After the spectacular successes of the 1960's and 1970's, the mineral exploration business is at a crossroads, facing uncertain t: imes in the decades ahead. This situation requires a re-thinking of the philosophy guiding mineral exploration if it is to emulate its recent performance. The ma: i. n argument of a previous volume titled "Designing Opt: lmal Strategies for Mineral Exploration," published in 1985 by Plenum Publishing Corporation of New York, is that a possible answer to the challenge facing mineral explorationists lies in the philosophy of opt: irn1zation. This new approach should help exploration staff make the best achievable use of the sophisticated and costly technology which is presently available for the detection of ore deposits. The main emphasis of the present volume is placed on the mathematical and computational aspects of the opt: irn1zation of mineral exploration. The seven chapters making up the ma: i. n body of the book are devoted to the description and application of various types of computerized geomathematical models which underpin the optimization of the mineral exploration sequence. The topics covered include: (a) the opt: lmal selection of ore deposit types and regions of search, as well as prospecting areas within the regions (Chapters 2, 3, 4, 6), (b) the designing of airborne and ground field programs for the opt: lmal coverage of prospecting areas (Chapters 2, 3, 4), (c) delineation and evaluation of exploration targets within prospecting areas by means of opt: irn1zed models (Chapter 5).

Mine Safety combines detailed information on safety in mining with methods and mathematics that can be used to preserve human life.

By compiling various recent research results and data into one volume, Mine Safety eliminates the need to consult many diverse sources in order to obtain vital information. Chapters cover a broad range of topics, including: human factors and error in mine safety, mining equipment safety, safety in offshore industry and programmable electronic mining system safety.

They are written in such a manner that the reader requires no previous knowledge to understand their contents. Examples and solutions are given at appropriate places, and there are numerous problems to test the reader's comprehension.

Mine Safety will prove useful for many individuals, including engineering and safety professionals working in the mining industry, researchers, instructors, and undergraduate and graduate students in the field of mining engineering.

Phase transitions in minerals are of interest to a wide spectrum of scientists - geolo- gists, mineralogists, solid state chemists, and physicists. We have now reached the point where mean field theory or Landau Theory of phase transitions as a function of temperature, pressure, or chemical composition can be usefully applied to natural materials, resulting in an improved understanding of the thermodynamics of signifi- cant constituents of the earth. Given the chemical complexity of so many silicate solid solutions, there are two distinct approaches to the problems posed by common minerals: one is to con- centrate on model compounds which could be synthetic analogs or natural end- members; the other is to work on typical minerals, with all the disorder and inhomogeneity that this implies. Model compounds provide the elements needed to build up a realistic understanding of the thermodynamic behavior of natural inor- ganic materials in all their complexity. In the first part of the book, a number of papers are devoted to structural phase transitions in quartz, Na-and Ca-feldspars, MgSi0 perovskite, and PbI , where Landau Theory and lattice and molecular 3 2 dynamics have been used to explain or predict thermodynamic behavior. A different thermodynamic approach has been used to understand phase separation and atomic ordering in solid solutions such as olivines, pyroxenes, rhombohedral carbonates and oxides. E. Salje (Chapter 1) applies the Landau Theory for the second-order phase transi- tion to the feldspar end-members albite, NaAlSi0 , and anorthite, CaAlSi0 .

work on structural and stratigraphic relationships is presented from various parts of the mountain belt. In the first paper of the section, R. O. Greiling (Heidelberg) describes the Middle Allochthon of Vasterbotten, northern Sweden, where tectonic windows through the Upper Allochthon (Seve Nappe) show that the Middle Allochthon has a similar lithostratigraphy to that of the Stalon Nappe Complex of the eastern Caledonian margin but with a more ductile deformation and metamorphosed to a higher grade following thrust emplacement. These relations are explained by suggesting that the window rocks were initially subducted beneath a colliding western plate but were later accreted to the base of the western plate and thrust with it. The thrust geometry of the windows, described as antiformal stacks, agrees with this model. The Middle Allochthon of the Caledonian margin in northern Sweden is described by R. O. Greiling and R. Kumpulainen (Heidelberg and Stockholm) who record two distinct metasedimentary units separated by a thick zone of mylonites interpreted as a lateral thrust ramp. Turbidites in the northern unit were derived from an unidentified igneous source to the east and cannot be correlated with other sequences in the Middle Allochthon. In another paper dealing with the northern Swedish Caledonides, L. Hansen (Uppsala) describes down-to-the-west normal faults cutting the autochthonous Cambrian sediments in the tunnel sections of the Vietas Hydropower Station, but themselves being truncated by the basal decollement of the Lower Allochthon.

All existing introductory reviews of mineralogy are written accord ing to the same algorithm, sometimes called the "Dana System of Mineralogy." Even modern advanced handbooks, which are cer tainly necessary, include basic data on minerals and are essentially descriptive. When basic information on the chemistry, structure, optical and physical properties, distinguished features and para genesis of 200-400 minerals is presented, then there is practically no further space available to include new ideas and concepts based on recent mineral studies. A possible solution to this dilemma would be to present a book beginning where introductory textbooks end for those already famil iar with the elementary concepts. Such a volume would be tailored to specialists in all fields of science and industry, interested in the most recent results in mineralogy. This approach may be called Advanced Mineralogy. Here, an attempt has been made to survey the current possibilities and aims in mineral mater investigations, including the main characteristics of all the methods, the most important problems and topics of mineralogy, and related studies. The individual volumes are composed of short, condensed chap ters. Each chapter presents in a complete, albeit condensed, form specific problems, methods, theories, and directions of investigations, and estimates their importance and strategic position in science and industry."

Identificationof rock-forming minerals in thin section is a key skill needed by all earth science students and practising geologists. This translation of the completely revised and updated German second edition (by Leonore Hoke, Institute of Geological and Nuclear Sciences, New Zealand) provides a comprehensive guide to identifying 140 of the most important rock-forming mineral species. The book is divided into three main parts. Part A is a practical guide to the fundamentals of crystal optics, polarization microscopy and the practical use of microscopes. Part B gives a detailed description of the characteristic optical features, special features, and the paragenesis of the most common rock-forming minerals. This well-illustrated part is divided into opaque minerals, isotropic, uniaxial and optical biaxial mineral groups. Part C contains identification tables for the minerals and diagrams showing the international classification of magmatic rocks, as well as a colour plate section showing crystal forms of minerals. The book will provide an invaluable guide to all undergraduate earth scientists, as well as to professional geologists requiring an overview of mineral identification in thin section.

This book has been prepared by the collaborative effort of two somewhat separate technical groups: the researchers at the Institute for Petroleum and Organic Geochemistry, Forschungszentrum Jii lich (KFA), and the technical staff of Integrated Exploration Systems (IES). One of us, Donald R. Baker, from Rice University, Houston, has spent so much time at KFA as a guest scientist and researcher that it is most appropriate for him to contribute to the book. During its more than 20-year history the KFA group has made numerous and significant contributions to the understanding of petroleum evolution. The KFA researchers have emphasized both the field and laboratory approaches to such important problems as source rock recognition and evaluation, oil and gas generation, maturation of organic matter, expulsion and migration of hydrocarbons, and crude oil composition and alteration. IES Jiilich has been a leader in the development and application of numerical simulation (basin modeling) procedures. The cooperation between the two groups has resulted in a very fruitful synergy effect both in the development of modeling software and in its application. The purpose of the present volume developed out of the 1994 publication by the American Association of Petroleum Geologists of a collection of individually authored papers entitled The Petroleum System - From Source to Trap, edited by L. B. Magoon and W. G. Dow."

The most renowned naval officer of the mid-nineteenth century, Thomas Cochrane, Tenth Earl of Dundonald (1775-1860), served in wars against Spain and France, retiring as an admiral in the Royal Navy. He was also an M.P., vociferously calling for naval reform in Parliament. Due to a financial scandal, he left the Royal Navy for a period and became a celebrated mercenary, commanding naval forces in the wars of independence of Chile, Peru, Brazil and Greece. First published in 1851, this work contains notes on a voyage of 1849 around the West Indies and North America. Describing the peoples and geography encountered, it offers progressive remarks on the end of slavery, criticisms of plantation owners, and suggestions for commercial improvements. The book remains of enduring interest to scholars of naval, colonial and Caribbean history.

The collection of papers in this volume is a direct result of the Society of Economic Paleontologists and Mineralogists Research Symposium on "Thermal History of Sedimentary Basins: Methods and Case Histories" held as part of the American Association of Petroleum Geologists Annual Convention in New Orleans in March 1985. The original goal of the sym posium was to provide a forum where specialists from a variety of dis ciplines could present their views of methods that can be used to study the thermal history of a sedimentary basin or an important portion of a basin. An explicit part of that goal was to illustrate each method by presentation of a case history application. The original goal is addressed by the chapters in this volume, each of which emphasizes a somewhat different approach and gives field data in one way or another to illustrate the practical useful ness ofthe method. The significance of our relative ignorance of the thermal conductivities of sedimentary rocks, especially shales, in efforts to understand or model sedimentary basin thermal histories and maturation levels is a major thrust of the chapter by Blackwell and Steele. Creaney focuses on variations in kerogen composition in source rocks of different depositional environments and the degree to which these chem- . ically distinct kerogens respond differently to progressive burial heating."

The chapters making up this volume are based on the presentations given by their authors at the NATO Advanced Research Workshop (ARW) , also entitled "The Microbiology of Atmospheric Trace Gases: Sources, Sinks and Global Change Processes", held between 13-18 May 1995 at II Ciocco, Castelvecchio Pascoli, Tuscany, Italy. Four reports of Working Group discussions on aspects of trace gas microbiology and climate change are also included in the volume, prepared by rapporteurs designated at the ARW. All the papers here presented have been subjected to peer review by at least two referees and corrections and amendments made where necessary before their acceptance for pUblication in this volume. The ARW was set up to address a wide range of issues relating to atmospheric trace gas microbiology and the organizing group was aware of the burgeoning of studies on gas metabolism and on global effects of atmospheric trace gases over the past two decades. This research effort has led to a number of specialist and generalist meetings including the triennial series of symposia on the metabolism of one-carbon compounds, colloquia concerned with dimethyl sulfide and its precursor, DMSP, through to the Intergovernmental Panels on Climate Change, which have addressed the impact of increasing levels of atmospheric carbon dioxide, methane, nitrous oxide and chlorofluorocarbons on global climate. Over recent years methane and nitrous oxide showed rates of increase in the atmosphere of 40-48 and 3-4. 5 Tg/year, respectively.

As a method of structure analysis, electron diffraction has its own spe cial possibilities and advantages in comparison to the X -ray method for the study of finely dispersed minerals with layer or pseudolayer structures. How ever, possibly because of the prior existence of the X-ray method, which found universal application in different fields and attracted the main efforts of spe cialists, electron diffraction has been unevenly disseminated and developed in different countries. In particular, the oblique texture method, which gives very complete and detailed structural information, has been mainly used in the Soviet Union, where electron-diffraction cameras specially suited to the method have been constructed. In other countries, studies have been made of micro-single crystals, because these studies could be carried out with existing electron microscopes. It should be recognized that the scale of distribution and use attained by electron-diffraction methods, at present limited by exist ing experimental conditions. is more than justified by the value of the results which may be obtained by their aid. The author hopes that the present book will give the reader a fuller idea of the valuable advantages of the method, and of the structural crystallography picture which has been built up for clay minerals, and layer silicates in general, from electron-diffraction data. The time between the appearance of this book and that of the Russian edition has been comparatively short."

This volume contains a selection of papers presented to the Fourth International Symposium on Environmental Biogeochemistry (ISEB), and a conference on Biogeochemistry in Relation to Mining Industry and Environmental Pollution (Leaching Conferenc, held in Canberra, Aust ralia on August 26-31 and September 3-4, 1979, respectively. The ISEB were established to provide "a forum for uninhibited exchange of information and ideas among the biological, chemical, atmospheric and geolopical scientists working in the common area of biogeochemistry, encompassing soil and other earth sciences as weIL as the hydrosphere and atmosphere," By linking the fourth ISEB with the Leachinp Conference the scop.e of discussions was extended to encompass the application of biogeochemical processes to the mining industry. This wide-ranging philosophy is reflected in the breadth and diversity of the subjects covered in this book. The published papers are expanded versions of those presented at the meetings. They have all been scrutinized by at least one referee in addition to the editors. About 20% of the contributions to the meetings are not included, either because authors did not wish to publish or because the papers were not accepted by the editors."

Igneous petrology was to some extent essentially a descriptive sci ence until about 1960. The results were mainly obtained from field work, major element analyses, and microscopical studies. During the 1960's two simultaneous developments took place, plate tectonics became generally accepted, and the generation of magmas could now be related to the geodynamic features like convection cells and subduction zones. The other new feature was the development of new analytical apparatus which allowed high accuracy analyses of trace elements and isotopes. In addition it became possible to do ex perimental studies at pressures up to 100 kbar. During the 1970's a large amount of analytical data was obtained and it became evident that the igneous processes that control the compositions of magmas are not that simple to determine. The composition of a magma is controlled by the compositions of its source, the degree of partial melting, and the degree of fractionation. In order to understand the significance of these various processes the relationship between the physical processes and their geochemical consequences should be known. Presently there are several theories that attempt to explain the origin of the various magma types, and these theories can only be evaluated by turning the different ideas into quantitative models. We will so to speak have to do some book keeping for the various theories in order to see which ones are valid. the present book is intended as an introduction to the more fun damental aspects of quantitative igneous petrology."

Basalt is the most voluminous of all the igneous rocks. Extensive field, experimental, petrographic and geochemical studies of basalt have provided us with a considerable understanding of igneous petrogenesis, plate tectonics, and crust-mantle interaction and exchange. One important aspect of geology that has developed over the last few decades is the study of oceanic basalts. The ocean basins cover about two thirds of the earth's surface and are floored by a basement of oceanic basalt that is continuously undergoing generation at spreading centres and destruction at subduction zones, a process which throughout geological time is recognized as the principal means of generating new crust. The study of oceanic basalts enables us to understand better the generation and recycling of crustal materials (including the continental crust), and the exchange between oceanic crust and seawater via hydrothermal activity. Compositional variations displayed by oceanic basalts provide windows into the mantle, and the identification of isotopically-distinct mantle reservoirs demonstrates that the source of oceanic basalts is heterogeneous and is controlled by convection and reservoir interactions within the mantle.

This volume illustrates some of the significant aspects of magmatic activity from Devonian (408 million years ago) to early Permian (270 million years ago) times in SW England. This period covers the progressive development of the Variscan mountain-building episode, from initial basin formation to final deformation and the subsequent development of a fold mountain belt - the Variscan Orogen. Both extrusive (volcanic) and intrusive (plutonic) rocks are found in the orogen, and chart the various stages of its magmatic development. The sites described in this volume are key localities selected for conservation because they are representative of the magmatic history of the orogen from initiation to stabilization. Some of the earliest volcanic activity in the Devonian is represented by submarine basaltic and rhyolitic lavas developed in subsiding basins, caused by the attenuation of the existing continental crust. In some cases, extensive rifting and attendant magmatism produced narrow zones of true oceanic crust, whereas elsewhere basaltic volcanism is related to fractures in the continental crust at the margins of the basins. After the filling of the sedimentary basins, and their deformation caused by crustal shortening (late Carboniferous Period), further activity is manifested by the emplacement of the Cornubian granites and later minor basaltic volcanism in the early Permian. Accounts of the constituent parts of this history have enriched geological literature from the nineteenth century onwards, and have contributed to the advancement and understanding of magmatic and tectonic processes.

The chemical interaction of water and rock is one of the most fascinating an d multifaceted process in geology. The composition of surface water and groundwater is largely controlled by the reaction of water with rocks and minerals. At elevated temperature, hydrothermal features, hydrothermal 0 re deposits and geothermal fields are associated with chemical effects of water-rock interaction. Surface outcrops of rocks from deeper levels in the crust, including exposures of lower crustal and mantle rocks, often display structures that formed by interaction of the rocks with a supercritical aqueous fluid at very high pT conditions. Understanding water-rock interaction is also of great importance to applied geology and geochemistry, particularly in areas such as geothermal energy, nuclear waste repositories and applied hydrogeology. The extremely wide-ranging research efforts on the universal water-rock interaction process is reflected in the wide diversity of themes presented at the regular International Symposia on Water-Rock Interaction (WRI). Because of the large and widespread interest in water-rock interaction, the European Union of Geosciences organized a special symposium on "water-rock interaction" at EUGI0, the biannual meeting in Strasbourg 1999 convened by the editors of this volume. In contrast to the regular WRI symposia addressed to the specialists, the EUG 10 "water-rock interaction" symposium brought the subject to a general platform This very successful symposium showed the way to the future of water-rock reaction research.

Many people have contributed to the production of this book, and I wish to acknowledge the following colleagues who have, over the past 15 years, contributed much discussion, preprints, thin sections, rock samples, and unpublished and/or difficult-to- obtain information: Steve Bergman, Roger Clement, Howard Coopersmith, Barry Dawson, Alan Edgar, Tony Erlank, Steve Haggerty, Barry Hawthorne, Bram Janse, Viktoria Komilova, Sergei Kostrovitskii, Henry Meyer, Peter Nixon, Nick Rock, Mike Skinner, Patricia Sheahan, Simon Shee, Barbara Scott Smith, Andy Spriggs, Ken Tainton, Larry Taylor, Nikolai Vladykin, Allan Woolley, and Peter Wyllie. Special thanks go to Henry Meyer, for providing many hours of microprobe time at Purdue University, and to Mike Skinner, for samples and the opportunity to examine the Anglo-American Research Laboratory collection of orangeites. Particular thanks are expressed to Ken Tainton for permission to quote data from his Ph.D. thesis. Particular gratitude is expressed to Sam Spivak for drafting and photographic work and to Anne Hammond for preparing many polished thin sections of these difficult rocks. Their dedication, skills, and attention to detail are greatly appreciated by the author. Others from Lakehead University who helped materially during the production of this work include Reino Viitala (thin sections), Alan MacKenzie (electron microscopy), and Shelley Moogk-Pickard (trace element analysis). Carl Hager is thanked for assistance in using the Purdue microprobe.

Zeolites, with their crystalline microporous structures, are cordial hosts to a wide variety of guests. However, it was the abrupt and unexpected departure of one of these guests (water) from a host (stilbite) on heating which led Cronstedt, in 1756, to coin the term "zeolite" (from the Greek meaning "boiling stone") to describe this material. Since that time, approximately 40 different naturally-occurring zeolites have been discovered on earth. Recent studies of meteorite compositions have shown that these guest-host materials (e. g. , sodalite) occur in other parts of the universe as well. However, it wasn't until the twentieth century that synthetic routes to zeolites and other non-aluminosilicate molecular sieves were discovered. In addition, with the development of X-ray diffraction and the various spectroscopies, better understanding of the nature of the cavities, cages, and channels of these materials has led to the industrial exploitation of their guest-host properties. The world of zeolites has now expanded into a greater than 2 billion pound per year business, with major applications in detergent formulations, catalysis, and as adsorbents and desiccants. Their economic impact is difficult to determine; however, the improvement in gasoline yields alone (from catalytic cracking) must account for hundreds ofbillions ofdollars in increased GDP. In this volume, we have brought together a sampling of recent developments in various areas of guest-host or inclusion chemistry in zeolites.

Volume 4 focuses on the vibrant research area centering around "Biomineralization" and its role in Nature and in biomimetic applications. With nearly 2700 references, 14 tables, and more than 140 illustrations, it is an essential resource for scientists working in the wide range from material sciences and inorganic biochemistry all the way through to medicine including the clinic.

In 18 stimulating chapters, written by 36 internationally recognized experts, "Biomineralization. From Nature to Application" highlights critically the interrelations between crystals and life. The volume covers the role of genes and genomes as well as enzymes on biomineralization processes; carbonate, sulfate, oxalate, and silicate biominerals; heavy metals, ferritin, and magnetotactic bacteria; the formation of bone, dentin, enamel, etc; the dynamics of biomineralization and biodemineralization; the mechanical design and bioinspired growth of mineralized tissues; and polymer-controlled biomimetic mineralizations for diverse applications.

Microscopy is a servant of all the sciences, and the microscopic examina tion of minerals is an important technique which should be mastered by all students of geology early in their careers. Advanced modern text books on both optics and mineralogy are available, and our intention is not that this new textbook should replace these but that it should serve as an introductory text or a first stepping-stone to the study of optical mineralogy. The present text has been written with full awareness that it will probably be used as a laboratory handbook, serving as a quick reference to the properties of minerals, but nevertheless care has been taken to present a systematic explanation of the use of the microscope as well as theoretical aspects of optical mineralogy. The book is therefore suitable for the novice either studying as an individual or participating in classwork. Both transmitted-light microscopy and reflected-light microscopy are dealt with, the former involving examination of transparent minerals in thin section and the latter involving examination of opaque minerals in polished section. Reflected-light microscopy is increasing in importance in undergraduate courses on ore mineralisation, but the main reason for combining the two aspects of microscopy is that it is no longer acceptable to neglect opaque minerals in the systematic petrographic study of rocks. Dual purpose microscopes incorporating transmitted- and reflected-light modes are readily available, and these are ideal for the study of polished thin sections."

Early in this century, the newly discovered x-ray diffraction by crystals made a complete change in crystallography and in the whole science of the atomic structure of matter, thus giving a new impetus to the development of solid-state physics. Crystallographic methods, pri marily x-ray diffraction analysis, penetrated into materials sciences, mol ecular physics, and chemistry, and also into many other branches of science. Later, electron and neutron diffraction structure analyses be came important since they not only complement x-ray data, but also supply new information on the atomic and the real structure of crystals. Electron microscopy and other modern methods of investigating mat ter-optical, electronic paramagnetic, nuclear magnetic, and other res onance techniques-yield a large amount of information on the atomic, electronic, and real crystal structures. Crystal physics has also undergone vigorous development. Many re markable phenomena have been discovered in crystals and then found various practical applications. Other important factors promoting the development of crystallog raphy were the elaboration of the theory of crystal growth (which brought crystallography closer to thermodynamics and physical chem istry) and the development of the various methods of growing synthetic crystals dictated by practical needs. Man-made crystals became increas ingly important for physical investigations, and they rapidly invaded technology. The production of synthetic crystals made a tremendous impact on the traditional branches: the mechanical treatment of mate rials, precision instrument making, and the jewelry industry.

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.

Microbial defacement and degradation of artistic or historic artifacts is a worldwide problem affecting all countries regardless of their history, geographical location, or economic conditions. This is the first comprehensive study of the role of microbial colonization on the degradation of different cultural artifacts (from buildings to books, wall paintings, textiles, sculptures and glass) and of the investigations into the compounds utilized to control microbial invasion. The book focuses on three main areas: the identification of the microorganisms which cause structural damage; methods to reduce or prevent microbial colonization and damage; and the use of microorganisms for the protection and bioremediation of cultural artifacts.

Feldspar minerals make up 60% of the crust of the Earth. They are stable in the upper mantle, and are so abundant in the crust that they form the basis of the classification of igneous rocks. At the surface, feldspars weather to form clay minerals which are the most important mineral constituent of soils. The articles in this book review the chemical reactions of feldspars over the whole sweep of pressure and temperature regimes in the outer Earth, and describe the fundamental aspects of crystal structure which underlie their properties. The book covers intracrystalline reactions, such as order-disorder transformations and exsolution, and transfer of stable and radiogenic isotopes, which can be interpreted to provide insights into the thermal history of rocks. It is suitable for final year undergraduates or research workers.

The reserves, or extractable fraction, of the fuel-mineral endowment are sufficient to supply the bulk of the world's energy requirements for the immediately forseeable future-well into the next century according to even the most pessimistic predictions. But increasingly sophisticated exploration concepts and technology must be employed to maintain and, if possible, add to the reserve base. Most of the world's fuel-mineral resources are in sedimentary rocks. Any procedure or concept that helps describe, under stand, and predict the external geometry and internal attributes of major sedimentary units can therefore contribute to discovery and recovery of coal, uranium, and petroleum. While conceding the desirability of renewable and nonpolluting energy supply from gravitational, wind, or solar sources, the widespread deployment of these systems lies far in the future-thus the continued commercial emphasis on conventional nonrenewable fuel mineral resources, even though their relative significance will fluctuate with time. For example, a decade ago the progilostications for uranium were uniformly optimistic. But in the early 1980s the uranium picture is quite sombre, although unlikely to remain permanently depressed. Whether uranium soars to the heights of early expectations remains to be seen. Problems of waste disposal and public acceptance persist. Fusion reactors may ultimately eliminate the need for uranium in power generation, but for the next few decades there will be continued demand for uranium to fuel existing power plants and those that come on stream. This book is, to some extent, a hybrid."