I: Introductory Chapters.- 1. Introduction.- 1.1. The Big Bang: Forces, Particles and Isotopes.- 1.2. Supernovae, the Solar System and Isotopes.- 1.2.1. The Allende meteorite.- 1.2.2. Excess oxygen-16.- 1.2.3. Other anomalies.- 1.3. Elementary Particles.- 1.4. Elements.- 1.5. Radioactivity.- 1.6. Fractionation.- 1.7. Palaeothermometry.- 1.8. Unstable Atomic Nuclei.- 1.9. Beta Particles.- 1.10. Positron Decay.- 1.11. Electron Capture.- 1.12. Branched Decay.- 1.13. Alpha Decay.- 1.14. Nuclear Fission.- 1.15. Radioactive Decay.- 1.16. Decay Series.- 1.17. Radioactivity Units.- 1.18. Neutron Activation.- 1.19. Isotopic Translocation.- 2. Mass Spectrometry.- 2.1. Background.- 2.2. The Mass Spectrometer.- 2.3. Sample Preparation for Gas Isotope Mass Spectrometers.- 2.4. The Inlet System.- 2.5. The Ion Source.- 2.6. The Mass Analyser.- 2.7. Ionic Motions.- 2.8. Collector Systems and Ion Current Measurements.- 2.9. System Configuration Delta.- 2.10. Automatic Thermal Ionization Isotope Mass Spectrometer.- 2.11. Accelerator-Based Mass Spectrometry.- 2.12. Laser Mass Spectrometry.- 2.13. Ion Microprobes.- 2.14. Isotope Dilution.- II: Dating Methods.- 3. Uranium, Thorium, Lead Dating.- 3.1. Background.- 3.2. Geochemistry.- 3.3. Decay Series.- 3.4. Lead.- 3.5. U-Pb Concordia Diagrams.- 3.6. Concordia Models.- 3.7. U-Pb, Th-Pb, Pb-Pb Isochrons.- 3.8. Common-Lead Dating.- 3.9. Anomalous Leads.- 3.10. Multistage Leads.- 3.11. Whole-Rock Dating.- 3.12. Lead in Feldspars.- 3.13. Recent Advances.- 4. Rubidium-Strontium Dating.- 4.1. Background.- 4.2. Geochemistry.- 4.3. Dating Methodology.- 4.4. Isochrons.- 4.5. Mixtures.- 4.6. Fictitious Isochrons.- 4.7. Strontium Through Geological Time.- 4.7.1. Chondrites and achondrites.- 4.7.2. The Moon.- 4.7.3. The isotope evolution of terrestrial strontium.- 4.7.4. The origin of granites.- 4.8. Strontium in Sedimentary Deposits.- 5. Potassium-Argon and Argon-40/Argon-39 Dating.- 5.1. Background.- 5.2. Theory and Assumptions in Potassium-Argon Dating.- 5.3. Thermal Loss of Argon During Metamorphism.- 5.4. Isochrons.- 5.5. Sedimentary Rocks.- 5.6. Mantle-Derived Argon.- 5.7. Geomagnetic Polarity Reversals.- 5.8. The Metamorphic Veil of R L. Armstrong.- 5.9. Precambrian Time Scale.- 5.10. Argon-40/Argon-39 Dating.- 5.11. Theory.- 5.12. Incremental Heating.- 5.13. Correlation of Argon Isotopes.- 5.14. Caveats.- 5.15. Developments.- 6. Carbon-14 Dating.- 6.1. Background.- 6.2. Discovery.- 6.3. Carbon-14 Dating.- 6.4. Isotope Fractionation.- 6.5. Analytical Methods.- 6.6. Carbonate Samples.- 7. Tritium Dating.- 7.1. Background.- 7.2. Tritium Dating.- 8. Other Dating Methods.- 8.1. Samarium-Neodymium Dating.- 8.1.1. Geochemistry.- 8.1.2. Assessment of ages.- 8.1.3. Neodymium through geological time.- 8.1.4. Recent advances.- 8.2. Rhenium-Osmium Dating.- 8.2.1. Geochemistry.- 8.2.2. Assessment of ages.- 8.2.3. Osmium through geological time.- 8.2.4. Common-osmium dating.- 8.2.5. The C-T iridium anomaly.- 8.3. Potassium-Calcium Dating.- 8.3.1. Calcium isotopes fractionation.- 8.3.2. Potassium-calcium dating approach.- 8.4. Calcium Diffusion Dating.- 8.4.1. Theory.- 8.4.2. Calculation of D’.- 8.5. Lutetium-Hafnium Dating.- 8.5.1. Geochemistry.- 8.5.2. Assessment of ages.- 8.5.3. Hafnium through geological time.- 8.6. Uranium Series Disequilibrium Dating.- 8.6.1. Ionium dating of deep sea sediments.- 8.6.2. The uranium-234-uranium-238 geochronometer.- 8.6.3. Thorium-230-uranium-238, thorium-230-uranium-234 dating.- 8.6.4. Ionium-protactinium dating.- 8.6.5. Lead-210 dating.- 8.7. Radiation-Damage Methods.- 8.7.1. Electron spin resonance.- 8.7.2. Thermoluminescence.- 8.7.3. Pleochroic haloes.- 8.7.4. Fission track dating.- III: Environmental Isotopes.- 9. Environmental Isotopes in the Atmosphere and Hydrosphere.- 9.1. Background.- 9.2. Stable Isotopes of Oxygen and Hydrogen in the Hydrosphere.- 9.3. Stratigraphy of Ice and Snow.- 9.4. Sea Water Isotopic Composition.- 9.5. Oceanic Palaeothermometry.- 9.6. Variation of ?18O in Sea Water.- 9.6.1. Biogenic silica.- 9.6.2. Biogenic phosphate.- 9.7. Geothermal Waters.- 9.8. Cosmogenic Radionuclides in the Hydrologic Cycle.- 9.9. Sediment Dating with Cosmogenic Radionuclides.- 9.9.1. Manganese nodules.- 9.9.2. Beryllium-10 in volcanics.- 9.10. Dating Ice Sheets and Groundwaters.- 9.10.1. Beryllium-10 and aluminium-26.- 9.10.2. Chlorine-36.- 9.10.3. Silicon-32.- 9.10.4. Argon-39.- 9.10.5. Krypton-81 and krypton-85.- 9.11. Exposure Ages of Terrestrial Rocks and Meteorites.- 9.12. Nitrogen.- 9.13. Sulphur.- 9.14. Strontium.- 9.14.1. Fresh-water carbonates.- 9.14.2. Oceans.- 9.15. Neodymium.- 9.16. Artificial Isotope Hydrology.- 10. Isotopes in the Biosphere.- 10.1. A Basis for Terrestrial Life.- 10.2. Biospheric Carbon.- 10.3. Total Dissolved Inorganic Carbon (TDC) in Natural Fresh Waters.- 10.4. ?13Cof Marine Planktonic and Particulate Organic Carbon.- 10.5. Kerogen and Proto-Kerogen ?13C in Marine Sediments.- 10.6. ?13C of Ocean Total Dissolved Carbon.- 10.7. Organic Material Degradation in Anoxic Porewaters.- 10.8. Carbonate Minerals and Carbon-Rich Sediments.- 10.9. Fossil Fuels.- 10.9.1. Coal and lead.- 10.9.2. Coal and sulphur.- 11. Isotopes in the Lithosphere.- 11.1. Oxygen in Rocks.- 11.2. Stony Meteorites and Lunar Rocks.- 11.3. Hydrothermal Ore Deposits.- 11.4. Volcanic Rocks and Batholiths.- 11.5. Oxygen and Hydrogen Isotope Compositions in Sedimentary Rocks.- 11.6. Oxygen in Metamorphosed Rocks.- 11.7. Nitrogen in Igneous Rocks.- 11.8. Sulphur in Igneous Rocks.- 11.9. Sulphide Ores.- 11.10. Native Sulphur.- 11.11. Precambrian Sedimentary Rocks.- 11.12. Carbon: Carbonatites, Diamonds.- 11.13. Carbon: Marble, Graphite, Calcite-Graphite Isotope Geothermometer.- 11.13.1. Calcite-graphite isotope geothermometer.- 12. Isotopes in Palaeoclimatology.- 12.1. Background.- 12.2. Oxygen Isotope Composition in the Past.- 12.3. Cretaceous Extinctions.- 12.4. Campanian-to-Palaeocene Palaeotemperature and Carbon Isotope Sequence.- 12.4.1. Surface temperatures.- 12.4.2. Bottom temperatures.- 12.4.3. Surface carbon isotopic values.- 12.4.4. Surface-to-bottom carbon isotope differences.- 12.5. Oxygen Isotopes in Neogene Molluscan Fossils and Quaternary Foraminifera.- 12.6. Comparison of Isotopes and Plankton in a Late Quaternary Core.- 12.7. Stratigraphical Uncertainty Arising from Bioturbation.- 12.8. Further Foraminiferal Work.- 12.9. Ostracods.- 12.10. Some Carbon-13/Carbon-12 Data.- 12.10.1. Changes in the oceanic carbon- 13/carbon-12 ratio during the last 140 000 years.- 12.10.2. The carbon-13/carbon-12 ratio now.- 12.11. ?13C and Animal Diets.- 13. Radioactive Waste.- 13.1. Background.- 13.2. Nuclear Power.- 13.3. Chernobyl, USSR.- 13.4. Sizewell, England.- 13.5. Probability of Nuclear Reactor Accidents.- 13.6. Nuclear Waste Disposal.- 13.7. Selection of Nuclear Waste Sites.- 13.8. Appropriate Geological Environments for Deep Underground Repositories for Nuclear Wastes in the UK.- 13.8.1. Inland basins.- 13.8.2. Seawardly dipping and off-shore sediments.- 13.8.3. Lower permeability basement under a sedimentary cover.- 13.8.4. Hard rocks in low-relief terrane.- 13.8.5. Small islands.- 13.9. Fast-Breeder Reactors.- 13.10. The Problem of 94239Pu.- 13.11. A Matter of Balance.- Appendixes.- 1. The Exchange of Oxygen Isotopes in Carbon Dioxide-Phosphoric Acid Systems.- 2. Concentration and Purification of Zircon.- 3. A Palaeotemperature Equation for Planktonic Foraminifera.- Author Index.