Hydraulic parameter identification is a crucial step in hydrogeological investigations. The book proposes a unique and generalized interpretation method for single and multiple pumping tests made in groundwater reservoirs with layered heterogeneity and with or without lateral anisotropy. This method eliminates the drawbacks of the numerous and frequently applied interpretation methods. The book also presents an introduction to inverse modeling, resulting in optimal parameter values with their joint confidence region and the corresponding residuals. Cross sections through this multidimensional region elucidate the relation between the shape of this region and some statistical parameters describing the reliability of the identified parameters. This method is demonstrated by means of five pumping or recharge tests.

In the Fall of 1988, 64 geologists and geophysicists from 11 countries met in Killarney, Ontario, on the north shore of Lake Huron to examine evidence that suggests that the continental crust is exposed in cross-section at several key locations on the Earth's surface. The meeting, which was held under NATO auspices as an Advanced Study Institute, was a landmark event in that it was the first time that many of the lead scientists working on these complexes in relative isolation around the world had' ever gathered together to compare results. The present volume is a compendium of the invited lectures given on the principle sections, plus an array of supporting papers on these and other sections as well as on related topics such as crustal emplacement mechanisms, deformation and rheology. Nearly all of the best known sections are represented, including the Ivrea Zone, Calabria, the Kapuskasing Zone, Fiordland and many others. It is our hope that this Volume will serve as a reference for Earth scientists who are trying to understand levels of the crust not normally exposed to view, as well as a point of departure for new research and a teaching aid to new entrants in this relatively new field of study.

This book represents the proceedings of the 9th written by a very active group of physicists at Kongsberg seminar, held at the Norwegian Mining the University of Oslo - physicists interested in Museum located in the city of Kongsberg about complex systems in general and geo-like systems 70 km Southwest of Oslo. The Kongsberg district in particular. is known for numerous Permian vein deposits of The content of the book is organized into three native silver, and mining activity in the area lasted major parts following the introductory chapter. for more than 300 years, finally ceasing in 1957. Chapters 2 to 7 primarily treat the role of fluids The previous eight Kongsberg seminars were in specific geological environments, ranging from focused on ore-forming processes and all of these sedimentary basins (Chapters 2-3) to contact were organized by Professor Arne Bj0rlykke, now metamorphic/hydrothermal scenarios (Chapters director of the Norwegian Geological Survey. 4-5) and regional metamorphic settings (Chapters Since process-orientated research tends to break 6-7). The following four chapters (8-11) focus down the traditional barriers between the different on various properties of fluid-rock systems that geological disciplines, this seminar has always are critical in controlling flow and transport been a meeting point for people with a variety through rocks. These include: mineral solubility of geological backgrounds.

Proceedings of the NATO Advanced Research Workshop, Bremen, Germany, October 10-14, 1988

Granulites are, by definition, rocks that crystallized at high temperatures. It is generally agreed that they were formed in regions where the geothermal gradient exceeded normal continental values. These rocks commonly display coronitic mineral fabrics which may be used to trace the thermal and geodynamic history of the continental crust. In the same way that eclogites provide information on the earliest stages of some orogenic episodes, granulites usually tell us about later events, including thermal anomalies, thermal reequilibration, CO streaming, crustal melting, and 2 differentiation of the continental crust. Their study is particularly important if we are to under stand the nature of the middle and lower continental crust. Consistent with the contributions I received, the contents of this volume fall into four general areas: Crustal Evolution, Regional Syntheses, F1uids and Petrological Equilibria, Geochemistry and Geophysics. These represent an up-to-date reflection of the centres of interest in the field of granulites. The first manuscripts arrived in September 1988 while the conference was held, the last contribution arrived in November 1989, more than a year later. I apologize to those who were prompt and took deadlines seriously, but I believe that it was worth waiting to secure a product covering most of the important aspects concerning granulite genesis. All papers were vetted by at least two reviewers. I would like to thank RJ. Arculus, N.T. Arndt, P. Barbey, SR. Bohlen, AM. Boullier, M. Brown, T. Chacko, 1.D. Clemens, K.C. Condie, J.C. Duchesne, C. Dupuy, w.G."

Viewed from space, the Earth appears as a globe without a beginning or an end. Encompassing the globe is the atmosphere with its three phases- gaseous, liquid, and solid--moving in directions influenced by sunlight, gravity, and rotation. The chemical compositions of these phases are determined by biogeochemical cycles. Over the past hundred years, the processes governing the rates and reactions in the atmospheric biogeochemical cycles have typically been studied in regions where scientists lived. Hence, as time has gone by, the advances in our knowledge of atmospheric chemical cycles in remote areas have lagged substantially behind those for more populated areas. Not only are the data less abundant, they are also scattered. Therefore, we felt a workshop would be an excellent mechanism to assess the state of-knowledge of the atmospheric cycles of sulfur and nitrogen in remote areas and to make recommendations for future research. Thus, a NATO Advanced Research Workshop ' he Biogeochemical Cycling of Sulfur and Nitrogen in the Remote Atmosphere" was held at the Bermuda Biological Station, St. Georges, Bermuda, from 8-12 October 1984. The workshop was attended by 24 international scientists known for their work in atmospheric cycling in remote areas. This volume contains the back ground papers and the discussions resulting from that workshop. The workshop was organized along the lines of the atmospheric cycle. There were working groups on emission, transport, transformation, and deposi tion."

Agriculture in the industrial world has gone A common interest of the contributors is increas through dramatic changes over the past decades. ing the understanding of the turnover of carbon Mechanization in combination with high inputs of and inorganic nutrients in terestrial ecosystems. fertilizers and pesticides has turned deficits of agri The authors approach this topic from different cultural products into surplus. Over the same directions depending on their interests and ex period we have experienced increased environment pertise. Difficulties are identified in the quantifica al problems in both the atmosphere and our water tion of below-ground production where death and resources, which have been associated with the re-growth, if incorporated into the calculations, changes in management practices. can change production figures considerably as Concern about the potential pollution by compared to values derived from "peak" estimates. nitrogen fertilizers as well as the low utilization The role of root-derived carbon is investigated in efficiency of applied nitrogen by plants has created relation to nutrient competition between roots and a need for a better understanding of nitrogen microorganisms, the cost of N2 fixation and the cycling in the plant-soil-water system. To achieve decomposition of organic nitrogen. Mycorrhizae this, it is neccessary to study process interactions use root-derived carbon and their roles in phos and process regulation in an ecosystem context. phorus conservation and in supplying nutrients to During the last decade many ecosystem studies the host are exemplified.

This book provides a detailed description of light absorption and absorbents in seawaters with respect to provenance, region of the sea, depth of the occurrence and trophicity. The text is based on a substantial body of contemporary research results taken from the subject literature (over 400 references) and the work of the authors over a period of 30 years.

Three symposia on environmental geochemistry in tropical countries, held in Niter6i, Brazil (1993), in Cartagena, Colombia (1996) and in Nova Friburgo, Brazil (1999), made it very clear that tropical geochemistry is of world standard and fast increasing in multi disciplinarily and impact on important geochemical paradigms. It has additionally strong links with the economy of tropical countries, such as mining and industrialisa tion and is in full development for treating environmental problems caused by human activities of urban or industrial origin. We must compliment Prof. Jorge Abriio and his colleagues in Brazil and Dr. Gloria Prieto and her colleagues in Colombia for these ini tiatives. The participation of respectively 180 and 150 scientists, coming from 15 different countries for the first and second symposia, has shown that a large interest exists for tropical environmental geochemistry. It also demonstrates the necessity to understand tropical environmental problems. The organisation of a large international symposium is not possible without the assistance of state and federal authorities, for which those of Brazil and Colombia have to be complimented. The 3rd Symposium on Environmental Geochemistry in Tropical Countries was the last of the series and was attended by 22 countries and 170 participants and treated a number of related environmental and economic problems."

The large and rapidly expanding body ofliterature related to nitrogen cycling in both managed and native terrestrial ecosystems reflects the importance accorded to the behaviour of this vital and often limiting nutrient. Research at the organism, ecosystem and landscape levels commonly addresses questions concerning nitrogen acquisition, internal cycling and retention. Goals for this research include increased agricultural productivity and a better understanding of human impact on local, regional and global nitrogen cycles. Nitrogen cycle research in tropical regions has a long and distinguished history. Research on different aspects of nitrogen cycling in ecosystems of the tropics has been carried out in many regions. In relatively few instances has there, however, been a focus on the biogeochemical cycles at the ecosystem level. The meeting resulting in this volume was an attempt to bring together existing information on nitrogen cycling in ecosystems of Latin America and the Caribbean and discuss this in an ecosystem context.

Many geologists have an equivocal attitude to fluid movements within the crust and the associated changes in the chemical and physical properties of crustal rocks. The controversies earlier this centuary between the "soaks" and the "pontiffs" memorably summarised by H. H. Read (1957) in The Granite Controversy have largely been resolved. Few would now advocate the formation of large granitic bodies by in situ transformation of pre-existing crust as the result of the passage of ichors without the formation of a granitic melt. To many geochemists fluid transport and metasomatism have become slightly suspect processes which at the most locally disturb the primary geochemical and isotopic signatures. While there is common agreement that there are marked differences in the composition of the lower and upper crust, the role of fluid movement as one of the controls of this differentiation is often neglected in favour of suggested primary differences in the composition of igneous rocks emplaced at different depths. Selective fluid transport however provides many geologists with their livelyhood. Without the secondary concentration of commercially important elements by fluids within the crust the mining industry, geological science and human activities based on their products would be very different.

Human activity has dramatically altered the global nitrogen cycle in recent decades. These changes are not evenly distributed around the world; rather, they are greatest in regions of significant industrial and agricultural activity, as the synthesis and use of inorganic fertilizers, cultivation of legumes, burning of fossil fuels, and the simple act of concentrating humans and animals in dense populations all lead to the release of excess, reactive forms of nitrogen into the environment. In part because reactive nitrogen is frequently a limiting nutrient in many terrestrial and aquatic systems, an excess can lead to a variety of adverse effects on both environmental and human health. The North Atlantic Ocean and its contributing watersheds constitute a region which has seen perhaps the greatest increase in anthropogenically-derived nitrogen. In May of 1994, the International Scope Nitrogen Project, with funding from the Andrew Mellon Foundation, the United Nations Environment Program, and the World Meteorological Organization, sponsored a workshop held on Block Island, RI, USA, entitled Nitrogen Dynamics of the North Atlantic Basin'. More than 50 scientists from 12 different countries convened with a unique set of goals: an integrated and comprehensive estimate of the current nitrogen cycle of the ocean, coastal systems, and contributing watersheds of the North Atlantic region; an analysis of human-induced changes to those cycles; and an assessment of the current and future effects of human-induced changes to nitrogen cycling throughout the globe.

During the last few years, carbonatites have received a considerable amount of attention. Some of this interest was no doubt kindled by the importance of volatiles in the Earth's mantle, particularly CO , by the fact that carbonatites 2 can be used to monitor the chemical evolution of the sub-continental upper mantle, and by the fact that carbonatites may be effective metasomatizing agents at both mantle and crustal levels. The interest in Oldoinyo Lengai has extended over at least 100 years, but it was not until the eruptions of 1960, when the unique carbonatitic nature of its lavas was recognized, that the volcano took on special significance in volcanology and igneous petrology. The recognition of carbonatitic flows coin cided with the first successful laboratory experiments carried out on carbonatitic melts. Since then, Oldoinyo Lengai has formed a cornerstone in all carbonatite discussions. It is probably true to say that the findings from Oldoinyo Lengai have dominated our ideas about carbonatites, in spite of the fact that the alkali rich, natrocarbonatitic lavas of Oldoinyo Lengai are markedly different from other carbonatites.

This book focuses on sediments as a pollutant in natural freshwater and marine habitats, and as a vector for the transfer of chemicals such as nutrients and contaminants. Sediment-water research is carried out all over the world within a variety of disciplines. The selected papers cover three main topics relating to assessment and/or restoration of disturbed watersheds, sediment-water linkages in terrestrial and aquatic environments and evaluation of sediment and ecological changes in marine and freshwater habitats. Innovative research in both developed and less developed countries is included. Both fundamental research, insight into applied research and system management are covered. The volume will also appeal to readers involved in sediment geochemistry and dynamics, aquatic habitats, water quality, aquatic ecology, river morphology, restoration techniques and catchment management.

Marble in Ancient Greece and Rome: Geology, Quarries, Commerce, Artifacts Marble remains the sine qua non raw material of the an cient Greeks and Romans. Beginning in the Bronze Age sculptu re began in marble and throughout classical times the most im portant statues, reliefs, monuments and inscriptions were made of it. Yet, quarry sources changed in time as preferences for different marbles were influenced by local traditions, the pos sibilities of transport, esthetic tastes, and economics. Marble studies and the identification of the provenance of marble can thus reveal much about Greek and Roman history, trade, esthe tics and technology. Persons in many disciplines are studying various aspects of Greek and Roman marble usage. Geologists and geochemists are working on methods to determine the provenance of marble; ar chaeologists are noting changing patterns of import and use in excavation and discovering how improving quarrying techniques and prelimihary dressing of the extracted material influenced the final shape of artifacts; ancient historians are now under standing quarry organization and bureaucracies that controlled marble production and trade; art historians are seeing how phy sical characteristics of the stone affected the techniques and style of sculpture; architects and engineers are interested in quarry technologies and usage in building construction. These specialists drawn from many disciplines rarely have an opportu nity to compare notes and see how each can contribute to the research effort of others."

PGE V-Voisey's Bay (Canada) D -Duluth Complex (USA) K-Kambalda (Australia) M-Merensky Reef (Bushveld) N -Noril'sk region (Russia) P-Pechenga(Russia) S-Sudbury (Canada) T-Thompson (Canada) J -Jinchuan (China) L-Lac des lies (Canada) PR-Platreef (Bushveld) Po-Portimo Complex (Finland) R-Raglan (Canada) U-UG-2 chromitite (Bushveld) Z-Great Dyke of Zimbabwe e-Mt Keith (Australia) . a. -Perseverance (Australia) +-Stillwater (USA) 0 0 0 'c9 -~ Ni+Co Cu Relative value of Ni+Co Fig. 1. 1. Relative va1ue of the contributions of Ni+Co, Cu and PGE to the mag- matic su1fide deposits listed in Table 1. 1 sulfide deposits are closely related to bodies of mafic or ultramafic rock, and the most convenient way in which to consider them is in terms of the type of magma responsible for the rocks with which they are associated. Typically the type of magma involved bears a close relationship to the tec- tonic setting within which it was emplaced. The locations of important deposits, both Ni-Cu dominant and PGE dominant, are shown in Fig. 1. 2. Considering first Ni-Cu deposits, these are further divided into six classes (Table 1. 2) on the basis of their associated magma type. Class NC- 1 (Chap. 3) comprises those related to komatiitic magmatism. Currently known deposits fall into two sub-classes, those related to Archean komatiites ( e. g. the deposits of Western Australia, Zimbabwe and the Abitibi belt of Canada) and those related to Proterozoic komatiites (e. g. those ofthe Raglau and Thompson belts which arebothin Canada)l.

This book consists of papers presented at a symposium "PLANT-INDUCED SOIL CHANGES: PROCESSES AND FEEDBACKS" that was held during the American Society of Agronomy-Soil Science Society of America Annual Meeting in Indianapolis, November 4-8, 1996. The papers were also pub of Biogeochemistry (Vol. 42, nos. 1 and 2, 1998). The lished in a special issue symposium was built on the growing realisation that plant-induced changes in soil feed back in various ways to natural vegetations, giving rise to a plethora of plant-soil interactions beyond the classical one-way cause-and-effect pathways plant-to-soil and soil-to-plant. The aim of this special issue is not in the first place to present new research findings, but to review and discuss the more holistic aspects of plant-soil interactions, providing more room for speculation than do most collections of research papers. After a general introduction which emphasises ecological and evolutionary aspects of plant-soil interac ions (van Breemen and Finzi), three papers deal with particular effects of plants on soil properties: mineralogy (Kelly et al. ), soil structure (Angers and Caron) and soil fertility (Berendse). Next, five papers take up plant-soil interactions in specific biomes: forests (Binkley and Giardina; Gobran et al. ), grasslands (Burke et al.; Epstein et al. ) and deserts (Schlesinger and Pilmanis). Two papers discuss plant-soil interactions via effects of differences in litter quality in specific ecosystems: California's pygmy forest (Northup et al. ) and the Alaskan Taiga (Schimel et al. )."

2Gpa has increased to more than 15. This indicates that subduction of continental fragments to depths of 100-150 km may have played a significant role in the formation of mountain belts. This volume brings together the geochemical, geophysical and geodynamical approaches to study the processes active during ultrahigh-pressure (UHP) tectonics. The collection of papers demarkates the frontier of our understanding of the creation, preservation, and exhumation of ultrahigh-pressure rocks. Audience: This volume will be of interest to any earth scientist interested in ultrahigh pressure processes and the formation and modification of continental crust.

The extraordinary growth of the computer and semiconductor industries and the increasing consumption of indium in these technologies in recent years have placed major constraints on current and future reserves of this metal. In the past, geoscientists have noticed the occurrence of indium in a large variety of ore de posits and detailed geochemical and mineralogical work is available for a few ex amples. However, despite the current technological interest, there is no compre hensive textbook that deals with all aspects of indium mineralization and economics. The present study attempts to develop a general metallogenic concept for indium in identifying the essential enrichment processes and their economic significance. The study 'Indium Geology, Mineralogy, and Economics' was commissioned and funded by the German Federal Institute for Geosciences and Natural Re sources (BGR Hannover) and is a contribution to the research program 'BGR 2000 - Raw Materials with Short Lifetime Reserves'. This program focuses on raw materials with known reserves confined to the next 20-25 years at static de mand. The future availability of reserves is usually estimated by dividing the known reserves by the current annual consumption. In fact, lifetimes of reserves are inappropriate measures because they depend on many parameters and there fore represent a "snapshot" of a dynamic system. In order to provide a sustainable use of raw materials with short lifetime reserves, a significantly higher amount of innovation is needed compared to raw materials with long lifetime reserves."

Over the past decade the scientific activities of the Joint Global Ocean Flux Study (JGOFS), which focuses on the role of the oceans in controlling climate change via the transport and storage of greenhouse gases and organic matter, have led to an increased interest in the study of the biogeochemistry of organic matter. There is also a growing interest in global climate fluctuations. This, and the need for a precise assessment of the dynamics of carbon and other bio-elements, has led to a demand for an improved understanding of biogeochemical processes and the chemical characteristics of both particulate and dissolved organic matter in the ocean. A large amount of proxy data has been published describing the changes of the oceanic environment, but qualitative and quantitative estimates of the vertical flux of (proxy) organic compounds have not been well documented. There is thus an urgent need to pursue this line of study and, to this end, this book starts with several papers dealing with the primary production of organic matter in the upper ocean. Thereafter, the book goes on to follow the flux and characterization of particulate organic matter, discussed in relation to the primary production in the euphotic zone and resuspension in the deep waters, including the vertical flux of proxy organic compounds. It goes on to explain the decomposition and transformation of organic matter in the ocean environment due to photochemical and biological agents, and the reactivity of bulk and specific organic compounds, including the air-sea interaction of biogenic gases. The 22 papers in the book reflect the interests of JGOFS and will thus serve as a valuable reference source for future biogeochemical investigations of both bio-elements and organic matter in seawater, clarifying the role of the ocean in global climate change.

This book involves application of the Calphad method for derivation of a self consistent thermodynamic database for the geologically important system Mg0- Fe0-Fe203-Alz03-Si02 at pressures and temperatures of Earth's upper mantle and the transition zone of that mantle for Earth. The created thermodynamic database reproduces phase relations at 1 bar and at pressures up to 30 GPa. The minerals are modelled by compound energy formalism, which gives realistic descriptions of their Gibbs energy and takes into account crystal structure data. It incorporates a detailed review of diverse types of experimental data which are used to derive the thermodynamic database: phase equilibria, calorimetric stud ies, and thermoelastic property measurements. The book also contains tables of thermodynamic properties at 1 bar (enthalpy and Gibbs energy of formation from the elements, entropy, and heat capacity, and equation of state data at pressures from 1 bar to 30 GPa. Mixing parameters of solid solutions are also provided by the book. Table of Contents Introduction to the Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VII Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IX Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XI Co-Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XIII Vitae of Co-Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XV CODATA Task Group on Geothermodynamic Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XXIII Chapter 1. Thermodynamics and Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. 2 Thermodynamic Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. 3 Experimental Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. 4 Programs and Assessment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 System and Phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 5 Chapter 2. Experimental Phase Equilibrium Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 The Si02 System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2. 1 2. 2 The Fe-0 System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2. 3 The Fe-Si-0 System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. 4 The Mg0-Si0 System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

This volume follows a Specialized Symposium on "Mantle denudation in slow spreading ridges and in ophiolites," held at the XII EUG Meeting in Strasbourg, spring 1993. During the meeting it was felt that the contribu tions to the Symposium justified a volume presenting its main scientific achievements. The present title of the volume shows that the center of inter est has slightly shifted with respect to the initial objective: in order to under stand the processes involved in accretion taking place at oceanic ridges, it is crucial to study the interaction between uppermost mantle and lower crust. The approach favored here is that of petrological and structural analysis of oceanic rocks in present-day oceanic ridges combined with similar studies in ophiolites. Rock specimen collected by submersibles or dredge hauls in oceanic ridge environments provide a "ground truth." However, except for areas such as the MARK (Mid-Atlantic Ridge ne ar Kane fracture zone) where, thanks to multiple submersible dives, the local geology is known with aprecision even better than in many onshore ophiolites, mutual rela tionships between uppermost mantle and lower crust are poorly known. In contrast, onshore ophiolites provide a necessary large-scale picture built up over many years of structural and petrological mapping."

The Bear Brook Watershed in Maine (BBWM) is a long-term, whole-watershed study examining the effects of experimentally elevated N and S deposition on a treated watershed, in comparison to the adjacent reference watershed. The study is in a northern New England, USA, forested ecosystem, and focuses on soil and stream hydrological and biogeochemical processes, and chemical responses of vegetation. Relative to the reference watershed, the treated ecosystem has migrated biogeochemically towards N saturation, and soil and stream acidification. Some of the responses to N amendments were not expected nor predicted by available models.

The book emphasizes various aspects of processing secondary sources for recovery of uranium. The field of secondary resource processing is gaining ground over the last few years as it is eco-friendly, economical and in tune with the philosophy of sustainable development. The book is the first one of its type in the area and includes a succint and comprehensive description of related areas of ore mineralogy, resource classification, processing principles involved in uranium solubilisation followed by separation and safety aspects. The clear organisation and the carefully selected figures and tables makes the treatment invaluable for practising engineers, research workers and academic institutions.