Geochemistry by McSween, Harry Y. -- Read -- Imperial Library of Trantor

Index

Cover Half title Title Copyright Dedication Contents Preface to the Second Edition 1. Introducing Concepts in Geochemical Systems

Overview What Is Geochemistry?

Historical Overview Beginning Your Study of Geochemistry

Geochemical Variables Geochemical Systems Thermodynamics and Kinetics An Example: Comparing Thermodynamic and Kinetic Approaches Notes on Problem Solving Suggested Readings Problems

2. How Elements Behave

Overview Elements, Atoms, and the Structure of Matter

Elements and the Periodic Table The Atomic Nucleus and Isotopes The Basis for Chemical Bonds: The Electron Cloud Size, Charge, and Stability Elemental Associations

Bonding

Perspectives on Bonding Structural Implications of Bonding Retrospective on Bonding

Summary Suggested Readings Problems

3. A First Look at Thermodynamic Equilibrium

Overview Temperature and Equations of State Work The First Law of Thermodynamics Entropy and the Second Law of Thermodynamics

Entropy and Disorder

Reprise: The Internal Energy Function Made Useful Auxiliary Functions of State

Enthalpy The Helmholtz Function Gibbs Free Energy

Cleaning Up the Act: Conventions for E, H, F, G, and S Composition as a Variable

Components Changes in E, H, F, and G Due to Composition

Conditions for Heterogeneous Equilibrium

The Gibbs-Duhem Equation

Summary Suggested Readings Problems

4. How to Handle Solutions

Overview What Is a Solution?

Crystalline Solid Solutions Amorphous Solid Solutions Melt Solutions Electrolyte Solutions Gas Mixtures

Solutions That Behave Ideally Solutions That Behave Nonideally Activity in Electrolyte Solutions

The Mean Salt Method The Debye-Hückel Method

Solubility

The Ionic Strength Effect The Common Ion Effect Complex Species

Summary Suggested Readings Problems

5. Diagenesis: A Study in Kinetics

Overview What Is Diagenesis? Kinetic Factors in Diagenesis

Diffusion Advection

Kinetics of Mineral Dissolution and Precipitation The Diagenetic Equation Summary Suggested Readings Problems

6. Organic Matter and Biomarkers: A Different Perspective

Overview Organic Matter in the Global Carbon Cycle Organic Matter Production and Cycling in the Oceans Fate of Primary Production: Degradation and Diagenesis Factors Controlling Accumulation and Preservation

Preservation by Sorption Degradation in Oxic Environments Diagenetic Alteration

Chemical Composition of Biologic Precursors

Carbohydrates Proteins Lipids Lignin

Biomarkers Application of Biomarkers to Paleoenvironmental Reconstructions

Alkenone Temperature Records Amino Acid Racemization

Summary Suggested Readings Problems

7. Chemical Weathering: Dissolution and Redox Processes

Overview Fundamental Solubility Equilibria

Silica Solubility Solubility of Magnesian Silicates Solubility of Gibbsite Solubility of Aluminosilicate Minerals

Rivers as Weathering Indicators Agents of Weathering

Carbon Dioxide Organic Acids

Oxidation-Reduction Processes

Thermodynamic Conventions for Redox Systems Eh-pH Diagrams Redox Systems Containing Carbon Dioxide Activity-Activity Relationships: The Broader View

Summary Suggested Readings Problems

8. The Oceans and Atmosphere as a Geochemical System

Overview Composition of the Oceans

A Classification of Dissolved Constituents Chemical Variations with Depth

Composition of the Atmosphere Carbonate and the Great Marine Balancing Act

Some First Principles Calcium Carbonate Solubility Chemical Modeling of Seawater: A Summary

Global Mass Balance and Steady State in the Oceans

Examining the Steady State How Does the Steady State Evolve? Box Models Continuum Models A Summary of Ocean-Atmosphere Models

Gradual Change: The History of Seawater and Air

Early Outgassing and the Primitive Atmosphere The Rise of Oxygen

Summary Suggested Readings Problems

9. Temperature and Pressure Changes: Thermodynamics Again

Overview What Does Equilibrium Really Mean? Determining When a System Is in Equilibrium

The Phase Rule Open versus Closed Systems

Changing Temperature and Pressure

Temperature Changes and Heat Capacity Pressure Changes and Compressibility Temperature and Pressure Changes Combined

A Graphical Look at Changing Conditions: The Clapeyron Equation Reactions Involving Fluids Raoult’s and Henry’s Laws: Mixing of Several Components Standard States and Activity Coefficients Solution Models: Activities of Complex Mixtures Thermobarometry: Applying What We Have Learned Summary Suggested Readings Problems

10. Picturing Equilibria: Phase Diagrams

Overview G-X2 Diagrams Derivation of T-X2 and P-X2 Diagrams T-X2 Diagrams for Real Geochemical Systems

Simple Crystallization in a Binary System: CaMgSi2O6-CaAl2Si2O8 Formation of a Chemical Compound in a Binary System: KAlSi2O6-SiO2 Solid Solution in a Binary System: NaAlSi3O8-CaAl2Si2O8 Unmixing in a Binary System: NaAlSi3O8-KAlSi

Thermodynamic Calculation of Phase Diagrams Binary Phase Diagrams Involving Fluids P-T Diagrams Systems with Three Components Summary Suggested Readings Problems

11. Kinetics and Crystallization

Overview Effect of Temperature on Kinetic Processes Diffusion Nucleation

Nucleation in Melts Nucleation in Solids

Growth

Interface-Controlled Growth Diffusion-Controlled Growth

Some Applications of Kinetics

Aragonite — Calcite: Growth as the Rate-Limiting Step Iron Meteorites: Diffusion as the Rate-Limiting Step Bypassing Theory: Controlled Cooling Rate Experiments Bypassing Theory Again: Crystal Size Distributions

Summary Suggested Readings Problems

12. The Solid Earth as a Geochemical System

Overview Reservoirs in the Solid Earth

Composition of the Crust Composition of the Mantle Composition of the Core

Fluxes in the Solid Earth

Cycling between Crust and Mantle Heat Exchange between Mantle and Core Fluids and the Irreversible Formation of Continental Crust

Melting in the Mantle

Thermodynamic Effects of Melting Types of Melting Behavior Causes of Melting

Differentiation in Melt-Crystal Systems

Fractional Crystallization Chemical Variation Diagrams Liquid Immiscibility

The Behavior of Trace Elements

Trace Element Fractionation during Melting and Crystallization Compatible and Incompatible Elements

Volatile Elements

Crust and Mantle Fluid Compositions Mantle and Crust Reservoirs for Fluids Cycling of Fluids between Crust and Mantle

Summary Suggested Readings Problems

13. Using Stable Isotopes

Overview Historical Perspective What Makes Stable Isotopes Useful? Mass Fractionation and Bond Strength Geologic Interpretations Based on Isotopic Fractionation

Thermometry Isotopic Evolution of the Oceans Fractionation in the Hydrologic Cycle Fractionation in Geothermal and Hydrothermal Systems Fractionation in Sedimentary Basins Fractionation among Biogenic Compounds Isotopic Fractionation around Marine Oil and Gas Seeps

Summary Suggested Readings Problems

14. Using Radioactive Isotopes

Overview Principles of Radioactivity

Nuclide Stability Decay Mechanisms Rate of Radioactive Decay Decay Series and Secular Equilibrium

Geochronology

Potassium-Argon System Rubidium-Strontium System Samarium-Neodymium System Uranium-Thorium-Lead System Extinct Radionuclides Fission Tracks

Geochemical Applications of Induced Radioactivity

Neutron Activation Analysis 40Argon-39 Argon Geochronology Cosmic-Ray Exposure

Radionuclides as Tracers of Geochemical Processes

Heterogeneity of the Earth’s Mantle Magmatic Assimilation Subduction of Sediments Isotopic Composition of the Oceans Degassing of the Earth’s Interior to Form the Atmosphere

Summary Suggested Readings Problems

15. Stretching Our Horizons: Cosmochemistry

Overview Why Study Cosmochemistry? Origin and Abundance of the Elements

Nucleosynthesis in Stars Cosmic Abundance Patterns

Chondrites as Sources of Cosmochemical Data Cosmochemical Behavior of Elements

Controls on Cosmochemical Behavior Chemical Fractionations Observed in Chondrites

Condensation of the Elements

How Equilibrium Condensation Works The Condensation Sequence Evidence for Condensation in Chondrites

Infusion of Matter from Outside the Solar System

Isotopic Diversity in Meteorites A Supernova Trigger? The Discovery of Stardust in Chondrites

The Most Volatile Materials: Organic Compounds and Ices

Extraterrestrial Organic Compounds Ices—The Only Thing Left

A Time Scale for Creation Estimating the Bulk Compositions of Planets

Some Constraints on Cosmochemical Models The Equilibrium Condensation Model The Heterogeneous Accretion Model The Chondrite Mixing Model Planetary Models: Cores and Mantles

Summary Suggested Readings Problems

Appendices

Appendix A: Mathematical Methods Appendix B: Finding and Evaluating Geochemical Data Appendix C: Numerical Values of Geochemical Interest

Glossary Index

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