This book is written as a practical field manual to effective. Each geolOgist has to develop his/her be used by geologists engaged in mineral explo own techniques and will ultimately be judged on ration. It is also hoped that it will serve as a text results, not the process by which these results and reference for students in Applied Geology were reached. In mineral exploration, the only courses of universities and colleges. The book 'right' way of doing anything is the way that aims to outline some of the practical skills that locates ore in the quickest and most cost-effective turn the graduate geologist into an explo manner. It is preferable, however, for an individ rationist: . It is intended as a practical 'how to' ual to develop his/her own method of operation book, rather than as a text on geological or ore after having tried, and become aware of, those deposit theory. procedures which experience has shown to work An explorationist is a professional who search well and which are generally accepted in indus try as good exploration practice. es for ore bodies in a scientific and structured way. Although an awkward and artificial term, The chapters of the book approximately fol this is the only available word to describe the low the steps which a typical exploration pro totality of the skills which are needed to locate gramme would go through. In Chapter 1, the and define economic mineralization."

The Thirteenth International Conference on Basement Tectonics was held on the campus of Virginia Polytechnic Institute and State University in Blacksburg, Virginia from June 2 -6, 1997. The oral presentations and discussions over three days covered a wide range of topics, and provided the international audience with a perspective on scientific efforts underway around the world. The conference participants were able to attend two separate field trips: (I) a pre-conference trip guided by Professor Robert Hatcher of the University of Tennessee, Knoxville, examined the Basement rocks in the North Carolina -Tennessee region of the Appalachian Mountains, and (2) a mid-conference field trip guided by A.K. Sinha, convener of the conference, allowed participants to examine the complex rock associations and structures of the> 1000 m.y. old basement rocks in Virginia. Both the field trip guidebooks and abstract volumes were published for the conference. The meeting brought together scientists from more than 14 countries. Their participation, and the fiscal success of the meeting would not have been possible without the support of the Department of Geological Sciences, the College of Arts and Sciences (VPI&SU) and the Basement Tectonics Association. Their support is gratefully acknowledged. As Chairman of the Organizing Committee, I would like to thank Margie Sentelle, Jay Thomas, Peter Welch, and Barry Robinson for the smooth operation of the conference.

Can a continuous growth of agriculture be achieved in the sub-Sahara region without inducing irreversible damage to the ecosystem? Until now, doubts have been expressed as to the actual capacity of the soils to sustain a desirable increase of production which can match the requirements of a fast-growing population. Thirty years of investigation and a renewed comprehensive interpretation of research data on soil fertility show that a sustainable agriculture growth could be a practical possibility in a savannah region.

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 matter investigations, including the main characteristics of all the methods, the most important problems and topics of mineral ogy, 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."

The present work. Authigenic Minerals in Sedimentary Rocks, is designed for the broad circle of lithologists, and also for the geologists and geochemists who are studying sedimentary rocks and ores. Its specific purpose is to stir up interest among lithologists and geologists in the geochemical environment associated with the formation of authigenic minerals in sedimentary rocks, to encourage work in tracing the sequence of formation of these min erals, and to direct attention to other genetic problems. The book by no means pretends to be a determinative atlas of the authigenic minerals in sedimentary rocks; its task is to draw the reader's attention to questions of origin and, at the same time, to equip him with systematic knowledge about the physical and, especially, the optical properties of these minerals. In addition, the simplified chemical reactions indicated in the book wiIl permit one to distinguish similar minerals, and will also allow him to detect various mineral deposits in the field. Another purpose of the book is to acquaint chemists and geochemists with the properties of the minerals they study in making chemical analyses, minerals that com monly occur as polymineralic aggregates in the samples that are examined."

It is the policy of the federal Canadian Forestry Service to sponsor research initiatives from the private sector that are judged to be pertinent to its mandate and offer particular promise towards the optimal management of Canadian forest resources. This book is based on such an initiative. It represents the philosophy of the author himself and is in no way constrained by the views of the sponsoring agency. Over the past two decades Dr J. A. C. Fortescue has become well known at a number of research centers throughout the world. He has pioneered the approach to environmental understanding that is comprehensively developed in this text. The limitations of traditional compartmentalized approaches are depre cated and the case is made for a holistic rethinking of basic concepts and princi ples. Landscape Geochemistry is the disciplinary outcome that gives expression to this rethinking. It may be viewed as the minimum scale of conceptual approach necessary in the environmental sciences to solve present-day problems and to exploit future opportunities."

The oceans cover about 72 percent of our planet (which is named for the remaining 28 percent). These oceans have fascinated and challenged the human race for centuries. In the past, the ocean had been used first as a source of food and later as a means of transportation. However, the oceans have recently become very important-they may offer a solution to many of our modern problems. For example, refuse from land is to be dumped into the ocean never to be seen again; fish and other biological resources are to be caught and used to meet the protein deficiency of the world; oil and gas from the continental shelf and perhaps deeper areas will eventually solve our energy problems. None ofthese examples is completely possible, and the at source offood and later as a means of transportation. However, the oceans social, and ecological problems in the marine environment. Countries are al ready planning how the oceans can be divided up, so that they will get their "fair share." Economists, politicians, and others are producing almost daily, optimistic or pessimistic views (depending upon your own viewpoint) about the ocean and its resources. Equally loud reports come from environ mentalists, conservationists, government sources, and oil companies con cerning the pollution and potential destruction of the ocean."

In May 1976 Lucian B. Platt organized a highly successful Penrose Confer ence on The Formation of Rock Cleavage at Bryn Mawr College in Penn sylvania, U. S. A. The meeting drew together about 70 specialists from both sides of the Atlantic and from Australasia, who contributed discussions on various aspects of rock cleavage and its formation. Even early in the meet ing it became clear to the participants that they lacked a common terminol ogy, that often the same technical word implied different things to different people and that observables and descriptors were loosely defined. In an at tempt to improve communication the present editors contacted about 190 workers after the conference with a view to compiling a set of photographs with captions to illustrate exactly what workers were talking about. As a re sult the compilation was published as a limited edition by an inexpensive offset process at the University of Tasmania. The success of that provisional edition of the Atlas of Rock Cleavage and the responses of the readers prompted us to make a more extensive collection of material, contact a wider range of workers and, with the support of Dr. Konrad Springer, to publish the present higher-quality reproduction of the contributors' plates."

Earth scientists, who have worked together for 6 years in the priority pro gram "Hydrogeochemical Processes in the Hydrological Cycle Within the Unsaturated and Saturated Zones," have summarized the results of their research in this volume. This is the occasion to take stock and then look ahead. The priority program was set up by the Senate of The Deutsche Forschungsgemeinschaft in October 1981. This was preceded by lengthy and careful preparation by a Program Committee, and was finally recom mended by the Senate Commission for Joint Research in Earth Sciences. The main aim was the interdisciplinary research of geochemical processes in natural systems in the total underground water cycle, whereby water pollution was not to be considered. Officially started on 1 September 1982, the program has received a grant of DM 10. 9 Mio. from the DFG, and this has enabled it to support a total of 50 projects. Although at the beginning, practice-oriented projects, which were funded elsewhere, were not to be included, many of the results are applicable. The four categories presented were investigated with vary ing intensity. An early concentration on certain representative fields of measurement and research areas proved to be the right approach - this avoided a waste of effort in other fields. During the period of the priority program, new and topical questions arose, e. g."

It seems almost trite to introduce this book by saying that man has been exploiting the intertidal zone for food for a long time. Just how long nobody knows for sure but the prehistoric inhabitants of Terra Amata, on the Mediterranean coast near Nice, ate marine intertidal animals at least 300 000 years ago. Similar impressive evidence, going back to at least 100000 years, exists for prehistoric man's consumption of intertidal animals along the South African coast. However, early man's dependence on intertidal resources probably goes back much further in time. During the last 2 million or so years temperate Eurasia experienced some 20 glaciations interspersed by warm equable periods. Different modes of life were open to man in colonizing the northern temperate zone. One was to become a "big-game" hunter, specializing, for example, on mammoths, the other to exploit marine intertidal resources. Of the two, probably the shoreline offered an easier environment for an original scavenging food-gatherer.

This book presents the results of the Third International Symposium on Observation of the Continental Crust through Drilling held in Mora and Orsa, Sweden, September 7 - 10, 1987. Volume 2 reviews new and general information on geology, geophysics, rock mechanics, geochemistry, drilling techniques and drilling problems in very deep holes of the FRG, USA and the Soviet Union. The proceedings are invaluable for earth scientists as well as for exploiters of geoenergy and other natural resources in the crust. Volume 1 summarizes the results of the Deep Gas Project in the Siljan impact structure, Sweden, including papers dealing with general aspects of astroblemes. It is of interest to all researchers working in the drilling industry and those interested in the problem of "deep gas."

In May of 1991, Victor Van Buren, who was then with Springer Verlag in New York City, asked us for timely topics in the earth sciences that would be appropriate for publication as a book. We all quickly agreed that recent interest and research activity on the role of organic acids in geological processes would make a timely book on this diverse and controversial topic. As coeditors, we outlined chapter topics for such a book that maintained a good balance between geological and geochemical interests. Specific authors were then sought for each of the chapter topics. We had exceptional success in getting leading researchers as authors, and their response was universally enthusiastic. This approach has been most gratifying in that it provides a cohesion and conciseness that is not always present in books representing compilations of papers from symposia. This book does not resolve the controver sies that exist regarding the significance of organic acids in geolog ical processes. However, it does present both sides of the controver sies in terms of available data and current interpretations. Readers may judge for themselves and envisage research necessary to resolve these controversies in the future. We thank the authors of this book for their participation, dedication, and cooperation. We are also grateful for support from Dr. Wolfgang Engel and his staff at Springer-Verlag (Heidelberg) in expediting the editing and publication of this book in a timely manner."

Key biogeochemical events in the ocean take place in less than a second, are studied in experiments lasting a few hours, and determine cycles that last over seasons or even years. Models of the controlling processes thus have to take into account these time scales. This book aims at achieving consensus among these controlling processes at all relevant time scales. It helps understand the global carbon cycle including the production and breakdown of solved organic matter and the production, sinking and breakdown of particles. The emphasis on considering all time scales in submodel formulation is new and of interest to all those working in global ocean models and related fields.

Remarks by JVS. Volumes 1 and 2 of Feldspar Minerals were published in 1974, but Volume 3 was not completed because I was forced to devote 3 years to the resolution of unforeseen problems in the construction of an ion probe. By 1977, the incomplete draft for Volume 3 had become obsolete because of the enormous advances in knowledge of feldspars, particularly those in lunar rocks and meteorites, and in both deep-seated and ancient terrestrial rocks. Furthermore, it soon became obvious that a completely new version of Feldspar Minerals was needed because of the important new results on the physical and chemical properties. I had kept up with the interesting but tedious chore of weekly reading of the incoming literature and maintenance of the files. By 1980, the intense day-to day pressure had gone from my research programs on lunar rocks and on the development of the ion microprobe as a quantitative geochemical instrument, and I began preparation of a second edition of Feldspar Minerals."

The contributions in this book were presented, orally or as posters, at the International Volcanological Congress held in New Zealand from 1 to 9 February 1986, the centenary year of the Tarawera eruption of 10 June 1886. More than 500 people, from 29 countries, attend ed the Congress. Most of these works formed part of Symposium 4, "Volcanic Hazards - Prediction and Assess ment," convened by J.H. Latter, R.R. Dibble, D.A. Swanson and C.G. Newhall. The collection represents over half of the published abstracts of Symposium 4, together with three papers given at the Symposium, which lacked abstracts, and two which were part of Symposium 1 on pyroclastic flow deposits. The contribu tions cover a good proportion of the volcanically active parts of the world, with Italy, Japan, the West Indies and the USA especially well represented. Mount Erebus, Vulcano and Rabaul are individual volcanoes which have been treated in particular detail. Unfor tunately, there are no chapters in the book dealing with Africa, the Atlantic islands (except Iceland), Hawaii, Central America (except Mexico), or South America (in spite of the major disaster at Nevado del Ruiz Volcano in 1985)."

The earth is seen as a dynamic body undergoing convection that is driven by its internal heat. The elucidation of the nature and evolution of the earth's lithosphere, that has provided all minerals and energy resources and the space in which we live is one of the principal motives behind the International Program "Dynamics and Evolution of the Lithosphere". A full understanding of the lithosphere requires further research especially on the continents and their margins: while the oceanic lithosphere cools and subsides as it flows away from the zone of upwelling, the continents, because of their different composition, remain buoyant in the mantle and survive over major portions of the earth's history. In trying to produce full confirmation of the validity of sea floor spreading and lithosphere subduction, Central Europe became more and more a crucial case. The deformation of continental plates is, however, more complex than that of the ocean-floor pattern. No discrete boundary exists between both the African and Eurasian plates. A number of unanswered questions arise e.g. whether African crust has overridden Europe, or European lithosphere collided in the ranges of Atlas of Algeria. The work of German, French and Suiss geologists accomplished much during this century. Central Europe has come to serve as a test site for the refinement of plate tectonics. A new understanding of the crustal dynamics of Central Europe was born with the aim of explaining its structural evolution.

Microbial mats are benthic communities of a variety of microorganisms. Their investigation requires multidisciplinary studies and close cooperation between microbiologists, biogeochemists, and geologists.
Reported here are recent advances in the study of structure, development and ecological relationships. The methodology described includes microsensors as well as new molecular techniques for the detection and identification of microorganisms. Increasing interest exists for applied aspects, e.g. the possibility to use natural or constructed microbial mats for the degradation of xenobiotics, for site remediation, etc.

How large is the natural variation in concentration of the various elements in different media? How do the oft-cited "World average concentrations" in different media compare with actual analytical data? How low a detection limit do I need to attain if I want to analyse for an element in soils, sediments, water or plants? All these questions and many more can be answered by using this unique reference book. It collates data on the most important properties and uses of all naturally occurring chemical elements. It combines these with data obtained from actual analyses of different sample media (soil, stream sediment, stream water, ground water, plants, human body fluids). This combination of facts and actual data makes this book suitable for learning and teaching applied geochemistry as well.

The drilling site of the KTB is located on the western margin of the Bohemian Massif, a few kilometers south of the structurally important Saxothur ing ian/Moldanubian boundary of the central European Hercynian orogene and several kilometers east of one of the most important Permian-Mesozoic strike-slip zones of central Europe, the Franconian line. The borehole will be drilled in the Moldanubian segment (Fig. 1). o -::: --. . . . . . . . -. . -. D Il1O, Fig. l: Geological map of the Central Europe Variscides and location of borehole From geographical and political points of view, the drill site is located in northern Bavaria in the Oberpfalz province near the towns of Windischeschenbach and Erbendorf about 40 km southeast of Bayreuth. TARGETS AND RESEARCH TOPICS 'The Continental Deep Drilling program of the Federal Republic of Germany (KTB) is a project of basic geoscientific research. The program and goals of this project have been set by a board of the Senate Commission on Geosciences of the German Research Foundation (DFG). The technical concept of the drilling, sampling, coring and logging programs corresponds to these goals. The upper limit of the budget of 450 million DM is approved by the Federal Ministry of Research and Development (Bundesministerium fuer Forschung und Technologie).

The first edition of this book was published in 1965 and its French translation in 1966. The revised second edition followed in 1967 and its Russian translation became available in 1969. Since then, many new petrographic observations and experimental data elucidat- ing reactions in metamorphic rocks have made a new approach in the study of metamorphic transformation desirable and possible. It is felt that this new approach, attempted in this book, leads to a better unders- tanding of rock metamorphism. The concept of metamorphic facies and subfacies considers asso- ciations of mineral assemblages from diverse bulk compositions as characteristic of a certain pressure-temperature range. As new petrographic observations accumulated, it became increasingly difficult to accommodate this information within a manageable framework of metamorphic facies and subfacies. Instead, it turned out that mineral assemblages due to reactions in common rocks of a particular composi- tion provide suitable indicators of metamorphic conditions. Metamorphic zones, defined on the basis of mineral reactions, very effectively display the evolution of metamorphic rocks. Thus the im- portance of reactions in metamorphic rocks is emphasized. Experimen- tal calibration of mineral reactions makes it possible to distinguish reac- tions which are of petrogenetic significance from those which are not. This distinction provides guidance in petrographic investigations un- dertaken with the object of deducing the physical conditions of metamorphism.

One of the fundamental objectives of physical geochemistry is to understand the evolution of geochemical systems from microscopic to regional and global scales. At present there seems to be a general recognition of the fact that internal properties of minerals record important aspects of the evolutionary history of their host rocks which may be unraveled by very fine scale observations. A major focus in the development of geochemical research in the last thirty years has been the application of classical thermodynamics to reconstruct the conditions at which the states of quenched mineralogical properties of rocks have equilibrated during the course of their evolution. While these works have funda mentally influenced our understanding ofthe physico-chemical history ofrocks, in recent years petrologists, mineralogists, and geochemists have been making greater efforts towards the application of kinetic theories in order to develop a better appreciation of the temporal details of geochemical processes. The present volume brings together a variety of current research on transport in systems of geochemical interest from atomic to outcrop scales. A major theme is atomic migration or diffusion, and its various manifestations on microscopic and macroscopic scales. Transport in the solid state is controlled by diffusion and is responsible for the states of atomic ordering and relaxation of composi tional zoning in minerals, development of compositional zoning during cooling, exsolution lamellae, and creep."

More than seventeen years have passed now since Glauco Gottardi and Ermano Galli 1 have published their remarkable book on "NATURAL ZEOLITES" where properties and features of naturally occuring phases then available have been compiled. Several new natural zeolites have been found since then, but also natural counterparts ofzeolites which have only been known as synthesis products. The natural formation conditions of zeolites could only be deduced and estimated from their geological environment at the time when NATURAL ZEOLITES has been published, as zeolite synthesis was mainly focused on procedures at low pressures such as those introduced by Barrer and co workers'. Natural zeolites, however, had only been obtained "occasionally" and systematic study to reconstruct these formation conditions has not been performed ever since. This book is focused on the synthesis of natural zeolites by simulating the natural synthesis conditions in the laboratory which are essentially different in means and results from those obtained by conventional synthesis methods. Although the synthesis in the laboratory has undoubtly a great number of advantages over nature such as the employment of proper precursors or the choice of pressure and temperature in a wide range, the synthesis time is very limited in respect to natural conditions: synthesis times ofyears or even tens ofyears which would be necessary to obtain synthesis results for some zeolites- e.g. at 4 DegreesC (deep sea conditions) are rather unrealistic.

Reviewers of the German edition of this book found that the text deals with facts and descriptions of limestones rather than with glo- bal speculations on facies models or large-scale sedimentation pat- terns. The book is neither a picture-book nor a recipe-book for facies interpretation of carbonates, but an attempt to summarize the present "state of the art" of a rather small but increasingly more im- portant part of geology. The book is written for advanced undergraduate and post-grad- uate students as well as for research workers and exploration geol- ogists who need rapid and intensive training in modern methods of microfacies analysis. The book should facilitate decisions about which methods to use in one's own investigations, and where to look for comparative studies. Microfacies interpretation of carbonate rocks can not rely solely on the investigation of sedimentological and paleontological thin- section data, but must also consider geological and palecological cri- teria. It is beyond the scope of this book to describe all of these as- pects. However, broader applications are indicated in the chapters dealing with the relationships between geochemical as well as physi- cal data and the depositional and diagenetic fabric oflimestones.

As this excellent book demonstrates, the study of comets has now reached the fas cinating stage where we understand comets in general simple tenns while, at the same time, we are uncertain about practically all the details of cometary nature, structure, processes, and origin. In every aspect, even including dynamics, a choice among several or many competing theories is made impossible simply by the lack of detailed knowledge. The space missions, snapshot studies of two comets, partic ularly the one that immortalizes the name of Sir Edmund Halley, have produced a huge mass of valuable new infonnation and a number of surprises. Nonetheless, we face the tantalizing realization that we have obtained only a fleeting glance at two of perhaps a hundred billion (lOll) or more comets with possibly differing natures, origins, and physical histories. To my personal satisfaction, comets seem to have discrete nuclei made up of dirty snowballs, as I concluded four decades ago, but perhaps they are more like frozen rubbish piles.