ALBERT

Description / Table of Contents: Contents: 1 The roots of isotope geology. - 2 The internal structure of atoms. - 3 Decay mechanisms of radioactive atoms. - 4 Radioactive decay and growth. - 5 Mass spectrometry. - 6 The K-Ar method of dating. - 7 The 40Ar/39Ar method of dating. - 8 The Rb-Sr method of dating. - 9 Isotope systematics in two-component mixtures. - 10 Isotope geology of strontium in meteorites and terrestrial igneous rocks. - 11 Isotope geology of strontium in sedimentary rocks. - 12 The Sm-Nd method of dating. - 13 Isotope geology of neodymium and strontium in igneous rocks. - 14 Isotope geology of neodymium in sedimentary rocks. - 15 The Lu-Hf method of dating. - 16 The Re-Os method of dating. - 17 The K-Ca method of dating. - 18 The U, Th-Pb methods of dating. - 19 The isotope geology of lead. - 20 The fission-track and other radiation -damage methods of dating. - 21 The U-series disequilibrium methods of dating. - 22 Cosmogenic carbon-14 and tritium. - 23 Cosmogenic radionuclides. - 24 Oxygen and hydrogen in the hydrosphere and the atmosphere. - 25 Oxygen and hydrogen in the lithosphere. - 26 Carbon. - 27 Nitrogen. - 28 Sulfur. - Appendix I The geological time scale for the Phanerozoic Eon. - Index

Description / Table of Contents: This volume was produced in response to the need for a comprehensive introduction to the continually evolving state of the art of synchrotron radiation applications in low-temperature geochemistry and environmental science. It owes much to the hard work and imagination of the devoted cadre of sleep-deprived individuals who blazed a trail that many others are beginning to follow. Synchrotron radiation methods have opened new scientific vistas in the earth and environmental sciences, and progress in this direction will undoubtedly continue. The organization of this volume is as follows. Chapter 1 (Brown and Sturchio) gives a fairly comprehensive overview of synchrotron radiation applications in low temperature geochemistry and environmental science. The presentation is organized by synchrotron methods and scientific issues. It also has an extensive reference list that should prove valuable as a starting point for further research. Chapter 2 (Sham and Rivers) describes the ways that synchrotron radiation is generated, including a history of synchrotrons and a discussion of aspects of synchrotron radiation that are important to the experimentalist. The remaining chapters of the volume are organized into two groups. Chapters 3 through 6 describe specific synchrotron methods that are most useful for single-crystal surface and mineral-fluid interface studies. Chapters 7 through 9 describe methods that can be used more generally for investigating complex polyphase fine-grained or amorphous materials, including soils, rocks, and organic matter. Chapter 2 (Shearer) reviews the behavior of Be in the Solar System, with an emphasis on meteorites, the Moon and Mars, and the implications of this behavior for the evolution of the solar system. Chapter 3 (Ryan) is an overview of the terrestrial geochemistry of Be, and Chapter 7 (Vesely, Norton, Skrivan, Majer, Kr·m, Navr·til, and Kaste) discusses the contamination of the environment by this anthropogenic toxin. Chapter 3 (Fenter) presents the elementary theory of synchrotron X-ray reflectivity along with examples of recent applications, with emphasis on in situ studies of mineral-fluid interfaces. Chapter 4 (Bedzyk and Cheng) summarizes the theory of X-ray standing waves (XSW), the various methods for using XSW in surface and interfaces studies, and gives a brief review of recent applications in geochemistry and mineralogy. Chapter 5 (Waychunas) covers the theory and applications of grazing-incidence X-ray absorption and emission spectroscopy, with recent examples of studies at mineral surfaces. Chapter 6 (Hirschmugl) describes the theory and applications of synchrotron infrared microspectroscopy. Chapter 7 (Manceau, Marcus, and Tamura) gives background and examples of the combined application of synchrotron X-ray microfluorescence, microdiffraction, and microabsorption spectroscopy in characterizing the distribution and speciation of metals in soils and sediments. Chapter 8 (Sutton, Newville, Rivers, Lanzirotti, Eng, and Bertsch) demonstrates a wide variety of applications of synchrotron X-ray microspectroscopy and microtomography in characterizing earth and environmental materials and processes. Finally, Chapter 9 (Myneni) presents a review of the principles and applications of soft X-ray microspectroscopic studies of natural organic materials. All of these chapters review the state of the art of synchrotron radiation applications in low temperature geochemistry and environmental science, and offer speculations on future developments. The reader of this volume will acquire an appreciation of the theory and applications of synchrotron radiation in low temperature geochemistry and environmental science, as well as the significant advances that have been made in this area in the past two decades (especially since the advent of the third-generation synchrotron sources). We hope that this volume will inspire new users to "see the light" and pursue their research using the potent tool of synchrotron radiation.

Description / Table of Contents: The scientific discoveries that have been made with noble gas geochemistry are of such a profound and fundamental nature that earth science textbooks should be full of examples. Surprisingly, this really is not so. The "first discoveries" include presolar components in our _ solar system, extinct radionuclides, primordial volatiles in the Earth, the degassing history of Mars, secular changes in the solar wind, reliable present day mantle degassing fluxes, the fluxes of extraterrestrial material to Earth, groundwater paleotemperatures and the ages of the oldest landscapes on Earth. Noble gas geochemistry has scored so many such "firsts" or "home runs" that it should permeate a lot of earth science thinking and teaching. Yet rather surprisingly it does not. Noble gas geochemistry also is a broader and more versatile field than almost any other area of geochemistry. It pervades cosmochemistry, Earth sciences, ocean sciences, climate studies and environmental sciences. Yet most modern Earth, planetary and environmental science departments do not consider noble gas geochemistry to be at the top of their list in terms of hiring priorities these days. Furthermore, with the exception of Ar geochronologists, noble gas geochemists are a surprisingly rare breed. Why is the above the case? Perhaps the reasons lie in the nature of the field itself. First, although noble gas geochemists work on big problems, the context of their data is often woefully under-constrained so that it becomes hard to make progress beyond the first order fundamental discoveries. Noble gas data are often difficult to interpret. Although some concepts are straightforward and striking in their immediate implications (e.g. mantle 3He in the oceans), others are to this day shrouded in lack of clarity. The simple reason for this is that in many situations it is only the noble gases that offer any real insights at all and the context of other constraints simply does not exist. Some examples of the big issues being addressed by noble gases are as follows and I have deliberately posed these as major unresolved questions that only exist because noble gas geochemistry has opened windows through which to view large-scale issues and processes that otherwise would be obscure. (1) Is the presolar noble gas component present in a tiny fraction of submicroscopic meteoritic C or is it ubiquitously distributed? (2) How did solar noble gases get incorporated into the Earth? (3) How did solar noble gases survive the protracted accretion of the Earth via giant impacts? (4) What is the origin of the noble gas pattern in the Earth's atmosphere? (5) Why are the Earth and Mars almost opposites in terms of the relative isotopic differences between atmosphere and mantle? (6) What is the Eresent source of Earth's primordial helium? Can we ignore the core? (7) What is the 2~e/ 2Ne of the mantle, how was it acquired and why is it different from the atmosphere? (8) How does one reconcile the stronlJ fractionation in terrestrial Xe with data for other noble gases? (9) How much radiogenic Ar should the Earth have? How well do we know KIU? (10) Are the light isotopes of Xe the same in the mantle and the atmosphere? If not, why not? (11) How are noble gases transported through the creeping solid earth? (12) How does one explain the heat - helium paradox? (13) How incompatible are the noble gases during melting? (14) How are atmospheric components incorporated into volcanic samples? (15) How are the excess air components incorporated into groundwater? (16) Why are continental noble gas paleotemperature records offset from oceanic temperature records? Noble gas data tell us that the Earth and solar system represent very complex environments. When we make our simple first order conclusions and models we are only at the tip of the iceberg of discoveries that are needed to arrive at a thorough understanding of the behavior of volatiles in the solar system. Who wants to hear that things are complicated? Who wants to hire in a field that will involve decades of data acquisition and analysis in order to sort out the solar system? Sadly, too few these days. This is the stuff of deep scientific giants and bold, technically difficult long-term research programs. It is not for those who prefer superficiality and quick, glamorous, slick answers. Noble gas geochemists work in many areas where progress is slow and difficult even though the issues are huge. This probably plays a part in the limited marketability of noble gas geochemistry to the nonspecialist. Second, noble gases is a technically difficult subject. That is, noble gas geochemists need to be adept 11t technique development and this has to include skills acquired through innovation in the lab. Nobody can learn this stuff merely with a book or practical guide. Reading Zen and the Art of Motorcycle Maintenance (by Robert Pirsig) would give you a clearer picture. This magnificent MSA-GS volume is going to be enormously useful but on its own it won't make anybody into a noble gas geochemist. Although the mass spectrometry principles are not complex, the tricks involved in getting better data are often self taught or passed on by working with individuals who themselves are pushing the boundaries further. Furthermore, much of the exciting new science is linked with technical developments that allow us to move beyond the current measurement capabilities. Be they better crushing devices, laser resonance time of flight, multiple collection or compressor sources - the technical issues are central to progress. Lastly, noble gas geochemists need a broad range of other skills in order to make progress. They have to be good at mass spectrometry as already stated. However, nowadays they also need to be able to understand fields as different as mantle geochemistry, stellar evolution, cosmochemistry, crustal fluids, oceanography and glaciology. They are kind of "Renaissance" individuals. Therefore, if you are thinking broadly about hiring scientists who love science and stand a good chance of making a major difference to our understanding of the solar system, earth and its environment - I would recommend you hire a really good noble gas geochemist. However, the results may take a while. If you want somebody who will crank out papers at high speed and quickly increase the publication numbers of your department then you may need to think about somebody else. The two are not mutually exclusive but think hard about what is really important. There was no short course associated with this volume, although an attempt was undertaken to get the volume printed in time for the V. M. Goldschmidt conference in Davos, Switzerland (mid-August 2002) at which there was a major symposium on noble gases.