dugmore --- Pages 349-365 / A palaeomagnetic study of maar-lake sediments from the Westeifel / B. Haverkamp, Th. Beuker --- Pages 367-376 / Preliminary 50m palaeomagnetic records from Lac du Bouchet, Haute Loire, France / T. Williams, K. M. Creer, N. Thouveny --- Pages 377-392 / Palaeomagnetic investigations of Lago Grande di Monticchio, southern Italy / Ian Turton --- Pages 393-420 / Late-Glacial/Holocene changes of the climatic and trophic conditions in three Eifel maar lakes, as indicated by faunal remains. I. Cladocera / Wolfgang Hofmann --- Pages 421-433 / Late-glacial/Holocene changes of the climatic and trophic conditions in three Eifel maar lakes, as indicated by faunal remains. II. Chironomidae (Diptera) / Wolfgang Hofmann --- Pages 435-439 / Ostracoda (Crustacea) and trichoptera (Insecta) from Late-and Postglacial sediments of some European maar lakes / Burkhard W. Scharf --- Pages 441-446 / Oligocence dinoflagellate-cysts in Quaternary freshwater sediments of Eifel maars / H. Weiler --- Pages 447-465 / Tertiary maars of the Hocheifel Volcanic Field, Germany / G. Büchel, M. Pirrung --- Pages 467-476 / Some aspects of Cenozoic maar sediments in Europe: the source-rock potential and their exceptionally good fossil preservation / W. Zimmerle --- Pages 477-484 / Palaeoecological implications from the sedimentary record of a subtropical maar lake (Eocene Eckfelder Maar; Germany) / Bernd Zolitschka --- Pages 485-489 / Arthropods from the Eocene Eckfelder Maar (Eifel, Germany) as a source for paleoecological information / H. Lutz --- Pages 491-497 / Flowers from the Middle Eocene of Eckfeld (Eifel, Germany)— First results / H. Frankenhäuser, V. Wilde --- Pages 499-503 / Initial results on the importance of a flora from the Middle Eocene of Eckfeld (Eifel, W.-Germany) / V. Wilde, H. Frankenhäuser --- Pages 505-509 / International Maar Deep Drilling Project (MDDP) a challenge for earth sciences? / Jörg F. W. Negendank, Bernd Zolitschka

Beschreibung / Inhaltsverzeichnis: PREFACE This book represents the first attempt in three decades to marshall out available information on the regional geology of Africa for advanced undergraduates and beginning graduate students. Geologic education in African universities is severely hampered by the lack of a textbook on African regional geology. This situation is greatly exacerbated by the inability of most African universities to purchase reference books and maintain journal subscriptions. Besides, geologic information about Africa is so widely dispersed that a balanced and comprehensive course content on Africa is beyond the routine preparation of lecture notes by university teachers. Since geology is a universal subject and Africa is one of the largest landmasses on Earth with one of the longest continuous records of Earth history, there is no doubt that geologic education in other parts of the world will benefit from a comprehensive presentation of African geologic case histories. The scope of this text also addresses the need of the professional geologist, who may require some general or background information about an unfamiliar African geologic region or age interval. Africa occupies a central position in the world's mineral raw materials trade. Because of its enormous extent and great geologic age, the diversity and size of Africa's mineral endowment is unparalleled. Africa is the leading source of gold, diamond, uranium, and dominates the world's supply of strategic minerals such as chromium, manganese, cobalt, and platinum. Consequently, African nations from Algeria to Zimbabwe depend solely on mineral exports for economic survival. The geologic factors which govern economic mineral deposits are stressed in this text. The geological history of Africa spans 3.8 billion years, a record that is unique both in duration and continuity. Few other parts of our planet match the plethora of geologic phenomena and processes that are displayed in the African continent. From the various stages of crustal evolution decipherable from the Archean of southern Africa, through the plate tectonics scenarios in the ubiquitous Late Proterozoic-Early Paleozoic Pan-African mobile belts and in the Hercynian and Alpine orogenies of northwest Africa, to the East African Rift Valley, Africa is replete with excellent examples and problems for a course on regional tectonics. Teachers of igneous and metamorphic petrology can hardly ignore Africa's anorogenic magmatism (e.g.. layered ultramafic intrusives such as the Great Dyke and the Bushveld Complex; the Tete gabbro-anorthosite pluton; alkaline complexes; basaltic volcanism), or tantalizing highgrade metamorphic terranes such as the Limpopo belt, the Namaqua mobile belt, and the Mozambique belt. From the extensive Precambrian supracrustal sequences throughout the continent with enormous thicknesses of sedimentary rocks that have hardly been deformed or metamorphosed, to the stratigraphic evolution of Africa's present-day passive continental margin, there is a complete spectrum of facies models upon which to base a course on basin analysis and stratigraphy. To maintain its integrity a course on historical geology anywhere in the world must address the theory of Continental Drift beyond invoking past continuities between West Africa and South America. Past connections between West Africa and eastern North America must equally be explored, so also connections between northeast Africa and Arabia, and the paleogeography of southern Gondwana where Africa occupied centre stage. The Precambrian fossil record, the transitions from reptiles to the earliest mammals and dinosaurs, and the evolution of Man are among Africa's unique contributions to the history of life and the story of organic evolution. Although it lies today in the tropics Africa was the theatre of the Earth's most-spectacular glaciations. Even after the scene of continental glaciation had shifted to the northern continents only lately during the Pleistocene, Africa still witnessed spectacular climatic fluctuations during the Quaternary. Certainly students of archeology and paleoanthropology cannot overlook the Quaternary paleoenvironmental record of the Olduvai Gorge in Tanzania, the Lake Turkana basin in Kenya, the Nile valley, the Sahara, and southern Africa. But since African examples have already been cited in standard geologic textbook, I have often been asked why it has become necessary to revive the idea of a full-length textbook on African geology, 30 years after this idea was abandoned by the geologic community. My simple answer, as already stated, is that the wealth of available geologic information about Africa is so enormous and fascinating, but so diffuse, that an attempt must be made to assemble and pass on this knowledge.

Beschreibung / Inhaltsverzeichnis: PREFACE Sedimentation as a Three-Component System describes the most common styles of deposition in marine environments as they relate to sediment composition. Three components, organic matter, carbonate, and siliciclastic sediment, may settle concurrently, but at different rates, intermixing on the sea floor to form a particular sediment composition. A change in the flux of one component is capable of relatively diluting or concentrating the other two components, which can be expressed in the characteristic ratio of organic carbon to carbonate in the resulting sediment. The basic concept of this book is to address organic carbon-carbonate associations in terms of depositional inputs and time spans. In addition, the three-component system describes organic carbon changes related to major facies transitions. Examples include models of the genesis of carbonaceous sediments, with their various laminated to bioturbated lithotypes, and numerical organic carbon prediction. I hope that this book will encourage stimulating discussions and promote a new approach to quantitative stratigraphy...

Beschreibung / Inhaltsverzeichnis: 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.

Beschreibung / Inhaltsverzeichnis: 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.

Beschreibung / Inhaltsverzeichnis: 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...

Beschreibung / Inhaltsverzeichnis: INTRODUCTION The study is essentially empirical, since it portrays and appraises two different water management systems, and relates them to one another. Yet the analysis has also been made with definite research aims in mind. Its focus has been narrowed down to the environmental assessment of urban water management systems in arid and semi-arid regions, especially with an eye to deal with information problems in the Developing World. The study addresses a set of very critical issues of global concern, and, thus, delineates a crucial topic for international research. The fact that a wide range of critical issues usually complicates and aggravates the given problem setting provides the comparative analysis with a special practical incentive to explore the opportunities for joint strategies and comprehensive solutions. However, the complexities involved between water management and the environment and the relative lack of a joint theory in that field pose certain difficulties to such an undertaking. In order to fully appreciate the underlying purpose of the study and the scope of its implications, the various facets of the problem setting and the essential ingredients of the general line of approach have first to be unravelled and expounded at some length. Above all, it needs to be shown how these facets combine to produce the complex, burning issues which in turn seem to, both in theory and practice, require correspondingly intricate, strategic approaches for their solutions...

Beschreibung / Inhaltsverzeichnis: PREFACE The ocean has always been reluctant to reveal its secrets. Its size and the inaccessibility of its deeper regions have made their safeguard a reasonably simple matter with the result that significant misconceptions persisted for many years. Two of the most widespread of these concerned the featureless nature of the sea floor and the silence of the deep ocean. Underwater acoustics has played a key role in discrediting both and in so doing introduced new and exciting developments in oceanography and geophysics. In the years following World War II, echosounders and subbottom profilers based on new active sonar technology, revealed the true nature of the seafloor topography and led to the major advances represented by plate tectonics. Research driven by the requirements of passive sonar, on the other hand, was to demonstrate that the sea was not silent but was characterised by a complex noise spectrum. Many individual mechanisms and sources ranging from man-made, biological and geophysical activity to the intrinsic noise of the sea itself were found to contribute to this spectrum. A major component, which is the subject of this book, was to remain unrecognised to underwater acoustics until noise measurements could be made effectively at very low frequencies, although its presence had been indicated by seismology long before these measurements were possible. By virtue of its geographical isolation in the Southern Ocean, New Zealand has provided an ideal environment for long-range propagation and ambient noise investigations and numerous studies have been reported. Our interest in the subject of this book was aroused initially in the course of one such experiment in 1966. For the first time it had been possible to extend the recording bandwidth to 1 Hz and the improved performance of this new system was anticipated eagerly. However the main purpose of the experiment was nearly aborted by the appearance of a new and unsuspected noise component at frequencies below 10 Hz. Due primarily to technical limitations in the equipment then available, a subsequent programme, designed to identify the properties and origin of the source more clearly, was not productive and was soon abandoned. An opportunity to revisit the problem arose some 10 years later, when the University of Auckland became involved in a major environmental study in support of the development of an offshore gas field in Cook Strait. The technology then available provided an opportunity to examine afresh the relationship between sea state and the seismo-acoustic response generated. An initial trim demonstrated the potential of the site. Accordingly a long-term programme, involving the parallel measurement of the oceanwave field and acoustic response, was undertaken in a series of student research theses. The data so gathered were of sufficiently high quality to ultimately establish wave-wave interactions as the source of the acoustic effects observed and to identify many of its characteristics. This result was soon to be confirmed by other studies. As the noise data accumulated, however, it became apparent that certain refinements to the theories describing the mechanism were required. Our attempts to provide these refinements have been reported in a number of contributions in recent years. The accounts of these and similar contributions by others have unfortunately appeared in the literature in a somewhat disjointed manner, with the result that the evolution of the subject has not been easy to follow. This book attempts to present a more coherent account of the subject and its development. Most of the early experimental and theoretical results from our group have arisen from two key Ph.D. theses, due to Dr. K.C. Ewans and Dr. C.Y. Wu. The painstaking and careful instrumentation development and data analysis provided by Dr. Ewans were critical to the definitive correlation which we were able to establish between wind field, seastate and the acoustic response so generated. Dr. Wu's thesis presented the first phase of our attempt at the resolution of certain key theoretical issues, which were identified in the course of the experimental programme. Both studies owe much to the support of Shell BP Todd Oil Services Ltd., acting for Maui Development Ltd., and to the University of Auckland. The support of the Electricity Corporation of New Zealand Ltd. during a later experimental investigation of the Southern Ocean wave field is also acknowledged...

Beschreibung / Inhaltsverzeichnis: INTRODUCTION --- Shock Compression Chemistry of materials, Y. Horie and A. B. Sawaoka, pp. 3-22 --- 1.1 The Nature of Shock Waves, pp. 3-5 --- 1.2 Compaction of Powders and Shock Activation, pp. 6-9 --- 1.3 First-Order Phase Transitions and Chemical Reactions, pp. 10-12 --- 1.4 Time Scales and Interactions of Basic Mechanisms, p. 12 --- 1.4.1 Shock propagation in a particle assemblage, p. 12 --- 1.4.2 Energy localization, pp. 12-13 --- 1.4.3 Thermal relaxation of hot spots, p. 14 --- 1.4.4 Mass diffusion in solids, p. 14 --- 1.4.5 Kinetic constants, pp. 14-16 --- 1.5 Some Roles of Shock Compression Techniques in Material Sciences Study, p. 16 --- 1.5.1 Shock compression technique as a tool of high pressure production, p. 16 --- 1.5.2 Appearance of diamond anvil-type high-pressure apparatus, pp. 16-18 --- 1.5.3 New roles of shock compression technology as a unique method of very high temperature production, pp. 18-19 --- 1.5.4 Development of conventional hypervelocity impact techniques for precise measurement of materials under shock compression, pp. 19-21 --- FUNDAMENTALS OF SHOCK WAVE PROPAGATION --- Shock Compression Chemistry of materials, Y. Horie and A. B. Sawaoka, pp. 23-78 --- 2.1 Hydrodynamic Jump Conditions and the Hugoniot Curve, pp. 23-32 --- 2.2 Shock Transition in Hydrodynamic Solids, pp. 32-42 --- 2.3 Non-Hydrostatic Deformation of Solids, p. 42 --- 2.3.1 Elastic-ideally-plastic solids, pp. 42-53 --- 2.3.2 Experimental observations of elastic-plastic behavior, pp. 53-56 --- 2.4 Wave-body interactions, pp. 56-57 --- 2.4.1 Preliminaries, pp. 57-60 --- 2.4.2 Planar impact of similar and dissimilar bodies, pp. 60-61 --- 2.4.3 Shock wave interaction with material boundaries, pp. 61-64 --- 2.4.4 Wave-wave interactions, pp. 65-66 --- 2.4.5 Detonation wave and interaction with a solid surface, pp. 66-77 --- SHOCK COMPRESSION TECHNOLOGY --- Shock Compression Chemistry of materials, Y. Horie and A. B. Sawaoka, pp. 79-115 --- 3.1 Gun Techniques, p. 80 --- 3.1.1 Single stage gun, p. 80 --- 3.1.2 Conventional two stage light gas gun, pp. 80-83 --- 3.1.3 Velocity measurement of projectile, p. 83 --- 3.1.4 Magnetoflyer method, pp. 83-84 --- 3.1.5 CW x-ray velocity meter, pp. 84-86 --- 3.1.6 Measurement of interior projectile motion, pp. 86-87 --- 3.1.7 Recovery experiments, pp. 87-89 --- 3.2 Explosive Techniques, p. 89 --- 3.2.1 Plane shock wave generation and recovery fixture, pp. 89-91 --- 3.2.2 Numerical simulaation of shock compression in the recovery capsule, pp. 91-94 --- 3.2.3 Cylindrical recovery fixture, pp. 94-95 --- 3.3 In-situ Measurements, p. 95 --- 3.3.1 Manganin pressure gauge, pp. 95-98 --- 3.3.2 Particle velocity gauge, pp. 99-100 --- 3.3.3 Observations of multiple shock reverberations by using a manganin pressure gauge and particle velocity gauge, pp. 100-106 --- 3.3.4 Shock temperature measurement, pp. 106-111 --- 3.3.5 Copper-Constantan thermocouple as a temperature and pressure gauge, pp. 111-113 --- THERMOMECHANICS OF POWDER COMPACTION AND MASS MIXING --- Shock Compression Chemistry of materials, Y. Horie and A. B. Sawaoka, pp. 117-170 --- 4.1 A One Dimensional Particulate Model, pp. 117-123 --- 4.2 Continuum Models, p. 123 --- 4.2.1 Hydrodynamic models, pp. 124-141 --- 4.2.2 Continuum plasticity theory, pp. 141-148 --- 4.2.3 Application, pp. 148-154 --- 4.3 Particle Bonding and Heterogeneous Processes, pp. 154-160 --- 4.4 Mass Mixing, pp. 160-169 --- THERMOCHEMISTRY OF HETEROGENEOUS MIXTURES --- Shock Compression Chemistry of materials, Y. Horie and A. B. Sawaoka, pp. 171-225 --- 5.1 Thermodynamic Functions of Heterogeneous Mixtures, pp. 172-187 --- 5.2 Analytical Equations of State, pp. 187-191 --- 5.3 Hugoniots of Inert Mixtures, p. 191 --- 5.3.1 Thermodynamically equilibrium models, pp. 191-197 --- 5.3.2 Mechanical models, pp. 197-199 --- 5.4 First-Order Phase Transitions, pp. 199-206 --- 5.5 Chemical Equilibria, pp. 206-212 --- 5.6 Reaction Kinetics, p. 212 --- 5.6.1 Rate equations, pp. 212-214 --- 5.6.2 Nucleation, pp. 214-216 --- 5.6.3 Growth, pp. 216-217 --- 5.6.4 Pressure effects, pp. 217-218 --- 5.7 Shock-Induced Reactions in Powder Mixtures, pp. 218-224 --- HYDRODYNAMICAL CALCULATIONS --- Shock Compression Chemistry of materials, Y. Horie and A. B. Sawaoka, pp. 227-276 --- 6.1 Conservation Equations of Continuum Flow, pp. 227-228 --- 6.1.1 Mass conservation, pp. 228-230 --- 6.1.2 Conservation of linear momentum, pp. 230-231 --- 6.1.3 Enegy conservation, pp. 231-234 --- 6.2 Constitutive Modeling of Inorganic Shock Chemistry, pp. 234-235 --- 6.2.1 VIR model, pp. 235-239 --- 6.2.2 Pore collapse, p. 239 --- 6.2.3 Chemical kinetics, pp. 239-240 --- 6.2.4 Computational constitutive reactions, pp. 240-245 --- 6.3 Applications of the VIR Model, p. 245 --- 6.3.1 Shock wave profiles in Ni/Al powder mixtures, pp. 245-250 --- 6.3.2 Compaction of diamond with Si and graphite, pp. 250-257 --- 6.4 Continuum Mixture Theory and the VIR Model, p. 257 --- 6.4.1 Continuum mixture theory, pp. 257-263 --- 6.4.2 Derivation of the VIR model using the CMT, pp. 263-269 --- 6.4.3 A model of heterogeneous flow, pp. 269-275 --- SHOCK CONDITIONING AND PROCESSING OF CERAMICS --- Shock Compression Chemistry of materials, Y. Horie and A. B. Sawaoka, pp. 277-360 --- 7.1 Shock Conditioning of Powder of Inorganic Materials, p. 227 --- 7.1.1 Brief review of shock conditioning studies, p. 227 --- 7.1.2 Aluminum oxide powder, pp. 277-281 --- 7.2 Shock Synthesis of Inorganic Materials, p. 281 --- 7.2.1 Shock synthesis studies, p. 281 --- 7.2.2 High dense forms of carbon, pp. 281-285 --- 7.2.3 High dense forms of boron nitride, pp. 285-287 --- 7.2.4 Shock treatment of boron nitride powders, pp. 287-301 --- 7.3 Shock Consolidation of Ceramic Powders, p. 301 --- 7.3.1 Why non-oxide ceramics?, pp. 301-302 --- 7.3.2 Dynamic consolidation of SiC powders, pp. 302-304 --- 7.3.3 Approach to the fabrication of crack free compacts, pp. 304-305 --- 7.3.4 Shock consolidation of SiC powder utilizing post shock heating by exothermic reaction, pp. 305-310 --- 7.4 Dynamic Compaction of Zinc Blende Type Boron Nitride and Diamond Powders, p. 310 --- 7.4.1 Background, pp. 310-311 --- 7.4.2 Cubic boron nitride, pp. 311-318 --- 7.4.3 Diamond, pp. 318-326 --- 7.4.4 Diamond composites obtained by utilizzing exothermic chemical reaction, pp. 326-332 --- 7.5 Very High Pressure Sintering of Shock Treated Powders, pp. 332-334 --- 7.5.1 Silicon nitride, pp. 334-336 --- 7.5.2 w-BN, pp. 336-346 --- 7.6 Rapid Condensation of High Temperature Ultrasupersaturated Gas, p. 346 --- 7.6.1 Silicon nitride, pp. 346-352 --- 7.6.2 Carbon, pp. 352-357

Beschreibung / Inhaltsverzeichnis: Geodynamics concerns the dynamics of the earth's global motion, of the earth's interior motion and its interaction with surface features, together with the mechanical processes in the deformation and rupture of geological structures. Its final object is to determine the driving mechanism of these motions. It is highly interdisciplinary. In providing the basic geological, geophysical infromation required for a comprehensive mechanical analysis, there are also many mechanical problems involved, which means the problem is coupled intricately with geophysics, rock mechanics, seismology, structural geology, etc. This is Part II of the Proceedings of an IUTAM/IASPEI Symposium on Mechanics Problems in Geodynamics held in Beijing, September 1994. It discusses different aspects of mechanics problems in geodynamics involving the earth's rotation, tectonic analyses of various parts of the world, mineral physics and flow in the mantle, seismic source studies and wave propagation and application of the DDA method in tectonic analysis.

Beschreibung / Inhaltsverzeichnis: The special issue contains contributions presented at the international workshop Seismic waves in laterally inhomo- geneous media IV, which was held at the Castle of Trest, Czech Republic, May 22-27, 1995. The workshop, which was attended by about 100 seismologists from more than 10 countries, was devoted mainly to the current state of theoretical and computational means of study of seismic wave propagation in complex structures. The special issue can be of interest for theoretical, global and explorational seismologists. The first part contains papers dealing with the study and the use of various methods of solving forward and inverse problems in complicated structures. Among other methods, discrete-wave number method, the finite-difference method, the edge-wave supperposition method and the ray method are studied and used. Most papers contained in the second part are related to the ray method. The most important topics are two-point ray tracing, grid calculations of travel times and amplitudes and seismic wave propagation in anisotropic media.

Beschreibung / Inhaltsverzeichnis: INTRODUCTION The International Summer School of Theoretical Geodesy on Satellite Altimetry in Geodesy and Oceanography was held in Trieste (Italy) from May 25 to June 6, igg2. It was organized by Prof. R. Rummel of the Delft University of Technology and by Prof. F. Sansò of the Politecnico di Milano and was attended by 63 participants and 7 lecturers from 17 countries. The School was hosted by the International Centre of Theoretical Physics of Trieste. Satellite altimetry provides a lot of data that require more and more sophisticated models in order to be interpreted and exploited. One of the main problems related to the practical treatment of the data can be summarized as follows: oceanographers would like to ask geodesists to compute precise orbits and a precise geoid in order to put into evidence the Sea Surface Topography that can be interpreted as an oceanographic signal related to currents and to several physical parameters; on the other hand, geodesists would like to ask oceanographers to a-priori determine the Sea Surface Topography, in order to be able to extract from the altimeter data the geoid and the orbit errors to be used in the gravity field modelling. The solution to this dilemma can only be found in a cooperative frame. An integrated model to be used for a single-step treatment of altimetry is probably far to be defined, so at present geodesists and oceanographers must cooperate to obtain step-wise and iterative modelling of the gravity field and of the oceanographic phenomena. This is precisely the reason why the school on Satellite Altimetry was organized on an interdisciplinary basis...

Beschreibung / Inhaltsverzeichnis: PREFACE Some of the major ecological and social problems of the present and future are the production, treatment, and disposal of anthropogenic wastes. Iaais is equally true for sparsely and densely populated industrial areas, including large countries in which sites for waste disposal would seem to be readily available. Especially nonradioactive hazardous wastes with their long-term toxicity need to be isolated from the biosphere just as effectively as radioactive substances. The long-term safety required of waste disposal sites can only be assured under specific geological and mineralogical conditions in certain parts of the lithosphere (underground repositories). The subjects related to the production, avoidance, treatment, and disposal of anthropogenic wastes cover a range of knowledge encompassing the natural sciences, engineering, medicine, and law. This work presents some fundamental situations and problems conceming the disposal of toxic hazardous wastes which have been dealt with in several research projects. The individual chapters are related scientifically. Long-term, effective solutions to our waste problems can only be found when interrelationships and possible future developments are considered. Only the current status of this rapidly developing field can be discussed here. The individual chapters contain scientifically founded data and observations. Other aspects for which there are still controversial opinions and arguments are also discussed, which should stimulate further thought. Further developments and scientific advances can only be achieved by constantly challenging previous theories, and not through static observation and narrow-mindedness. The most extensive quantification possible of the problems related to disposal of hazardous wastes is an essential aim of our work. This not only involves calculating the volume of waste and available repository space, but also compiling data on the long-term effects and the safe, long-term isolation of anthropogenic wastes from the biosphere. A simple description of conditions and processes without using concrete data, which is still widespread, is rejected since it frequently leads to pure speculation. The scientific fundamentals and results presented in this work are of general validity for many questions concerning waste disposal. One example is the amount of waste produced annually in Germany, in which toxic, hazardous wastes play a major role. FoIlowing this train of thought, available data are used to show how limited the possibilities are for the long-term safe underground deposition of hazardous wastes with respect to the current quantities of waste. Of utmost importance is information on the 10ng-term effects of toxic wastes, as well as criteria which have to be considered with respect to the long-term safe deposition of hazardous waste. The natural chemical cycles and material transport in the various zones of the earth are the focus of interest here. They are the scientific basis for assessing every repository for anthropogenic wastes in geological systems. Therefore the significance of material transport and geochemical cycles is emphasized regarding all questions concerning the long-term safety of repositories on the earth's surface and in the lithosphere. Thus, our concept for the scientific evaluation of the long-term safety of underground repositories in geological systems differs from all other models presently under discussion in Germany. In this work, marine evaporites are discussed with respect to the underground deposition of hazardous wastes and the long-term safety of underground repositories in salt rocks. The isolation of hazardous materials from the biosphere can above all be influenced by fluid phases. Fluid phases can mobilize and transport hazardous materials through rocks in the biosphere. This is true, without exception, for all magmatic, sedimentary, and metamorphic rocks, and for marine evaporites, too! In Germany evaporites have commonly been considered to be completely impermeable with respect to fluid phases (solutions and gases). This erroneous view stems from a complete lack of knowledge or misestimation of the dynamic evolution of the composition of evaporite bodies. Unfortunately, this is still true today for parts of some state agencies which deal with repositories. However, all observations of evaporite bodies made over the last more than 100 years have clearly shown that under certain conditions fluid and gaseous components are mobile in evaporites as well. Solutions in marine evaporites have been the object of personal interest and scientific research of A.G. Herrmann for 40 years. The occurrence and formation of salt solutions in the various salt mining districts of Germany are presently being restudied and reevaluated on an extended scientific basis (e.g., v. BORSTEL 1992). A presentation of the current knowledge on salt solutions is beyond the scope of this publication. However, in the interest of continuing research a research project proposed by A.G. Herrmann (1987b) will be introduced here. The direct quantitative analysis of the chemical composition (quatemary and quinary systems) of small fluid inclusions in rocks of the salt deposits of Hessen and Niedersachsen are the primary focus of this project. Information important to fundamental research on the formation and alteration of salt rocks and on the long-term safety of underground repositories should be gained from these studies (e.g., HERRMANN & v. BORSTEL 1991). In addition to salt solutions, gases are also fluid components which occur in practically all marine evaporite deposits. Hence, both salt solutions and gases must be carefully considered when planning underground repositories in an evaporite body and evaluating their long-term safety. This publication contains an up-to-date overview of the gas occurrences in the marine evaporites of Central Europe. Despite previous studies, there is still a considerable deficit in scientific information regarding the distribution and formation of gases in the evaporites occurring in Germany. A detailed research program on the geochemical relationships involving the formation of evaporites and gases will draw attention to this situation. One aspect must be emphasized in the planning and construction of repositories for anthropogenic wastes: their long-term safety. This publication deals precisely with this subject, and in Part III of this work we will present the concept that we have developed. This concept is based on the fact that evaporite bodies are subject to a dynamic evolution and that the chemical and mineralogical composition provides important information on the effect of fluid phases on salt rocks. Previous works contain the testing of methods and presented initial results using the Gorleben salt dome as an example. However, we are just at the beginning of our research project on the long-term safety of underground repositories (e.g., HERRMANN & KNIPPING 1989, HERRMANN 1992). The information contained in this publication is based on years of experience in evaporite research and underground repositories for anthropogenic wastes. Examples are presented which can be applied to similar situations and problems in other countries. Waste disposal is not just a national problem, it has long become an international one for all types of anthropogenic wastes...

Beschreibung / Inhaltsverzeichnis: Chapter 1. Primitive Solar Nebula --- Evolution of Magnetized Dense Clouds / T. Nakano, T. Nakamura, T. Terasawa, and Y. Sano / pp. 1-28 --- Molecular Outflows—Observational Signature for the Earliest Phase of Stellar Evolution— / Y. Fukui, A. Mizuno, H. Ogawa, and K. Kawabata / pp. 29-45 --- Observational Evidence of Transition between Protostellar Objects and T Tauri Stars / S. Sato / pp. 47-57 --- Jet Formation and Enhanced Accretion due to Magnetic Effects in Protostellar Objects / Y. Uchida / pp. 59-77 --- Shear Instability of the Solar Nebula / M. Sekiya, S. M. Miyama, and Y. Nakagawa / pp. 79-88 --- Magnetic Fossil of the Solar Nebula Observed in Meteorites / T. Nagata / pp. 89-103 --- Experimental Demonstration of Formations of Tetrataenite and Pyrrhotite / C. Kaito and Y. Saito / pp. 105-112 --- Synthesis of Carbonaceous and Siliceous Materials / A. Sakata and S. Wada / pp. 113-127 --- Chapter 2. Origin of Giant Planets --- Scenario of Formation Processes of the Giant Planets / H. Oya / pp. 129-134 --- Giant Planetary Systems—A Review— / H. Oya / pp. 135-193 --- Accumulation of Materials for the Formation of the Giant Planets—Ring Model under the Flow-out Motion of Disc Gas— / H. Oya / pp. 195-220 --- Nonlinear Evolution of the Accumulation Processes of the Material for Formation of the Giant Planets in the Primeval Solar System / H. Oya and M. Iizima / pp. 221-240 --- Simulation Studies on the Formation Processes of the Saturnian Ringlets / H. Oya, M. Miyauchi, T. Imai, and M. Iizima / pp. 241-164 --- Chapter 3. Origin of the Terrestrial Planets --- Elementary Processes in Planetary Accretion / K. Nakazawa, S. Ida, and K. Ohtsuki / pp. 265-280 --- Experimental Simulation of Collisions / A. Fujiwara, A. Nakamura, M. Kato, and Y. Takagi / pp. 281-295 --- Scaling Law on Impact Phenomena / H. Mizutani / pp. 297-317 --- Numerical Simulation of Planetary Growth / M. Hayakawa and H. Mizutani / pp. 319-340 --- Deformation of Porous Ice-Rock Mixtures and an Application to the Densification of Icy Satellites / N. Maeno, M. Arakawa, and J. Leliwa-Kopystynski / pp. 341-353 --- Chapter 4. Origin of Meteorites --- Precise Determination of the Age of Formation of Meteorites / K. Takahashi and A. Masuda / pp. 355-373 --- Chemical Differentiation during Collision and Accretion of Meteorite Parent Bodies / H. Takeda / pp. 375-394 --- Isotope Variations of Light Elements in Chondrites—Ion Microprobe Studies— / C. Uyeda, H. Nishimura, and J. Okano / pp. 395-408 --- Trace Element Fractionation during the Formation of Chondrules / N. Nakamura / pp. 409-425 --- Vaporization and Condensation of Chondritic Materials—Experimental Studies— / H. Nagahara, 1. Kushiro, and B. O. Mysen / pp. 427-446 --- Metamorphic Processes in New CI Carbonaceous Chondrites from Antarctica: Mineralogy and Petrology / K. Tomeoka / pp. 447-464 --- Evolution and Alteration Process of the CM Carbonaceous Chondrites / H. Kojima and K. Yanai / pp. 465-477 --- Structure and Chemistry of Carbon in Meteorites / T. Murae, H. Kagi, and A. Masuda / pp. 479-501 --- Chapter 5. Origin and Evolution of the Terrestrial Atmosphere --- 244Pu Fission Xe in the Mantle and Mantle Degassing Chronology / M. Ozima, S. Azuma, S. Zashu, and H. Hiyagon / pp. 503-517 --- The Noble Gases in the Venusian Atmosphere and the Fukutomi Chondrite / N. Takaoka / pp. 519-526 --- Formation of Atmospheres of Terrestrial Planets from Volatiles in Solid (Meteoritelike) Material / N. Sugiura / pp. 527-543 --- Early Evolution of the Terrestrial Planets: Accretion, Atmosphere Formation, and Thermal History / T. Matsui / pp. 545-559 --- Existence of Life and Creation of Atmospheric Environment / S. Moriyama / pp. 561-577 --- Chapter 6. Exploration of the Solar System—Halley Mission— --- Interaction of Plasma of Halley's Comet with the Solar Wind / H. Oya / pp. 579-614 --- Plasma Environment of Comet Hally Observed by Suisei / T. Terasawa and S. Takahashi / pp. 615-628 --- Modelling Study of the Cometary Ly α Brightness from a Time-varying H2O Source / O. Ashihara / pp. 629-643 --- Cometary Dust / T. Mukai / pp. 645-662 --- The Origin of Comets as Viewed from the Gaseous Composition / T. Yamamoto / pp. 663-677

Beschreibung / Inhaltsverzeichnis: INTRODUCTION "The geological history, as expressed by the stratigraphic column, is basically composed of cycles of sedimentation, stratification and magmatism which correlate with relative changes in sea level determined in turn by different types of crustal movements. The classical sequence of stages "transgression - inundation - differentiation - regression - emergence" is believed to reflect the deformation phases of a geotectonic cycle" (Wezel,1988: p.37). The concept of geotectonic cycle is fundamental in geology because it links tectonics with sedimentary processes. According to Wezel (1988) the geotectonic cycle is an expression of cyclic variations in the behavior of the crust; more precisely,it is a geodynamic response to the Earth's variations in the rate of rotation (Mörner,19869 Whyte,1977~ Carey,1976).Based on a global analysis of geotectonic data, synchronous episodes of intense global swelling, governed by cyclically ordered diastrophic processes, were identified (Wezel,1985;1988). The process leading to these swells was termed krikogenesis (Wezel, 1988).It basically consists of not steady, localized, migratory vertical movements linked to mantle diapirism and concentrated in single zones.The overlying crust adjusts itself to mantle motions induced by krikogenesis, with the formation of transient troughs and swells ('touche-de-piano' tectonics).This mechanism was individuated in several areas (Wezel,1988). The history of the Earth is described by six episodes that repeat in the same way in the course of geological time.Their duration progressively decreases:the first cycle has a duration of about 200 million years, the following,younger cycles lasted 150, 115, 65, A5 and 20 m.y. ...

Beschreibung / Inhaltsverzeichnis: INTRODUCTION Humic substances, comprise a class of biogenic, coloured, organic substances that are ubiquitous in soil, sediment and water. Originally, the occurrence and nature of humic substances were regarded as issues of primarily academic interest. This situation is now rapidly changing, and studies of humics have gained recognition as important contributions to environmental science. In particular it has been shown that humic substances, in several different ways can interact with biologically active substances, thereby modifying their environmental impact. Whereas the history of soil humus studies goes back to the 19th century, the awareness of aquatic humus is more recent. The brownish colour that, in many surface waters, shows the presence of substantial amounts of humic substances, was long considered to be a harmless phenomenon that did not call for detailed investigations. Hnmic waters had few known toxic effects, and the refractory character of hnmic substances indicated the they played a peripheral role in most biochemical processes. In fact, it was not until the mid 70's that aquatic humus was brought into focus in environmental science. The event trigging this was the discovery of the interaction between humic substances and chlorine used for disinfection of drinking water. Toxic substances, such as chloroform, were detected in all chlorinated waters, and humic substances were identified as the main precursors. The role of humics in the mobilization and subsequent transport of trace elements in the environment was recognized for the first time in the early 80's. This role was considered to be of particular importance in connection with geologic storage of high-level radioactive waste. In water with "normal" concentration levels of humic compounds, the speciation of e.g. the trivalent actinides, would be entirely dominated by the complexation with these agents. The topics of this conference (Session 1 - Isolation, fractionation and characterization; Session 2 - Biological and chemical transformation and degradation; Session 3 - Complex formation and interactions with solids; Session 4 - Biological activity; and session 5 Halogenation of humic substances) were selected to represent areas of current environmental interest...

Beschreibung / Inhaltsverzeichnis: PREFACE Through the last few decades inversion concepts have become an integral past of experimental data interpretation in several branches of science. In numerous cases similar inversion-like techniques were developed independently in separate disciplines, sometimes based on different lines of reasoning, and sometimes not to the same level of sophistication. This fact was realized early in inversion history. In the seventies and eighties "generalized inversion" and "total inversion" became buzz words in Earth Science, and some even saw inversion as the panacea that would eventually raise all experimental science into a common optimal frame. It is true that a broad awareness of the generality of inversion methods is established by now. On the other hand, the volume of experimental data varies greatly among disciplines, as does the degree of nonlinearity and numerical load of forward calculations, the amount and accuracy of a priori information, and the criticality of correct error propagation analysis. Thus, some clear differences in terminology, philosophy and numerical implementation remain, some of them for good reasons, but some of them simply due to tradition and lack of interdisciplinary communication. In a sense the development of inversion methods could be viewed as an evolution process where it is important that "species" can arise and adapt through isolation, but where it is equally important that they compete and mate afterwards through interdisciplinary exchange of ideas. This book was actually initiated as a proceedings volume of the "Interdisciplinary Inversion Conference 1995", held at the University of Aarhus, Denmark. The aim of this conference was to further the competition and mating part of above-mentioned evolution process, and we decided to extend the effect through this publication of 35 selected contributions. The point of departure is a story about geophysics and astronomy, in which the classical methods of Backus and Gilbert from around 1970 have been picked up by helioseismology. Professor Douglas Gough, who is a pioneer in this field, is the right person to tell this success story of interdisciplinary exchange of research experience and techniques [1-31] (numbers refer to pages in this book). Practitioners of helioseismology like to stress the fact that the seismological coverage on the Sun in a sense is much more complete and accurate than it is on Earth. Indeed we witness vigorous developments in the Backus & Gilbert methods (termed MOLA/SOLA in the helioseismology literature) [32-59] driven by this fortunate data situation. Time may have come for geophysicists to look into helioseismology for new ideas. Seismic methods play a key role in the study of the Earth's lithosphere. The contributions in [79 - 130,139 - 150] relate to reflection seismic oil exploration, while methods for exploration of the whole crust and the underlying mantle axe presented in [131 - 138, 151 - 166]. Two contributions [167 - 185] present the application of inversion for the understanding of the origin of petroleum and the prediction of its migration in sedimentary basins. Inversion is applied to hydrogeophysical and environmental problems [186 - 222], where again developments are driven by the advent of new, mainly electromagnetic, experimental techniques. The role of inversion in electromagnetic investigations of the lithosphere/astenosphere system as well as the ionosphere axe exemplified in [223 - 238]. Geodesy has a fine tradition of sophisticated linear inversion of large, accurate sets of potential field data. This leads naturally to the fundamental study of continuous versus discrete inverse formulations found in [262-275]. Applications of inversion to geodetic satellite data are found in [239 - 261]. General mathematical and computational aspects are mainly found in [262 - 336]. Nonlinearity in weakly nonlinear problems may be coped with by careful modification of lineaxized methods [295 - 302]. Strongly nonlinear problems call for Monte Carlo methods, where the cooling scedule in simulated annealing [303 - 311,139 - 150] is critical for convergence to a useful (local) minimum, and the set of consistent models is explored through importance sampling [89 - 90]. The use of prior information, directly or indirectly, is a key issue in most contributions, ranging from Bayesian formulations based a priori covariances e.g. [98 - 112,122 - 130, 254 - 261], over more general but also less tractable prior probability densities [79 - 97], to inclusion of specific prior knowledge of shape [284 - 294, 312 - 319]. Given the differences and similarities in approach, can we benefit from exchange of ideas and experience? In practice ideas and experience seldom jump across discipline boundaries by themselves. Normally one must go and get them the hard way, for instance by reading and understanding papers from disciplines far from the home ground. Look at the journey into the interdisciplinary cross-field of inversion techniques as a demanding safari into an enormous hunting ground. This book is meant to provide a convenient starting point.

Beschreibung / Inhaltsverzeichnis: PREFACE Turbidity currents have been comprehensively studied in the past although much remains unknown about both their flow characteristics and resultant sedimentary deposits. Much of this uncertainty arises from the catastrophic nature of their formation which makes them difficult to study in the environment, and has resulted in the majority of studies being experimental or theoretical. Experiments have shown that reversals in the flow of density currents can be associated with the generation of internal solitary waves. This is in contrast to the belief held by many workers that the reversal of a turbidity current simply generates an identical flow travelling in the opposite direction. This book arose from the need for a detailed experimental study to examine the effects and to consider the consequences of density current reversals from a variety of obstructions to their flow. The first part of this book comprises a detailed review of literature covering the fluid dynamics and sedimentology relevant to the experimental study (chapter one). Chapter two presents the results from the comprehensive experimental programme which are discussed and compared with appropiate theoretical hypotheses. This permits the synthesis of a model for the general features of flows that result from the incidence of density currents upon obstructions to the flow. The application of this model to both modern and ancient turbidite systems is then discussed in chapter three. This book is suitable for earth scientists with an interest in the dynamics of turbidity currents. In addition, workers from other fields such as applied maths, meteorology and engineering who have an interest in density currents and bores in practical situations may find it useful...

Beschreibung / Inhaltsverzeichnis: PREFACE The application of thermal analysis to earth science has a long history. This is evidenced by the extensive coverages by Mackenzie (1957, 1970), Langier-Kuzniarowa (1967), Schultze (1971), Liptay (t973), Smykatz- Kloss (1974), Todor (1976) and Heide (1982). The chief thermal method has been differential thermal analysis (DTA). Additionally, thermogravimetry (TG; Duval, 1963; Keattch, 1969; Earnest, 1988) and thermodilatometry (Schomburg & Strörr, 1984) have gained some importance. All these methods are still widely ltsed. But recently several new techniques have gained attention, such as thermomagnetometry, thermomechanical analysis and thermosonimetry. Improved equipment made possible the application of thermal methods to problems in thermodynamics and kinetics (e.g. by means of differential scanning calorimetry, DSC). This progress in the construction of new instruments as well as the combination of existing methods to enable simultaneous determinations (e.g. TG/DTA; TG/IR spectroscopy; DTA/mass spectrometry; DTA/microscopy; high-pressure DTA) have led to a resurgence in the use and application of thermal analysis in the earth sciences. Here the applications cover such diverse areas as the examination of individual minerals, mineral mixtures, rocks, soils, ceramics, cements, raw materials as well as their industrial evaluation, performance assessment and quality control. In the field of solid fossil fuels thermal determinations range from proximate analysis of inorganic constituents and the measurement of calorific values to the assessment of the environmental aspects of fly ashes and mineral residues. To support this tendency, the International Confederation for Thermal Analysis (ICTA) has recently founded a "Committee for Thermal Analysis in Geosciences". The aim of this committee shall be to discuss, improve and distribute the knowledge about the possibilities of solving geoscientific questions by means of thermal analytic methods...

Beschreibung / Inhaltsverzeichnis: Papers from an international meeting held at the University of Alaska, Fairbanks in August, 1990

Beschreibung / Inhaltsverzeichnis: ing within the downgoing plate, and appears to be assoeiated with segmentation of the subdueting plate produeed by forees related to the subduetion of the Louisville Ridge. To analyze fault plane heterogeneities in the northern Solomon Islands subdue­ tion segment and their association with rupture eharaeteristics in general and the existenee of earthquake doublets in partieular, Xv and SCHWARTZ study in detail two sets of doublets, from 1974 and 1975, and then reloeate 85 underthrusting events in the area. The authors find that few smaller magnitude events overlap asperity regions, and that the majority of small magnitude underthrusting earth­ quak es oeeupy a segment that has never experieneed a magnitude greater than 7.0 earthquake in the historie times. It will be of great value to soeiety when seismologists and geophysieists are able to monitor and prediet the pattern of geophysieal phenomena assoeiated with subduetion; this issue presents a modest step towards this goal. PAGEOPH, Vol. 140, No. 2 (1993) 0033 ~4553;93;020 183 ~ 28$1.50 + 0.20;0 © 1993 Birkhäuser Verlag, Basel Slip Partitioning along Major Convergent Plate Boundaries 2 GUANG YU,l STEVEN G. WESNOUSKY,l and GÖRAN EKSTRÖM Abstract-Along plate boundaries characterized by oblique convergence, earthquake slip vectors are commonly rotated toward the normal of the trench with respect to predicted plate motion vectors. Consequently, relative plate motion along such convergent margins must be partitioned between displacements along the thrust plate interface and deformation within the foreare and back-are regions.

Beschreibung / Inhaltsverzeichnis: Jean-Christophe Sempéré, Brian P. West, and Louis Géli: The Southeast Indian Ridge between 127° and 132°40′E: contrasts in segmentation characteristics and implications for crustal accretion / Geological Society, London, Special Publications, 118:1-15, doi:10.1144/GSL.SP.1996.118.01.01 --- Philippe Blondel: Segmentation of the Mid-Atlantic Ridge south of the Azores, based on acoustic classification of TOBI data / Geological Society, London, Special Publications, 118:17-28, doi:10.1144/GSL.SP.1996.118.01.02 --- Eddie McAllister and Johnson R. Cann: Initiation and evolution of boundary-wall faults along the Mid-Atlantic Ridge, 25–29°N / Geological Society, London, Special Publications, 118:29-48, doi:10.1144/GSL.SP.1996.118.01.03 --- Simon Allerton, Roger C. Searle, and Bramley J. Murton: Bathymetric segmentation and faulting on the Mid-Atlantic Ridge, 24°00′N to 24°40′N / Geological Society, London, Special Publications, 118:49-60, doi:10.1144/GSL.SP.1996.118.01.04 --- Kate Lawson, Roger C. Searle, Julian A. Pearce, Paul Browning, and Pamela Kempton: Detailed volcanic geology of the MARNOK area, Mid-Atlantic Ridge north of Kane transform / Geological Society, London, Special Publications, 118:61-102, doi:10.1144/GSL.SP.1996.118.01.05 --- Rodey Batiza: Magmatic segmentation of mid-ocean ridges: a review / Geological Society, London, Special Publications, 118:103-130, doi:10.1144/GSL.SP.1996.118.01.06 --- C. J. Robinson, R. S. White, M. J. Bickle, and T. A. Minshull: Restricted melting under the very slow-spreading Southwest Indian ridge / Geological Society, London, Special Publications, 118:131-141, doi:10.1144/GSL.SP.1996.118.01.07 --- Stephen J. Edwards, Trevor J. Falloon, John Malpas, and Rolf B. Pedersen: A review of the petrology of harzburgites at Hess Deep and Garrett Deep: implications for mantle processes beneath segments of the East Pacific Rise / Geological Society, London, Special Publications, 118:143-156, doi:10.1144/GSL.SP.1996.118.01.08 --- Rachel M. Haymon: The response of ridge-crest hydrothermal systems to segmented, episodic magma supply / Geological Society, London, Special Publications, 118:157-168, doi:10.1144/GSL.SP.1996.118.01.09 --- C. R. German, L. M. Parson, B. J. Murton, and H. D. Needham: Hydrothermal activity and ridge segmentation on the Mid-Atlantic Ridge: a tale of two hot-spots? / Geological Society, London, Special Publications, 118:169-184, doi:10.1144/GSL.SP.1996.118.01.10 --- C. J. MacLeod and C. E. Manning: Influence of axial segmentation on hydrothermal circulation at fast-spreading ridges: insights from Hess Deep / Geological Society, London, Special Publications, 118:185-198, doi:10.1144/GSL.SP.1996.118.01.11 --- V. V. Zaykov, V. V. Maslennikov, E. V. Zaykova, and R. J. Herrington: Hydrothermal activity and segmentation in the Magnitogorsk-West Mugodjarian zone on the margins of the Urals palaeo-ocean / Geological Society, London, Special Publications, 118:199-210, doi:10.1144/GSL.SP.1996.118.01.12 --- Eve C. Southward, Verena Tunnicliffe, Michael B. Black, David R. Dixon, and Linda R.J. Dixon: Ocean-ridge segmentation and vent tubeworms (Vestimentifera) in the NE Pacific / Geological Society, London, Special Publications, 118:211-224, doi:10.1144/GSL.SP.1996.118.01.13 --- Verena Tunnicliffe, C. Mary R. Fowler, and Andrew G. Mcarthur: Plate tectonic history and hot vent biogeography / Geological Society, London, Special Publications, 118:225-238, doi:10.1144/GSL.SP.1996.118.01.14 --- E. G. Nisbet and C. M. R. Fowler: The hydrothermal imprint on life: did heat-shock proteins, metalloproteins and photosynthesis begin around hydrothermal vents? / Geological Society, London, Special Publications, 118:239-251, doi:10.1144/GSL.SP.1996.118.01.15