Lectures In Isotope Geology

Our colleagues from the French-speaking parts of Switzerland - the Suisses romands - and above all the committee of the 3rd Cycle, e Earth Sciences (3 Cycle, Sciences de la Terre) honored us by asking us to give a course on Isotope Geology for the year 1977. The course, entitled Evaluation et Interpretation des Donnees Isotopiques (eval uation and Interpretation of Isotopic Data), was intended to inform earth scientists, graduate and postgraduate, from the western Swiss Universities on the subject of Isotope Geology. Such courses usually consist of two parts: lectures and excursions. Thus, in March 1977, we gave such a two-week course at the Miner alogical Institute of the University of Berne. The first week was devoted essentially to the methods of dating, the second week to the behavior of stable isotopes. In July 1977, on the occasion of an excursion to the Central and Western Alps, we were able to demonstrate our results. Guest professors were invited to make contributions to the course.

This wide-ranging text in isotope geology/geoscience allows students to integrate material taught in various courses into a unified picture of the earth sciences. Gives a rational exposition of the principles used in the interpretation of isotopic data and shows how such interpretations apply to the solution of geological problems. Current with references up to 1985, chapters in this edition have been revised, and new chapters on Sm-Nd, Lu-Hf, Re-Os, and K-Ca decay schemes and cosmogenic radionuclides have been added. Data summaries and references have been expanded. Also includes problems for student study and abundant line drawings with explanatory captions.

Accelerating progress in the application of radioactive and stable isotope analysis to a varied range of geologicla and geochemical problems in geology has required a complete revision of Isotopes in the Earth Sciences, published in 1988. This new book comprises four parts: the first introduces isotopic chemistry and examines mass spectroscopic methods; the second eeals with radiometric dating methods. Part Three examines the importance of isotopes in climato-environmental studies, and increasingly significant area of research. The last part looks at extra-terrestrial matter, geothermometry and the isotopic geochemistry of the Earth's lithosphere. Post-graduate and post-doctoral researchers in geochemistry, as well as final year undergraduates in the earth and environmental sciences, will find Radioactive and Stable Isotope Geology an invaluable, uo-to-date and thorough treatment of the theory and practice of isotopie geology.

Since the end of World War II isotope geology has grown into a diversi fied and complex discipline in the earth sciences. It has progressed by the efforts of a relatively small number of specialists, many of whom are physi cists, chemists, or mathematicians who were attracted to the earth sciences by the opportunity to measure and to interpret the isotopic compositions of certain chemical elements in geological materials. The phenomenal growth of isotope geology during the last 25 years is an impressive indi cation of the success of their efforts. We have now entered into a new phase of development of isotope geology which emphasizes the application of the new tools to the solution of specific problems in the earth and planetary sciences. This requires the active participation of a new breed of geologists who understand the nature and complexity of geological problems and can work toward their solution by a thoughtful application of the principles of isotope geology. It is there fore necessary to explain these principles to earth scientists at large to enable them to make use of the new information which isotope geology can offer them.

This book provides a comprehensive introduction to radiogenic and stable isotope geochemistry. Beginning with a brief overview of nuclear physics and nuclear origins, it then reviews radioactive decay schemes and their use in geochronology. A following chapter covers the closely related techniques such as fission-track and carbon-14 dating. Subsequent chapters cover nucleosynthetic anomalies in meteorites and early solar system chronology and the use of radiogenic isotopes in understanding the evolution of the Earth’s mantle, crust, and oceans. Attention then turns to stable isotopes and after reviewing the basic principles involved, the book explores their use in topics as diverse as mantle evolution, archeology and paleontology, ore formation, and, particularly, paleoclimatology. A following chapter explores recent developments including unconventional stable isotopes, mass-independent fractionation, and isotopic ‘clumping’. The final chapter reviews the isotopic variation in the noble gases, which result from both radioactive decay and chemical fractionations.

Do we actually understand geologic processes? New technology brings new inf- mation and perceptions, which sometimes overturn imaginations based on simple observation and estimation, in conjunction with common sense inference. In 1902– 1904,PierreCurieandErnestRutherford?rstformulatedtheideaofusingradioactive transformation of nuclides as a geologic chronometer. After a century of working with such tools, geology has advanced from a descriptive science to an analytic s- encethatformulatesconclusionsbasedonexactvalues.Thetechnologyofradiogenic isotope geology has created a branch of science that considers the Earth as a planet generated within a Solar system and studies the subsequent evolution of geologic processes that has resulted in the present formation of our planet’s continents and oceans. The physicist Vitaly Ginsburg, Nobel Prize laureate, wrote recently: “If Kepler had been given information on orbital parameters of planets with modern precision, he would not have been able to formulate his laws”. Indeed, after development of laws of celestial mechanics, methods of measurements became so advanced and such numerous secondary distortion effects were found that to describe an orbit of a cosmic body by a curve of the second order would appear impossible. But it does not mean that Kepler’s laws are “cancelled”; they still occupy an honorable place in courses on celestial mechanics. A reasonable division into basic and secondary phenomena is accepted and the latter are entered as variations in the basic equations.

This book takes the reader through the complete weathering cycle, from the continents to the oceans, from the perspective of modern radiogenic isotope geochemistry. Topics include surface weathering, fluvial processes, environmental pollution, oceanography and paleoceanography, sedimentary mineral diagenesis and radiometric dating, thus bridging the gap between processes acting on the Earth today and the geological record. Extensive use is made of carefully selected case studies, both pioneering and state-of-the-art. This book enables the reader to critically assess previous work from the literature as well as encouraging already established researchers to apply the most modern isotopic approaches to their particular field of study.