Strontium Isotope 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.

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.

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.

Environmental Tracers in Subsurface Hydrology synthesizes the research of specialists into a comprehensive review of the application of environmental tracers to the study of soil water and groundwater flow. The book includes chapters which cover ionic tracers, noble gases, chlorofluorocarbons, tritium, chlorine-36, oxygen-18, deuterium, and isotopes of carbon, strontium, sulphur and nitrogen. Applications of the tracers include the estimation of vertical and horizontal groundwater velocities, groundwater recharge rates, inter-aquifer leakage and mixing processes, chemical processes and palaeohydrology. Practicing hydrologists, soil physicists and hydrology professors and students will find the book to be a valuable support in their work.

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.

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.

The Encyclopedia is a complete and authoritative reference work for this rapidly evolving field. Over 200 international scientists, each experts in their specialties, have written over 330 separate topics on different aspects of geochemistry including geochemical thermodynamics and kinetics, isotope and organic geochemistry, meteorites and cosmochemistry, the carbon cycle and climate, trace elements, geochemistry of high and low temperature processes, and ore deposition, to name just a few. The geochemical behavior of the elements is described as is the state of the art in analytical geochemistry. Each topic incorporates cross-referencing to related articles, and also has its own reference list to lead the reader to the essential articles within the published literature. The entries are arranged alphabetically, for easy access, and the subject and citation indices are comprehensive and extensive. Geochemistry applies chemical techniques and approaches to understanding the Earth and how it works. It touches upon almost every aspect of earth science, ranging from applied topics such as the search for energy and mineral resources, environmental pollution, and climate change to more basic questions such as the Earth’s origin and composition, the origin and evolution of life, rock weathering and metamorphism, and the pattern of ocean and mantle circulation. Geochemistry allows us to assign absolute ages to events in Earth’s history, to trace the flow of ocean water both now and in the past, trace sediments into subduction zones and arc volcanoes, and trace petroleum to its source rock and ultimately the environment in which it formed. The earliest of evidence of life is chemical and isotopic traces, not fossils, preserved in rocks. Geochemistry has allowed us to unravel the history of the ice ages and thereby deduce their cause. Geochemistry allows us to determine the swings in Earth’s surface temperatures during the ice ages, determine the temperatures and pressures at which rocks have been metamorphosed, and the rates at which ancient magma chambers cooled and crystallized. The field has grown rapidly more sophisticated, in both analytical techniques that can determine elemental concentrations or isotope ratios with exquisite precision and in computational modeling on scales ranging from atomic to planetary.