Geochemistry / William M. White

Incluye bibliografía e índice temático: páginas 915-939

Preface.. About the companion website.. Chapter 1: Introduction.. 1.1 Introduction.. 1.2 Beginnings.. 1.3 Geochemistry in the twenty-first century.. 1.4 The philosophy of science.. 1.4.1 Building scientific understanding.. 1.4.2 The scientist as skeptic.. 1.5 Elements, atoms, crystals, and chemical bonds: some chemical fundamentals.. 1.5.1 The periodic table.. 1.5.2 Electrons and orbits.. 1.5.3 Some chemical properties of the elements.. 1.5.4 Chemical bonding.. 1.5.5 Molecules, crystals, and minerals.. 1.6 A brief look at the Earth.. 1.6.1 Structure of the Earth.. 1.6.2 Plate tectonics and the hydrologic cycle.. 1.7 A look ahead.. References and suggestions for further reading.. Chapter 2: Energy, entropy, and fundamental thermodynamic concepts.. 2.1 The thermodynamic perspective.. 2.2 Thermodynamic systems and equilibrium.. 2.2.1 Fundamental thermodynamic variables.. 2.2.2 Properties of state.. 2.3 Equations of state.. 2.3.1 Ideal gas law.. 2.3.2 Equations of state for real gases.. 2.3.3 Equation of state for other substances.. 2.4 Temperature, absolute zero, and the zeroth law of thermodynamics.. 2.5 Energy and the first law of thermodynamics.. 2.5.1 Energy.. 2.5.2 Work.. 2.5.3 Path independence, exact differentials, state functions, and the first law.. 2.6 The second law and entropy.. 2.6.1 Statement.. 2.6.2 Statistical mechanics: a microscopic perspective of entropy.. 2.6.3 Integrating factors and exact differentials.. 2.7 Enthalpy.. 2.8 Heat capacity.. 2.8.1 Constant volume heat capacity.. 2.8.2 Constant pressure heat capacity.. 2.8.3 Energy associated with volume and the relationship between Cv and Cp.. 2.8.4 Heat capacity of solids: a problem in quantum physics.. 2.8.5 Relationship of entropy to other state variables.. 2.8.6 Additive nature of silicate heat capacities.. 2.9 The third law and absolute entropy.. 2.9.1 Statement of the third law.. 2.9.2 Absolute entropy.. 2.10 Calculating enthalpy and entropy changes.. 2.10.1 Enthalpy changes due to changes in temperature and pressure.. 2.10.2 Changes in enthalpy due to reactions and change of state.. 2.10.3 Entropies of reaction.. 2.11 Free energy.. 2.11.1 Helmholtz free energy.. 2.11.2 Gibbs free energy.. 2.11.3 Criteria for equilibrium and spontaneity.. 2.11.4 Temperature and pressure dependence of the Gibbs free energy.. 2.12 The Maxwell relations.. 2.13 Summary.. References and suggestions for further reading.. Problems.. Chapter 3: Solutions and thermodynamics of multicomponent systems.. 3.1 Introduction.. 3.2 Phase equilibria.. 3.2.1 Some definitions.. 3.2.2 The Gibbs phase rule.. 3.2.3 The Clapeyron equation.. 3.3 Solutions.. 3.3.1 Raoult’s law.. 3.3.2 Henry’s law.. 3.4 Chemical potential.. 3.4.1 Partial molar quantities.. 3.4.2 Definition of chemical potential and relationship to Gibbs free energy.. 3.4.3 Properties of the chemical potential.. 3.4.4 The Gibbs-Duhem relation.. 3.4.5 Derivation of the phase rule.. 3.5 Ideal solutions.. 3.5.1 Chemical potential in ideal solutions.. 3.5.2 Volume, enthalpy, entropy, and free energy changes in ideal solutions.. 3.6 Real solutions.. 3.6.1 Chemical potential in real solutions.. 3.6.2 Fugacities.. 3.6.3 Activities and activity coefficients.. 3.6.4 Excess functions.. 3.7 Electrolyte solutions.. 3.7.1 The nature of water and water–electrolyte interaction.. 3.7.2 Some definitions and conventions.. 3.7.3 Activities in electrolytes.. 3.8 Ideal solutions in crystalline solids and their activities.. 3.8.1 Mixing-on-site model.. 3.8.2 Local charge balance model.. 3.9 Equilibrium constants.. 3.9.1 Derivation and definition.. 3.9.2 Law of mass action.. 3.9.3 KD values, apparent equilibrium constants, and the solubility product.. 3.9.4 Henry’s law and gas solubilities.. 3.9.5 Temperature dependence of equilibrium constant.. 3.9.6 Pressure dependence of equilibrium constant.. 3.10 Practical approach to electrolyte equilibrium.. 3.10.1 Choosing components and species.. 3.10.2 Mass balance.. 3.10.3 Electrical neutrality.. 3.10.4 Equilibrium constant expressions.. 3.11 Oxidation and reduction.. 3.11.1 Redox in aqueous solutions.. 3.11.2 Redox in magmatic systems.. 3.12 Summary.. References and suggestions for further reading.. Problems..

Chapter 4: Applications of thermodynamics to the Earth.. 4.1 Introduction.. 4.2 Activities in nonideal solid solutions.. 4.2.1 Mathematical models of real solutions: Margules equations.. 4.3 Exsolution phenomena.. 4.4 Thermodynamics and phase diagrams.. 4.4.1 The thermodynamics of melting.. 4.4.2 Thermodynamics of phase diagrams for binary systems.. 4.4.3 Phase diagrams for multicomponent systems.. 4.5 Geothermometry and geobarometry.. 4.5.1 Theoretical considerations.. 4.5.2 Practical thermobarometers.. 4.6 Thermodynamic models of magmas.. 4.6.1 Structure of silicate melts.. 4.6.2 Magma solution models.. 4.7 Reprise: thermodynamics of electrolyte solutions.. 4.7.1 Equation of state for water.. 4.7.2 Activities and mean ionic and single ion quantities.. 4.7.3 Activities in high ionic strength solutions.. 4.7.4 Electrolyte solutions at elevated temperature and pressure.. 4.8 Summary.. References and suggestions for further reading.. Problems.. Chapter 5: Kinetics: the pace of things.. 5.1 Introduction.. 5.2 Reaction kinetics.. 5.2.1 Elementary and overall reactions.. 5.2.2 Reaction mechanisms.. 5.2.3 Reaction rates.. 5.2.4 Rates of complex reactions.. 5.2.5 Steady state and equilibrium.. 5.3 Relationships between kinetics and thermodynamics.. 5.3.1 Principle of detailed balancing.. 5.3.2 Enthalpy and activation energy.. 5.3.3 Aspects of transition state theory.. 5.4 Diffusion.. 5.4.1 Diffusion flux and Fick’s laws.. 5.4.2 Diffusion in multicomponent systems.. 5.4.3 Driving force and mechanism of diffusion.. 5.4.4 Diffusion in solids and the temperature dependence of the diffusion coefficient.. 5.4.5 Diffusion in liquids.. 5.4.6 Diffusion in porous media.. 5.5 Surfaces, interfaces, and interface processes.. 5.5.1 The surface free energy.. 5.5.2 The Kelvin effect.. 5.5.3 Nucleation and crystal growth.. 5.5.4 Adsorption.. 5.5.5 Catalysis.. 5.6 Kinetics of dissolution.. 5.6.1 Simple oxides.. 5.6.2 Silicates.. 5.6.3 Nonsilicates.. 5.7 Diagenesis.. 5.7.1 Compositional gradients in accumulating sediment.. 5.7.2 Reduction of sulfate in accumulating sediment.. 5.8 Summary.. References and suggestions for further reading.. Problems.. Chapter 6: Aquatic chemistry.. 6.1 Introduction.. 6.2 Acid–base reactions.. 6.2.1 Proton accounting, charge balance, and conservation equations.. 6.2.2 The carbonate system.. 6.2.3 Conservative and nonconservative ions.. 6.2.4 Total alkalinity and carbonate alkalinity.. 6.2.5 Buffer intensity.. 6.3 Complexation.. 6.3.1 Stability constants.. 6.3.2 Water-related complexes.. 6.3.3 Other complexes.. 6.3.4 Complexation in fresh waters.. 6.4 Dissolution and precipitation reactions.. 6.4.1 Calcium carbonate in groundwaters and surface waters.. 6.4.2 Solubility of Mg.. 6.4.3 Solubility of SiO2.. 6.4.4 Solubility of Al(OH)3 and other hydroxides.. 6.4.5 Dissolution of silicates and related minerals.. 6.5 Clays and their properties.. 6.5.1 Clay mineralogy.. 6.5.2 Ion-exchange properties of clays.. 6.6 Mineral surfaces and their interaction with solutions.. 6.6.1 Adsorption.. 6.6.2 Development of surface charge and the electric double layer.. 6.7 Summary.. References and suggestions for further reading.. Problems..

Chapter 7: Trace elements in igneous processes.. 7.1 Introduction.. 7.1.1 Why care about trace elements?.. 7.1.2 What is a trace element?.. 7.2 Behavior of the elements.. 7.2.1 Goldschmidt’s classification.. 7.2.2 The geochemical periodic table.. 7.3 Distribution of trace elements between coexisting phases.. 7.3.1 The partition coefficient.. 7.3.2 Thermodynamic basis.. 7.4 Factors governing the value of partition coefficients.. 7.4.1 Temperature and pressure dependence of the partition coefficient.. 7.4.2 Ionic size and charge.. 7.4.3 Compositional dependency.. 7.4.4 Mineral–liquid partition coefficients for mafic and ultramafic systems.. 7.5 Crystal-field effects.. 7.5.1 Crystal-field theory.. 7.5.2 Crystal-field influences on transition metal partitioning.. 7.6 Trace element distribution during partial melting.. 7.6.1 Equilibrium or batch melting.. 7.6.2 Fractional melting.. 7.6.3 Zone refining.. 7.6.4 Multiphase solids.. 7.6.5 Continuous melting.. 7.6.6 Constraints on melting models.. 7.7 Trace element distribution during crystallization.. 7.7.1 Equilibrium crystallization.. 7.7.2 Fractional crystallization.. 7.7.3 In situ crystallization.. 7.7.4 Crystallization in open system magma chambers.. 7.7.5 Comparing partial melting and crystallization.. 7.8 Summary of trace element variations during melting and crystallization.. References and suggestions for further reading.. Problems.. Chapter 8: Radiogenic isotope geochemistry.. 8.1 Introduction.. 8.2 Physics of the nucleus and the structure of nuclei.. 8.2.1 Nuclear structure and energetics.. 8.2.2 The decay of excited and unstable nuclei.. 8.3 Basics of radiogenic isotope geochemistry and geochronology.. 8.4 Decay systems and their applications.. 8.4.1 Rb-Sr.. 8.4.2 Sm-Nd.. 8.4.3 Lu-Hf.. 8.4.4 Re-Os.. 8.4.5 La-Ce.. 8.4.6 U-Th-Pb.. 8.4.7 U and Th decay series isotopes.. 8.4.8 Isotopes of He and other rare gases.. 8.5 “Extinct” and cosmogenic nuclides.. 8.5.1 “Extinct” radionuclides and their daughters.. 8.5.2 Cosmogenic nuclides.. 8.5.3 Cosmic-ray exposure ages of meteorites.. 8.6 Summary.. References and suggestions for further reading.. Problems.. Chapter 9: Stable isotope geochemistry.. 9.1 Introduction.. 9.1.1 Scope of stable isotope geochemistry.. 9.1.2 Some definitions.. 9.2 Theoretical considerations.. 9.2.1 Equilibrium isotope fractionations.. 9.2.2 Kinetic isotope fractionations.. 9.2.3 Mass-dependent and mass-independent fractionations.. 9.2.4 Isotopic clumping.. 9.3 Isotope geothermometry.. 9.4 Isotopic fractionation in the hydrologic system.. 9.5 Isotopic fractionation in biological systems.. 9.5.1 Carbon isotope fractionation during photosynthesis.. 9.5.2 Nitrogen isotope fractionation in biological processes.. 9.5.3 Oxygen and hydrogen isotope fractionation by plants.. 9.5.4 Biological fractionation of sulfur isotopes.. 9.5.5 Isotopes and diet: you are what you eat.. 9.5.6 Isotopic “fossils” and the earliest life.. 9.6 Paleoclimatology.. 9.6.1 The marine Quaternary 𝛿18O record and Milankovitch cycles.. 9.6.2 The record in glacial ice.. 9.6.3 Soils and paleosols.. 9.7 Hydrothermal systems and ore deposits.. 9.7.1 Water in hydrothermal systems.. 9.7.2 Water–rock ratios.. 9.7.3 Sulfur isotopes and ore deposits.. 9.8 Mass-independent sulfur isotope fractionation and the rise of atmospheric oxygen.. 9.9 Stable isotopes in the mantle and magmatic systems.. 9.9.1 Stable isotopic composition of the mantle.. 9.9.2 Stable isotopes in crystallizing magmas.. 9.9.3 Combined fractional crystallization and assimilation.. 9.10 Non-traditional stable isotopes.. 9.10.1 Boron isotopes.. 9.10.2 Li isotopes.. 9.10.3 Calcium isotopes.. 9.10.4 Silicon isotopes.. 9.10.5 Iron isotopes.. 9.10.6 Mercury isotopes.. 9.11 Summary.. References and suggestions for further reading.. Problems..

Chapter 10: The big picture: cosmochemistry.. 10.1 Introduction.. 10.2 In the beginning . . . nucleosynthesis.. 10.2.1 Astronomical background.. 10.2.2 The polygenetic hypothesis of Burbidge, Burbidge, Fowler, and Hoyle.. 10.2.3 Cosmological nucleosynthesis.. 10.2.4 Nucleosynthesis in stellar interiors.. 10.2.5 Explosive nucleosynthesis.. 10.2.6 Nucleosynthesis in interstellar space.. 10.2.7 Summary.. 10.3 Meteorites: essential clues to the beginning.. 10.3.1 Chondrites: the most primitive objects.. 10.3.2 Differentiated meteorites.. 10.4 Time and the isotopic composition of the solar system.. 10.4.1 Meteorite ages.. 10.4.2 Cosmic ray exposure ages and meteorite parent-bodies.. 10.4.3 Asteroids as meteorite parent-bodies.. 10.4.4 Isotopic anomalies in meteorites.. 10.5 Astronomical and theoretical constraints on solar system formation.. 10.5.1 Evolution of young stellar objects.. 10.5.2 The condensation sequence.. 10.5.3 The solar system.. 10.5.4 Other solar systems.. 10.6 Building a habitable solar system.. 10.6.1 Summary of observations.. 10.6.2 Formation of the planets.. 10.6.3 Chemistry and history of the moon.. 10.6.4 The giant impact hypothesis and formation of the earth and the moon.. 10.6.5 Tungsten isotopes and the age of the Earth.. 10.7 Summary.. References and suggestions for further reading.. Problems.. Chapter 11: Geochemistry of the solid Earth.. 11.1 Introduction.. 11.2 The Earth’s mantle.. 11.2.1 Structure of the mantle and geophysical constraints on mantle composition.. 11.2.2 Cosmochemical constraints on mantle composition.. 11.2.3 Observational constraints on mantle composition.. 11.2.4 Mantle mineralogy and phase transitions.. 11.3 Estimating mantle and bulk Earth composition.. 11.3.1 Major element composition.. 11.3.2 Trace element composition.. 11.3.3 Composition of the bulk silicate earth.. 11.4 The Earth’s core and its composition.. 11.4.1 Geophysical constraints.. 11.4.2 Cosmochemical constraints.. 11.4.3 Experimental constraints.. 11.5 Mantle geochemical reservoirs.. 11.5.1 Evidence from oceanic basalts.. 11.5.2 Evolution of the depleted MORB mantle.. 11.5.3 Evolution of mantle plume reservoirs.. 11.5.4 The subcontinental lithospheric mantle.. 11.6 The crust.. 11.6.1 The oceanic crust.. 11.6.2 The continental crust.. 11.6.3 Growth of the continental crust.. 11.6.4 Refining the continental crust.. 11.7 Subduction zone processes.. 11.7.1 Major element composition.. 11.7.2 Trace element composition.. 11.7.3 Isotopic composition and sediment subduction.. 11.7.4 Magma genesis in subduction zones.. 11.8 Summary.. References and suggestions for further reading.. Problems..

Chapter 12: Organic geochemistry, the carbon cycle, and climate.. 12.1 Introduction.. 12.2 A brief biological background.. 12.3 Organic compounds and their nomenclature.. 12.3.1 Hydrocarbons.. 12.3.2 Functional groups.. 12.3.3 Short-hand notations of organic molecules.. 12.3.4 Biologically important organic compounds.. 12.4 The chemistry of life: important biochemical processes.. 12.4.1 Photosynthesis.. 12.4.2 Respiration.. 12.4.3 The stoichiometry of life.. 12.5 Organic matter in natural waters and soils.. 12.5.1 Organic matter in soils.. 12.5.2 Dissolved organic matter in aquatic and marine environments.. 12.5.3 Hydrocarbons in natural waters.. 12.6 Chemical properties of organic molecules.. 12.6.1 Acid–base properties.. 12.6.2 Complexation.. 12.6.3 Adsorption phenomena.. 12.7 Sedimentary organic matter.. 12.7.1 Preservation of organic matter.. 12.7.2 Diagenesis of marine sediments.. 12.7.3 Diagenesis of aquatic sediments.. 12.7.4 Summary of diagenetic changes.. 12.7.5 Biomarkers.. 12.7.6 Kerogen and bitumen.. 12.7.7 Isotope composition of sedimentary organic matter.. 12.8 Petroleum and coal formation.. 12.8.1 Petroleum.. 12.8.2 Compositional evolution of coal.. 12.9 The carbon cycle and climate.. 12.9.1 Greenhouse energy balance.. 12.9.2 The exogenous carbon cycle.. 12.9.3 The deep carbon cycle.. 12.9.4 Evolutionary changes affecting the carbon cycle.. 12.9.5 The carbon cycle and climate through time.. 12.9.6 Fossil fuels and anthropogenic climate change.. 12.10 Summary.. References and suggestions for further reading.. Problems.. Chapter 13: The land surface: weathering, soils, and streams.. 13.1 Introduction.. 13.2 Redox in natural waters.. 13.2.1 Biogeochemical redox reactions.. 13.2.2 Eutrophication.. 13.2.3 Redox buffers and transition metal chemistry.. 13.3 Weathering, soils, and biogeochemical cycling.. 13.3.1 Soil profiles.. 13.3.2 Chemical cycling in soils.. 13.3.3 Biogeochemical cycling.. 13.4 Weathering rates.. 13.4.1 The in situ approach.. 13.4.2 The watershed approach.. 13.4.3 Factors controlling weathering rates.. 13.5 The composition of rivers.. 13.6 Continental saline waters.. 13.7 Summary.. References and suggestions for further reading.. Problems.. Chapter 14: The ocean as a chemical system.. 14.1 Introduction.. 14.2 Some background oceanographic concepts.. 14.2.1 Salinity, chlorinity, temperature, and density.. 14.2.2 Circulation of the ocean and the structure of ocean water.. 14.3 Composition of seawater.. 14.3.1 Speciation in seawater.. 14.3.2 Conservative elements.. 14.3.3 Dissolved gases.. 14.3.4 Seawater pH and alkalinity.. 14.3.5 Carbonate dissolution and precipitation.. 14.3.6 Nutrient elements.. 14.3.7 Particle-reactive elements.. 14.3.8 One-dimensional advection–diffusion model.. 14.4 Sources and sinks of dissolved matter in seawater.. 14.4.1 Residence time.. 14.4.2 River and groundwater flux to the oceans.. 14.4.3 The hydrothermal flux.. 14.4.4 The atmospheric source.. 14.4.5 Sedimentary sinks and sources.. 14.5 Summary.. References.. Problems.. Chapter 15: Applied geochemistry.. 15.1 Introduction.. 15.2 Mineral resources.. 15.2.1 Ore deposits: definitions and classification.. 15.2.2 Orthomagmatic ore deposits.. 15.2.3 Hydromagmatic ore deposits.. 15.2.4 Hydrothermal ore deposits.. 15.2.5 Sedimentary ore deposits.. 15.2.6 Weathering-related ore deposits.. 15.2.7 Rare earth ore deposits.. 15.2.8 Geochemical exploration: finding future resources.. 15.3 Environmental geochemistry.. 15.3.1 Eutrophication redux.. 15.3.2 Toxic metals in the environment.. 15.3.3 Acid deposition.. 15.4 Summary.. References.. Problems.. Appendix: constants, units and conversions.. Index

A Comprehensive Introduction to the “Geochemist Toolbox” – the Basic Principles of Modern Geochemistry. In the new edition of William M. White’s Geochemistry, undergraduate and graduate students will find each of the core principles of geochemistry covered. From defining key principles and methods to examining Earth’s core composition and exploring organic chemistry and fossil fuels, this definitive edition encompasses all the information needed for a solid foundation in the earth sciences for beginners and beyond. For researchers and applied scientists, this book will act as a useful reference on fundamental theories of geochemistry, applications, and environmental sciences. The new edition includes new chapters on the geochemistry of the Earth’s surface (the “critical zone”), marine geochemistry, and applied geochemistry as it relates to environmental applications and geochemical exploration. ● A review of the fundamentals of geochemical thermodynamics and kinetics, trace element and organic geochemistry. ● An introduction to radiogenic and stable isotope geochemistry and applications such as geologic time, ancient climates, and diets of prehistoric people. ● Formation of the Earth and composition and origins of the core, the mantle, and the crust. ● New chapters that cover soils and streams, the oceans, and geochemistry applied to the environment and mineral exploration. In this foundational look at geochemistry, new learners and professionals will find the answer to the essential principles and techniques of the science behind the Earth and its environs. eng