The Mjolnir impact structure was recognized in 1993 and included in the Earth Impact Database in 1996, based on the discoveries of unequivocal meteorite impact indicators such as shocked quartz, Ir-enrichments, possible glass remnants, fragments of nickel-rich iron oxides, in addition to the convincing complex crater shape of the structure. This book presents the geological and geophysical history of the Barents Sea region along with the discovery of the Mjolnir impact crater. We place the Mjolnir event into the geological framework of the region and present elaborative numerical models of its formation and associated tsunami generation. The book represents an update and synthesis as well as the complete compilation of the Mjolnir crater studies. "

Radiocarbon After Four Decades: An Interdisciplinary Perspective commemorates the 40th anniversary of radiocarbon dating. The volume presents discussions of every aspect of this dating technique, as well as chronicles of its development and views of future advancements and applications. All of the 64 authors played major roles in establishment, development or application of this revolutionary scientific tool. The 35 chapters provide a solid foundation in the essential topics of radiocarbon dating: Historical Perspectives; The Natural Carbon Cycle; Instrumentation and Sample Preparation; Hydrology; Old World Archaeology; New World Archaeology; Earth Sciences; and Biomedical Applications.

Sediment-hosted deposits are the main source of zinc and lead. In this volume, the reader will find the most recent developments in research including: - Fluid migration leading to formation of Zn-Pb ores in sedimentary basins. Relationships to orogenic events and to geothermic anomalies - Transport of metals and precipitation mechanisms. The role played by fluid mixing, fluid-rock reaction, organic matter, and thiosulfates - Paleomagnetic dating of ore deposits - The association of Mississippi Valley-type ore deposits to diapiric salt structures - Geochemical investigations applied to exploration for sediment-hosted Zn-Pb deposits - Economic aspects. The broad geographical coverage is an additional aspect which will interest both researchers and explorationists.

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."

1. THE SEMIOTIC CHARACTER OF ABORIGINAL SIGN LANGUAGES In our culture, language, especially in its spoken manifestation, is the much vaunted hallmark of humanity, the diagnostic trait of man that has made possible the creation of a civilization unknown to any other terrestrial organism. Through our inheritance of a /aculte du langage, culture is in a sense bred inta man. And yet, language is viewed as a force wh ich can destroy us through its potential for objectification and classification. According to popular mythology, the naming of the animals of Eden, while giving Adam and Eve a certain power over nature, also destroyed the prelinguistic harmony between them and the rest of the natural world and contributed to their eventual expulsion from paradise. Later, the post-Babel development of diverse language families isolated man from man as weIl as from nature (Steiner 1975). Language, in other words, as the central force animating human culture, is both our salvation and damnation. Our constant war with words (Shands 1971) is waged on both internal and external battlegrounds. This culturally determined ambivalence toward language is particularly appar ent when we encounter humans or hominoid animals who, for one reason or another, must rely upon gestural forms of communication."

The present book is the outcome of an Advanced Study Institute meeting, which was held in Kallithea, Chalkidiki, in Northern Greece, from 12-25 May 1991 and attended by 69 delegates from 18 countries. The Institute brought together scientists, engineers and technologists currently involved in basic and applied research on the different aspects of flotation. The Institute covered subjects in four major areas of flotation: a) fundamentals; b) chemical technology aspects; c) mineral processing; and d) water and wastewater treatment. Apart from the papers reproduced in this volume, several short oral communications were also presented. Participants also had the opportunity to visit the Hellenic Chemical Products & Fertilizers Co. Ltd. mixed sulphides plant, in Chalkidiki. Conference participants, whose interest and research projects are in this broad field of science and engineering, provided a well-informed discussion of the problems encountered, as well as possible directions of future technological developments. It is hoped that this book is not only a good record of the presentations made (formal and informal), analyzing the state-of-the-art in flotation, but will also be helpful for students, scientists and technologists working in the fields of separation processes and in particular mineral processing and wastewater engineering. All the invited speakers and the participants made this summer school possible, worthwhile and enjoyable. The sponsorship by the NATO Scientific Affairs Division is gratefully ack nowledged. The Editors would like to thank the members of the Organizing Committee, Dr. B.A."

Ice composition has until now been mostly used for reconstructing the environment of the past. A great research effort is made today to model the climate system in which the ice cover at the earth sur face plays a prominent role. To obtain a correct model of the ice sheets, due attention must be paid to the physical processes operating at the interfaces, i. e. the boundary conditions. The idea behind the title of this book is that the study of ice composition can shed some light on the various processes operating at the ice bedrock and ice-ocean interfaces and more generally on glacier dy namics. The book is not intended as a treatise on some specialized topic of glaciology. It is mainly the product of the experience of the two authors gained over several years research on the subject. The two authors are both members of the same university department and personal friends. The book was prepared in the following way. After a first draft of the complete book had been written by the first author, it was put in the hands of the second. The final version sent to the publishers is therefore the result of ex tended discussion, while at the same time preserving the unity of style that would have been lost had the two authors written selected chapters of the book individually. The book is organized into two distinct parts."

Perhaps no dating method has the wide range of applicability as does the potassium argon dating method from either consideration of the ranges of ages which can be dated or the availability of suitable material to date. Minerals as young as tens of thousands of years to minerals billions of years old have been successfully dated. Many minerals retain for times of the order of billions of years the daughter, Ar40, and many minerals contain as a component K40 the parent element, potassium being a common element in the earth's crust. As a result, most rock contains at least one mineral which can be successfully dated by the potassium argon method. Even though this method has been applied for over fifteen years, there is as yet no work which summarizes the experimental techniques and the results available. The sixtieth birthday ofW. GENTNER, one of the pioneers in this field of research, is a suitable time to present such a summary.

In November, 1986, the Institution of Mining and Metallurgy held the 'Mining Latin AmericalMineria Latinoamericana' conference in Chile - a conference covering a broad range of topics relevant to South America and, in that sense, complementary to its regional 'Asian Mining' and 'African Mining' series of events. This first conference proved to be a resounding success and confirmed that Chile, in particular, and South America, in general, were indeed ideal for the Institution in the pursuit of its objective of disseminating information related to the international minerals industry. In relation to South America, the Chilean conference was followed, in 1988, by that entitled 'Silver - exploration, mining and treatment', * which was held in Mexico City; in February, 1995, Caracas will host the 'Mineral resources of VenezuelalRecursos minerales de Venezuela' conference, serious planning for which is under way as I write. The Institution of Mining and Metallurgy, in association with the Instituto de Ingenieros de Minas de Chile, Mineria Chilena and Latinomineria agreed that the second 'Mining Latin AmericalMineria Latinoamerica' conference should be held, again in Santiago, in May, 1994, on the occasion of the 1994 Expomin show, which had been been particularly successful in attracting visitors from mining countries worldwide in 1992 and which will continue, at two-yearly intervals, to the year 2000 and, no doubt, beyond.

In diamond alluvial deposits, the information about the spatial distribution of stone size is of crucial importance for the quantitative characterisation of the different areas of the deposit. In fact, the value of the diamond reserves depends strongly on the distribution of stone sizes: between two areas with the same grade, the most valuable is the one with larger stones. The geological genesis of the mineralization, related with the transport and deposition of stones in trapsites, can create separated spatial areas, corresponding to different stone size. To characterise these distinct areas, the non smooth transitions between them should be accounted for, in the estimation of internal properties. An extended version of zonal control of geostatistical estimation (Soares et ai, 1995) proposed in this paper, aims to characterising the classes of size histogram for each geological unit, avoiding the smooth effect. For this purpose the morphology of each geological unit is obtained by using two distinct criteria: i) first, the points of each unit are classified according to the local and global probabilities of belonging to each unit (Soares, 1992); ii) in a second classification, the optimization technique of Simulated Annealing is used to rearrange the pre-classified points in order to impose, in the final morphological maps, the spatial variability of experimental samples (Goovaerts, 1994). A case study of a diamond alluvial deposit with two geological units with distinct stone size histograms is presented.

This volume presents different studies carried out on induced seismicity, both from experimental and theoretical viewpoints. Several examples of seismic activity induced by underground nuclear explosions, impoundment of artificial reservoirs, and mining activities are given and discussed. Another important subject which is covered is earthquakes induced by other large earthquakes. Further, tectonic stress release in the immediate vicinity of an underground nuclear explosion is treated. The release produces aftershocks of small magnitude, usually for several weeks, occurring a few kilometers within the shot point. This phenomenon is of importance in the context of monitoring a Comprehensive Test Ban Treaty.

A. K. TURNER Department of Geology and Geological Engineering Colorado School of Mines Golden, Colorado 80401 USA Geology deals with three-dimensional data. Geoscientists are concerned with three dimensional spatial observations, measurements, and explanations of a great variety of phenomena. The representation of three-dimensional data has always been a problem. Prior to computers, graphical displays involved specialized maps, cross-sections, fence diagrams, and geometrical constructions such as stereonets. All were designed to portray three-dimensional relationships on two-dimensional paper products, and all were time consuming to develop. Until recently, computers were of little assistance to three-dimensional data handling and representation problems. Memory was too expensive to handle the huge amounts of data required by three-dimensional assessments; computational speeds were too slow to perform the necessary calculations within a reasonable time; and graphical displays had too Iowa resolution or were much too expensive to produce useful visualizations. Much experience was gained with two-dimensional geographic information systems (GIS), which were applied to many land-use management and resource assessment problems. The two-dimensional GIS field matured rapidly in the late 1980's and became widely accepted. The advent of the modern computer workstation, with its enhanced memory and graphical capabilities at ever more affordable prices, has largely overcome these earlier constraints.

The ideas of probability are all around us. Lotteries, casino gambling, the al most non-stop polling which seems to mold public policy more and more these are a few of the areas where principles of probability impinge in a direct way on the lives and fortunes of the general public. At a more re moved level there is modern science which uses probability and its offshoots like statistics and the theory of random processes to build mathematical descriptions of the real world. In fact, twentieth-century physics, in embrac ing quantum mechanics, has a world view that is at its core probabilistic in nature, contrary to the deterministic one of classical physics. In addition to all this muscular evidence of the importance of probability ideas it should also be said that probability can be lots of fun. It is a subject where you can start thinking about amusing, interesting, and often difficult problems with very little mathematical background. In this book, I wanted to introduce a reader with at least a fairly decent mathematical background in elementary algebra to this world of probabil ity, to the way of thinking typical of probability, and the kinds of problems to which probability can be applied. I have used examples from a wide variety of fields to motivate the discussion of concepts."

This text presents the results of the joint research initiative "Numercial Simulation in Tunneling." In doing so it provides a thorough guide to improving the safety and economy of tunnels by discussing the application of numerical simulation methods to assist tunnel engineers. Numerical simulation tools for the estimation of the required tunnel support and the required construction measures are described in this book. By using them, it is possible to study the impact on the construction and on the environment at the planning stadium and during construction. This will result in an improvement of the safety and economy of tunnels.

The interest and level of research into climate variability has risen dramatically in recent years, and major breakthroughs have been achieved in the understanding and modelling of seasonal to interannual climate variability and prediction. At the same time, the documentation of longer term variability and its underlying mecha nisms have progressed considerably. Within the European Commission's Environment and Climate research programs several important projects have been supported in these areas - including the "Dec adal and Interdecadal Climate variability Experiment" (DICE) which forms the basis of this book. Within the EC supported climate research, we see an increasing importance of research into climate variability, as is evidenced in the upcoming Fifth Framework Programme's Key Action on Global Change, Climate and Biodi versity. This is because of the obvious potential socio-economic benefits from sea sonal to decadal scale climate prediction and equally important for the fundamental understanding of the climate system to help improve the quality and reliability of future climate change and mankind's current interference with it. The DICE group has performed important and pioneering work, and we hope this book will receive the wide distribution and recognition it deserves. We wel come the contributions from distinguished researchers from US, Japan and Canada to the EC's DICE group towards completing the scope of the book and as an exam ple of international cooperation which is essential in such a high-level scientific endeavor."

A summary of past work and a description of new approaches to thinking about kriging, commonly used in the prediction of a random field based on observations at some set of locations in mining, hydrology, atmospheric sciences, and geography.

The subject of earthquake engineering has been the focus of my teaching and research for many years. Thus, when Mario Paz, the editor of this handbook, asked me to write a Foreword, I was interested and honored by his request. Worldwide, people are beginning to understand the severity of the danger to present and future generations caused by the destruction of the environment. Earthquakes pose a similar threat; thus, the proper use of methods for earthquake-resistant design and construction is vitally important for countries that are at high risk of being subjected to strong-motion earthquakes. Most seismic activity is the result of tectonic earthquakes. Tectonic earthquakes are very special events in that, although they occur frequently, their probability of becoming natural hazards for a specific urban area is very small. When a severe earthquake does occur near an urban area, however, its consequences are very large in terms of structural destruction and human suffering.

There are at least 48 identified prehistoric stone circles in Scotland. In truth, very little is known about the people who erected them, and ultimately about what the stone circles were for. Most stone circles are astronomically aligned, which has led to the modern debate about why the alignment was significant. The megaliths certainly represented an enormous co-operative effort, would at the very least have demonstrated power and wealth, and being set away from any dwellings probably served a ceremonial, or perhaps religious, purpose.
Observations at the site of the stone circles, of solar, lunar, and stellar events, have already cast light on some of the questions about the construction and use of ancient megalithic observatories.
In his capacity as manager of the Parks Department Astronomy Project, author Duncan Lunan designed and built the first astronomically aligned stone circle in Britain in over 3,000 years. 'The Stones and the Stars' examines the case for astronomical alignments of stone circles, and charts the development of a fascinating project with a strong scientific and historical background. The work was documented in detail by the artist and photographer Gavin Roberts, and this archive has been added to since - so an appropriate selection of illustrations will bring the project vividly to life."

Plate tectonics has significantly broadened our view of the dynamics of continental evolution, involving both the processes currently active at the surface and those extending deep into the interior of the Earth. Seismic anisotropy provides some of the most diagnostic evidence for mapping past and present deformation of the entire crustmantle system. This volume contains papers presented originally at an international workshop at the Chateau of Trest in the Czech Republic in 1996. This workshop brought together geophysicists and geologists who work in the field of observational and theoretical seismology, mineral and rock physics, gravity studies and geodynamic modelling. Topics include large-scale anisotropy of the Earth's mantle, mantle heterogeneity vs. anisotropy 3-D velocity and density structures and inferences on mantle dynamics, mineral and rock physics studies, and mathematical aspects of complex wave propagation.

A major area of interest in French geomorphology during the last quarter of a cen- tury has been to understand denudation chronologies and the legacies of environ- mental change in shield regions. The mechanisms and consequences on landform patterns of differential erosion in plutonic,metamorphic and related cover rocks have been approached from the double angle of structural landforms in the landscape and petrographical,mineralogical and geochemical analysis in the laboratory. The detailed study of layered igneous intrusions has been particularly helpful in making progress more generally in the understanding of crystalline landform configurations of base- ment terrains. The Laboratoire de Geographic Physique CNRS-URAiai. nowreformed as twin research units (Paris: CNRS-UMR8591,and Clermont-Ferrand: CNRS-UPRES- A6042), and itsprecursor research group at the Sorbonne under the guidance of Pierre Birot,constituted the spawning ground for French research on the geomorphology of basement terrains. Alain Godard masterminded much of the research synthesised in this volume,which isbased on apreviously publishededition in French. YannickLageat and Jean-Jacques Lagasquie have not only upheld the spirit of this school of geomor- phology but also introduced novel concepts and methods to the investigation of crys- talline terrains. They have also maintained geomorphological research abreast of con- temporarydevelopments in the geosciences. YanniGunnell translated the original text into English, adapted the figures and introduced a measure of editing, updating and explicating in order to make the volume more accessible - not only to a non franco- phone audience, but to an audience unfamiliarwith the intellectual undercurrents and 30 years.

Shear waves and closely related interface waves (Rayleigh, Stoneley and Scholte) play an important role in many areas of engineering, geophysics and underwater acoustics. In some cases interest is focused on large-amplitude waves of low frequency such as those associ ated with earthquakes and nuclear explosions; in other cases low amplitude waves, which have often travelled great distances through the sediment, are of interest. Both low and high frequency shear and interface waves are often used for seafloor probing and sediment characterization. As a result of the wide spectrum of different interests, different disciplines have developed lines of research and a literature particularly suited to their own problems. For example water-column acousticians view the seafloor sediment as the lower boundary of their domain and are interested in shear and interface waves in the near bottom sediments mainly from the standpoint of how they influence absorption and reflection at this boundary. On the other hand, geophysicists seeking deep oil deposits are interested in the maximum penetration into the sediments and the tell-tale characteristics of the seismic waves that have encountered potential oil or gas bearing strata. In another area, geotechnical engineers use shear and interface waves to study soil properties necessary for the design and the siting of seafloor structures.

The contributions published in this volume are the re- sults of the NATO Advanced Research Workshop "Improvement of Joint Interpretation of Geophysical and Geological Data", which took place in Gradisca d'Isonzo in October 1987 and February 1988. Modern computer techniques were applied for geoscien- tific studies in a new dimension. 45 scientists from 7 Euro- pean countries, Canada and the united states of America par- ticipated in the workshop. Interactive discussions and modeling improved the understanding of the very complex structure of the investigated area. We thank all contributors, but especially those pub- lishing in this volume, for their active participation to ensure the success of the meetings. Not to forget to mention the groups of assistants from the Istituto di Minere e Geo- fisica Applicata of the University of Trieste and from the Institute of Geophysics of the Freie Universitat Berlin. Many thanks for their help around the clock. However, a major prerequisite for this success was given by the hospitality of the international Centre for Applied Sciences (ICAS) in the wonderful restored ancient pallazzi Torriani and Pretuna of the town of Gradisca d'Isonzo. Thus, we are thankful to the president of ICAS, Dr. H.R. Dahlafi, and to the town of Gradisca d'Isonzo, especially to the mayor, Signore Travan. The studies carried out in Gradisca d'Isonzo had been supported by a grant of the NATO Scientific Affairs Division and we express our thanks to Dr. L. da Cunha as a steady partner in the background.

In this unique volume, renowned experts discuss the applications of fractals in petroleum research-offering an excellent introduction to the subject. Contributions cover a broad spectrum of applications from petroleum exploration to production. Papers also illustrate how fractal geometry can quantify the spatial heterogeneity of different aspects of geology and how this information can be used to improve exploration and production results.

This is an extensive revision of a book that I wrote over ten years ago. My purpose then has remained unchanged: to introduce the concepts and methods of spatial statistics to geologists and engineers working with oil and gas data. I believe I have accomplished more than that; just as I learned the basics of variography and kriging from books for mining engineers, this book could be used by scientists from many fields to learn the basics of the subject. I have tried to adopt an introductory and practical approach to the subject, knowing that books that detail the theory are available. What I say and write comes from my own experience. As a geologist working in the public sector, I have had the privilege of using geostatistics in funded research, in answering service requests from industry, and in short courses. I have taught geostatistics in the university classroom, and advised graduate students in theses and dissertations. I have attempted to anticipate the needs and questions of the enquiring scientist because I was there myself, and know the kind of questions and concerns I had at the time I was trying to learn the subject.