Isotope Geochemistry
Published on 30. January 2015
Book
Paperback/Softback
496 pages
978-0-470-65670-9 (ISBN)
Description
This book provides a comprehensive introduction to radiogenic andstable isotope geochemistry. Beginning with a brief overview ofnuclear physics and nuclear origins, it then reviews radioactivedecay schemes and their use in geochronology. A following chaptercovers the closely related techniques such as fission-track andcarbon-14 dating. Subsequent chapters cover nucleosyntheticanomalies in meteorites and early solar system chronology and theuse of radiogenic isotopes in understanding the evolution of theEarth's mantle, crust, and oceans. Attention then turns tostable isotopes and after reviewing the basic principles involved,the book explores their use in topics as diverse as mantleevolution, archeology and paleontology, ore formation, and,particularly, paleoclimatology. A following chapter explores recentdevelopments including unconventional stable isotopes,mass-independent fractionation, and isotopic'clumping'. The final chapter reviews the isotopicvariation in the noble gases, which result from both radioactivedecay and chemical fractionations.
More details
Series
Edition
1. Auflage
Language
English
Place of publication
Hoboken
United Kingdom
Publishing group
John Wiley and Sons Ltd
Target group
Professional and scholarly
Dimensions
Height: 27.9 cm
Width: 21.6 cm
Thickness: 1.5 cm
Weight
666 gr
ISBN-13
978-0-470-65670-9 (9780470656709)
Schweitzer Classification
Other editions
New editions
Additional editions
Person
William White teaches geochemistry as a Professor of earth and atmospheric sciences at Cornell University. He received a B.A. in geology from the University of California, Berkeley and a PhD in oceanography from the University of Rhode Island. He is a Fellow of the Geochemical Society/European Association of Geochemistry and the AGU and has been named a highly cited author by ISI. He is the author of Geochemistry, also published by Wiley-Blackwell.
Content
Preface xi
About the companion website xiii
Chapter 1: Atoms and nuclei: their physics and origins 1
1.1 Introduction 1
1.2 Physics of the Nucleus 2
1.2.1 Early development of atomic and the nuclear theory 2
1.2.2 Some definitions and units 3
1.2.3 Nucleons, nuclei, and nuclear forces 3
1.2.4 Atomic masses and binding energies 4
1.2.5 The liquid-drop model 6
1.2.6 The shell model of the nucleus 7
1.2.7 Collective model 11
1.3 Radioactive Decay 12
1.3.1 Gamma decay 12
1.3.2 Alpha decay 13
1.3.3 Beta decay 13
1.3.4 Electron capture 14
1.3.5 Spontaneous fission 15
1.4 Nucleosynthesis 16
1.4.1 Cosmological nucleosynthesis 18
1.4.2 Stellar nucleosynthesis 18
1.4.3 Explosive nucleosynthesis 25
1.4.4 Nucleosynthesis in interstellar space 27
1.4.5 Summary 28
Notes 29
References 29
Suggestions for Further Reading 30
Problems 30
Chapter 2: Decay systems and geochronology I 32
2.1 Basics of Radioactive Isotope Geochemistry 32
2.1.1 Introduction 32
2.1.2 The basic equations 33
2.1.3 A special case: the U-Th-Pb system 35
2.2 Geochronology 36
2.2.1 Isochron dating 36
2.2.2 Calculating an isochron 37
2.3 The K-Ar-Ca System 39
2.3.1 Diffusion, cooling rates, and closure temperatures 40
2.3.2 40Ar-39Ar dating 43
2.4 The Rb-Sr System 47
2.4.1 Rb-Sr chemistry and geochronology 48
2.4.2 Sr isotope chronostratigraphy 49
2.5 The Sm-Nd System 50
2.5.1 Sm-Nd model ages and crustal residence times 55
2.6 The Lu-Hf System 56
2.7 The Re-Os System 61
2.7.1 The Re-Os decay system 61
2.7.2 Re-Os geochronology 63
2.7.3 The 190Pt-186Os decay 65
Notes 66
References 66
Suggestions for Further Reading 68
Problems 69
Chapter 3: Decay systems and geochronology II: U and Th 72
3.1 Introduction 72
3.1.1 Chemistry of U, Th, and Pb 72
3.1.2 The 238U/235U ratio and uranium decay constants 73
3.2 Pb-Pb Ages and Isochrons 74
3.2.1 Total U-Pb isochrons 76
3.2.2 Th/U ratios 77
3.3 Zircon Dating 77
3.4 U-decay Series Dating 83
3.4.1 Basic principles 84
3.4.2 234U-238U dating 86
3.4.3 230Th-238U dating 88
3.4.4 231Pa-235U dating 91
3.4.5 226Ra dating 93
3.4.6 210Pb dating 93
3.4.7 210Po-210Pb dating 95
Notes 96
References 97
Suggestions for Further Reading 98
Problems 98
Chapter 4: Geochronology III: other dating methods 101
4.1 Cosmogenic Nuclides 101
4.1.1 Cosmic rays in the atmosphere 101
4.1.2 14C dating 102
4.1.3 10Be, 26Al, and 36Cl 106
4.1.4 Cosmogenic and bomb-produced radionuclides in hydrology 108
4.1.5 In-situ produced cosmogenic nuclides 110
4.2 Fission Tracks 114
4.2.1 Analytical procedures 115
4.2.2 Interpreting fission track ages 117
4.2.3 Interpreting track length 119
Notes 121
References 122
Suggestions for Further Reading 123
Problems 123
Chapter 5: Isotope cosmochemistry 125
5.1 Introduction 125
5.2 Cosmochronology 126
5.2.1 Conventional methods 126
5.2.2 Extinct radionuclides 129
5.2.3 Extinct radionuclides in the Earth 136
5.2.4 Origin of short-lived nuclides 145
5.3 Stardust and Isotopic Anomalies in Meteorites 146
5.3.1 Neon alphabet soup and "pre-solar" noble gases in meteorites 146
5.3.2 Isotopic composition of pre-solar grains 148
5.3.3 Other exotic components in meteorites 151
5.4 Oxygen Isotope Variations and Nebular Processes 151
5.5 Exposure Ages of Meteorites 154
Notes 154
References 155
Suggestions for Further Reading 158
Problems 159
Chapter 6: Radiogenic isotope geochemistry of the mantle 161
6.1 Introduction 161
6.1.1 Definitions: time-integrated and time-averaged 162
6.2 Isotope Geochemistry of the Earth's Mantle 163
6.2.1 The Sr-Nd-Hf picture 163
6.2.2 The Pb picture 166
6.3 Balancing Depleted Mantle and Crust 172
6.4 Mantle Plume Reservoirs 179
6.4.1 Mantle plumes and the mantle zoo 179
6.4.2 The evolution of mantle geochemical reservoirs 180
6.5 Geographic Variations in Mantle Isotopic Composition 187
6.6 The Subcontinental Lithosphere 189
6.7 U-Series Isotopes and Melt Generation 193
6.7.1 Spiegelman and Elliot model of melt transport 194
Notes 198
References 201
Suggestions for Further Reading 203
Problems 204
Chapter 7: Radiogenic isotope geochemistry of the continental crust and the oceans 205
7.1 Introduction 205
7.2 Growth of the Continental Crust Through Time 205
7.2.1 Mechanisms of crustal growth 205
7.2.2 The Hadean eon and the earliest continental crust 206
7.2.3 Subsequent growth of the crust 212
7.2.4 Nd and Hf isotopic approaches to crustal evolution 215
7.3 Isotopic Composition of the Continental Crust 217
7.3.1 Sediments and rivers as samples of the upper crust 218
7.3.2 Isotopic composition of the lower crust 221
7.3.3 Pb isotope ratios and the Th/U ratio of the crust 223
7.4 Other Approaches to Crustal Composition and Evolution 224
7.5 Subduction Zones 226
7.5.1 Geochemistry of two-component mixtures 226
7.5.2 Isotopic compositions of subduction-related magmas 228
7.6 Radiogenic Isotopes in Oceanography 231
7.6.1 Oceanographic circulation and geochemical cycling 232
7.6.2 Nd, Hf, Os, and Pb in the modern ocean 233
7.6.3 Radiogenic isotopes in paleoceanography 236
Notes 240
References 240
Suggestions for Further Reading 244
Problems 244
Chapter 8: Stable isotope geochemistry I: Theory 246
8.1 Introduction 246
8.2 Notation and Definitions 246
8.2.1 The ?? notation 246
8.2.2 The fractionation factor 247
8.3 Theory of Mass Dependent Isotopic Fractionations 247
8.3.1 Equilibrium fractionations 249
8.3.2 Kinetic fractionation 258
8.4 Mass Independent Fractionation 260
8.5 Hydrogen and Oxygen Isotope Ratios in the Hydrologic System 262
8.6 Isotope Fractionation in the Biosphere 265
8.6.1 Carbon isotope fractionation during photosynthesis 265
8.6.2 Nitrogen isotope fractionation in biological processes 269
8.6.3 Oxygen and hydrogen isotope fractionation by plants 271
8.6.4 Carbon and hydrogen isotopic composition of organic matter in sediments 271
8.6.5 Biological fractionation of sulfur isotopes 273
Notes 274
References 274
Suggestions for Further Reading 275
Problems 276
Chapter 9: Stable isotope geochemistry II: High temperature applications 277
9.1 Introduction 277
9.2 Equilibrium Fractionations Among Minerals 277
9.2.1 Compositional and structural dependence of equilibrium fractionations 277
9.2.2 Geothermometry 279
9.3 Stable Isotope Composition of the Mantle 282
9.3.1 Oxygen 283
9.3.2 Carbon 284
9.3.3 Hydrogen 286
9.3.4 Nitrogen 287
9.3.5 Sulfur 288
9.4 Oxygen Isotopes in Magmatic Processes 288
9.4.1 Oxygen isotope changes during crystallization 289
9.4.2 Combined fractional crystallization and assimilation 291
9.4.3 Combining radiogenic and oxygen isotopes 291
9.4.4 Sediment subduction versus assimilation 292
9.4.5 Stable isotopes as indicators of crust-to-mantle recycling 296
9.5 Oxygen Isotopes in Hydrothermal Systems 298
9.5.1 Ridge crest hydrothermal activity and metamorphism of the oceanic crust 298
9.5.2 Meteoric geothermal systems 301
9.5.3 Water-rock reaction: Theory 301
9.5.4 The Skaergaard intrusion 303
9.5.5 Oxygen isotopes and mineral exploration 304
9.6 Sulfur Isotopes and Ores 305
9.6.1 Introduction 305
9.6.2 Sulfur isotope fractionations in magmatic processes 306
9.6.3 Sulfur isotope fractionation in hydrothermal systems 307
9.6.4 Isotopic composition of sulfide ores 309
Notes 312
References 312
Suggestions for Further Reading 314
Problems 315
Chapter 10: Stable isotope geochemistry III: Low temperature applications 316
10.1 Stable Isotopes in Paleontology, Archeology, and the Environment 316
10.1.1 Introduction 316
10.1.2 Isotopes and diet: You are what you eat 316
10.1.3 Carbon isotopes and the evolution of horses and grasslands 318
10.1.4 Isotopes, archeology, and paleodiets 321
10.1.5 Carbon isotopes and the earliest life 323
10.1.6 Tracing methane contamination in drinking water 325
10.2 Stable Isotopes in Paleoclimatology 326
10.2.1 Introduction 326
10.2.2 The record of climate change in deep sea sediments 327
10.2.3 The quaternary ?18O record 327
10.2.4 The cause of quaternary glaciations 329
10.2.5 Carbon isotopes, ocean circulation, and climate 332
10.2.6 The tertiary marine ?18O record 334
10.2.7 Continental isotopic records 336
10.2.8 Vostok and EPICA Antarctic ice cores 337
10.2.9 Ice records from Greenland: GRIP, GISP, and NGRIP 338
10.2.10Speleotherm and related climate records 340
10.2.11Soils and paleosols 341
10.3 The Carbon Cycle, Isotopes, and Climate 342
10.3.1 The short-term carbon cycle and anthropogenic impacts 342
10.3.2 The quaternary carbon isotope record and glacial cycles 347
10.3.3 The long-term carbon cycle 351
Notes 359
References 359
Suggestions for Further Reading 362
Problems 363
Chapter 11: Unconventional isotopes and approaches 364
11.1 Introduction 364
11.2 Applications of Isotopic Clumping 365
11.3 Mass Independent Isotope Fractionations 368
11.3.1 Mass-independent fractionation of oxygen in the atmosphere 368
11.3.2 Mass independent sulfur isotope fractionation and the rise of atmospheric oxygen 369
11.4 Isotopes of Iron and Molybdenum 370
11.4.1 Fe isotopes and the great oxidation event 371
11.4.2 Mo isotopes and oxygenation of the oceans 374
11.5 Isotopes of Copper and Zinc 377
11.5.1 Cu isotopes 377
11.5.2 Zn isotopes 380
11.6 Isotopes of Boron and Lithium 383
11.6.1 Boron isotopes 384
11.6.2 Li isotopes 389
11.7 Isotopes of Magnesium and Calcium 392
11.7.1 Mg isotopes 392
11.7.2 Calcium isotopes 396
11.8 Silicon Isotopes 400
11.9 Chlorine Isotopes 404
Notes 407
References 408
Suggestions for Further Reading 416
Problems 416
Chapter 12: Noble gas isotope geochemistry 418
12.1 Introduction 418
12.1.1 Noble gas chemistry 418
12.1.2 Noble gases in the Solar System 419
12.2 Helium 422
12.2.1 He in the atmosphere, crust, and oceans 422
12.2.2 He in the mantle 424
12.3 Neon 426
12.3.1 Neon in the solid earth 428
12.4 Argon 429
12.5 Krypton 431
12.6 Xenon 432
12.7 Implications of Noble Gas Isotope Ratios for the Origin and Evolution of the Earth 436
12.7.1 Mantle reservoirs of noble gases in the modern Earth 436
12.7.2 Formation of the Earth and evolution of the atmosphere 443
Notes 447
References 448
Suggestions for Further Reading 452
Problems 452
Appendix: Mass spectrometry 453
A.1 Sample Extraction and Preparation 453
A.2 The Mass Spectrometer 453
A.2.1 The ion source 454
A.2.2 The mass analyzer 455
A.2.3 The detector 457
A.3 Accelerator Mass Spectrometry 458
A.4 Analytical Strategies 459
A.4.1 Correcting mass fractionation 459
A.4.2 Deconvolution of results 461
A.4.3 Isotope dilution analysis 461
Notes 462
References 463
Problems 463
Index 465
About the companion website xiii
Chapter 1: Atoms and nuclei: their physics and origins 1
1.1 Introduction 1
1.2 Physics of the Nucleus 2
1.2.1 Early development of atomic and the nuclear theory 2
1.2.2 Some definitions and units 3
1.2.3 Nucleons, nuclei, and nuclear forces 3
1.2.4 Atomic masses and binding energies 4
1.2.5 The liquid-drop model 6
1.2.6 The shell model of the nucleus 7
1.2.7 Collective model 11
1.3 Radioactive Decay 12
1.3.1 Gamma decay 12
1.3.2 Alpha decay 13
1.3.3 Beta decay 13
1.3.4 Electron capture 14
1.3.5 Spontaneous fission 15
1.4 Nucleosynthesis 16
1.4.1 Cosmological nucleosynthesis 18
1.4.2 Stellar nucleosynthesis 18
1.4.3 Explosive nucleosynthesis 25
1.4.4 Nucleosynthesis in interstellar space 27
1.4.5 Summary 28
Notes 29
References 29
Suggestions for Further Reading 30
Problems 30
Chapter 2: Decay systems and geochronology I 32
2.1 Basics of Radioactive Isotope Geochemistry 32
2.1.1 Introduction 32
2.1.2 The basic equations 33
2.1.3 A special case: the U-Th-Pb system 35
2.2 Geochronology 36
2.2.1 Isochron dating 36
2.2.2 Calculating an isochron 37
2.3 The K-Ar-Ca System 39
2.3.1 Diffusion, cooling rates, and closure temperatures 40
2.3.2 40Ar-39Ar dating 43
2.4 The Rb-Sr System 47
2.4.1 Rb-Sr chemistry and geochronology 48
2.4.2 Sr isotope chronostratigraphy 49
2.5 The Sm-Nd System 50
2.5.1 Sm-Nd model ages and crustal residence times 55
2.6 The Lu-Hf System 56
2.7 The Re-Os System 61
2.7.1 The Re-Os decay system 61
2.7.2 Re-Os geochronology 63
2.7.3 The 190Pt-186Os decay 65
Notes 66
References 66
Suggestions for Further Reading 68
Problems 69
Chapter 3: Decay systems and geochronology II: U and Th 72
3.1 Introduction 72
3.1.1 Chemistry of U, Th, and Pb 72
3.1.2 The 238U/235U ratio and uranium decay constants 73
3.2 Pb-Pb Ages and Isochrons 74
3.2.1 Total U-Pb isochrons 76
3.2.2 Th/U ratios 77
3.3 Zircon Dating 77
3.4 U-decay Series Dating 83
3.4.1 Basic principles 84
3.4.2 234U-238U dating 86
3.4.3 230Th-238U dating 88
3.4.4 231Pa-235U dating 91
3.4.5 226Ra dating 93
3.4.6 210Pb dating 93
3.4.7 210Po-210Pb dating 95
Notes 96
References 97
Suggestions for Further Reading 98
Problems 98
Chapter 4: Geochronology III: other dating methods 101
4.1 Cosmogenic Nuclides 101
4.1.1 Cosmic rays in the atmosphere 101
4.1.2 14C dating 102
4.1.3 10Be, 26Al, and 36Cl 106
4.1.4 Cosmogenic and bomb-produced radionuclides in hydrology 108
4.1.5 In-situ produced cosmogenic nuclides 110
4.2 Fission Tracks 114
4.2.1 Analytical procedures 115
4.2.2 Interpreting fission track ages 117
4.2.3 Interpreting track length 119
Notes 121
References 122
Suggestions for Further Reading 123
Problems 123
Chapter 5: Isotope cosmochemistry 125
5.1 Introduction 125
5.2 Cosmochronology 126
5.2.1 Conventional methods 126
5.2.2 Extinct radionuclides 129
5.2.3 Extinct radionuclides in the Earth 136
5.2.4 Origin of short-lived nuclides 145
5.3 Stardust and Isotopic Anomalies in Meteorites 146
5.3.1 Neon alphabet soup and "pre-solar" noble gases in meteorites 146
5.3.2 Isotopic composition of pre-solar grains 148
5.3.3 Other exotic components in meteorites 151
5.4 Oxygen Isotope Variations and Nebular Processes 151
5.5 Exposure Ages of Meteorites 154
Notes 154
References 155
Suggestions for Further Reading 158
Problems 159
Chapter 6: Radiogenic isotope geochemistry of the mantle 161
6.1 Introduction 161
6.1.1 Definitions: time-integrated and time-averaged 162
6.2 Isotope Geochemistry of the Earth's Mantle 163
6.2.1 The Sr-Nd-Hf picture 163
6.2.2 The Pb picture 166
6.3 Balancing Depleted Mantle and Crust 172
6.4 Mantle Plume Reservoirs 179
6.4.1 Mantle plumes and the mantle zoo 179
6.4.2 The evolution of mantle geochemical reservoirs 180
6.5 Geographic Variations in Mantle Isotopic Composition 187
6.6 The Subcontinental Lithosphere 189
6.7 U-Series Isotopes and Melt Generation 193
6.7.1 Spiegelman and Elliot model of melt transport 194
Notes 198
References 201
Suggestions for Further Reading 203
Problems 204
Chapter 7: Radiogenic isotope geochemistry of the continental crust and the oceans 205
7.1 Introduction 205
7.2 Growth of the Continental Crust Through Time 205
7.2.1 Mechanisms of crustal growth 205
7.2.2 The Hadean eon and the earliest continental crust 206
7.2.3 Subsequent growth of the crust 212
7.2.4 Nd and Hf isotopic approaches to crustal evolution 215
7.3 Isotopic Composition of the Continental Crust 217
7.3.1 Sediments and rivers as samples of the upper crust 218
7.3.2 Isotopic composition of the lower crust 221
7.3.3 Pb isotope ratios and the Th/U ratio of the crust 223
7.4 Other Approaches to Crustal Composition and Evolution 224
7.5 Subduction Zones 226
7.5.1 Geochemistry of two-component mixtures 226
7.5.2 Isotopic compositions of subduction-related magmas 228
7.6 Radiogenic Isotopes in Oceanography 231
7.6.1 Oceanographic circulation and geochemical cycling 232
7.6.2 Nd, Hf, Os, and Pb in the modern ocean 233
7.6.3 Radiogenic isotopes in paleoceanography 236
Notes 240
References 240
Suggestions for Further Reading 244
Problems 244
Chapter 8: Stable isotope geochemistry I: Theory 246
8.1 Introduction 246
8.2 Notation and Definitions 246
8.2.1 The ?? notation 246
8.2.2 The fractionation factor 247
8.3 Theory of Mass Dependent Isotopic Fractionations 247
8.3.1 Equilibrium fractionations 249
8.3.2 Kinetic fractionation 258
8.4 Mass Independent Fractionation 260
8.5 Hydrogen and Oxygen Isotope Ratios in the Hydrologic System 262
8.6 Isotope Fractionation in the Biosphere 265
8.6.1 Carbon isotope fractionation during photosynthesis 265
8.6.2 Nitrogen isotope fractionation in biological processes 269
8.6.3 Oxygen and hydrogen isotope fractionation by plants 271
8.6.4 Carbon and hydrogen isotopic composition of organic matter in sediments 271
8.6.5 Biological fractionation of sulfur isotopes 273
Notes 274
References 274
Suggestions for Further Reading 275
Problems 276
Chapter 9: Stable isotope geochemistry II: High temperature applications 277
9.1 Introduction 277
9.2 Equilibrium Fractionations Among Minerals 277
9.2.1 Compositional and structural dependence of equilibrium fractionations 277
9.2.2 Geothermometry 279
9.3 Stable Isotope Composition of the Mantle 282
9.3.1 Oxygen 283
9.3.2 Carbon 284
9.3.3 Hydrogen 286
9.3.4 Nitrogen 287
9.3.5 Sulfur 288
9.4 Oxygen Isotopes in Magmatic Processes 288
9.4.1 Oxygen isotope changes during crystallization 289
9.4.2 Combined fractional crystallization and assimilation 291
9.4.3 Combining radiogenic and oxygen isotopes 291
9.4.4 Sediment subduction versus assimilation 292
9.4.5 Stable isotopes as indicators of crust-to-mantle recycling 296
9.5 Oxygen Isotopes in Hydrothermal Systems 298
9.5.1 Ridge crest hydrothermal activity and metamorphism of the oceanic crust 298
9.5.2 Meteoric geothermal systems 301
9.5.3 Water-rock reaction: Theory 301
9.5.4 The Skaergaard intrusion 303
9.5.5 Oxygen isotopes and mineral exploration 304
9.6 Sulfur Isotopes and Ores 305
9.6.1 Introduction 305
9.6.2 Sulfur isotope fractionations in magmatic processes 306
9.6.3 Sulfur isotope fractionation in hydrothermal systems 307
9.6.4 Isotopic composition of sulfide ores 309
Notes 312
References 312
Suggestions for Further Reading 314
Problems 315
Chapter 10: Stable isotope geochemistry III: Low temperature applications 316
10.1 Stable Isotopes in Paleontology, Archeology, and the Environment 316
10.1.1 Introduction 316
10.1.2 Isotopes and diet: You are what you eat 316
10.1.3 Carbon isotopes and the evolution of horses and grasslands 318
10.1.4 Isotopes, archeology, and paleodiets 321
10.1.5 Carbon isotopes and the earliest life 323
10.1.6 Tracing methane contamination in drinking water 325
10.2 Stable Isotopes in Paleoclimatology 326
10.2.1 Introduction 326
10.2.2 The record of climate change in deep sea sediments 327
10.2.3 The quaternary ?18O record 327
10.2.4 The cause of quaternary glaciations 329
10.2.5 Carbon isotopes, ocean circulation, and climate 332
10.2.6 The tertiary marine ?18O record 334
10.2.7 Continental isotopic records 336
10.2.8 Vostok and EPICA Antarctic ice cores 337
10.2.9 Ice records from Greenland: GRIP, GISP, and NGRIP 338
10.2.10Speleotherm and related climate records 340
10.2.11Soils and paleosols 341
10.3 The Carbon Cycle, Isotopes, and Climate 342
10.3.1 The short-term carbon cycle and anthropogenic impacts 342
10.3.2 The quaternary carbon isotope record and glacial cycles 347
10.3.3 The long-term carbon cycle 351
Notes 359
References 359
Suggestions for Further Reading 362
Problems 363
Chapter 11: Unconventional isotopes and approaches 364
11.1 Introduction 364
11.2 Applications of Isotopic Clumping 365
11.3 Mass Independent Isotope Fractionations 368
11.3.1 Mass-independent fractionation of oxygen in the atmosphere 368
11.3.2 Mass independent sulfur isotope fractionation and the rise of atmospheric oxygen 369
11.4 Isotopes of Iron and Molybdenum 370
11.4.1 Fe isotopes and the great oxidation event 371
11.4.2 Mo isotopes and oxygenation of the oceans 374
11.5 Isotopes of Copper and Zinc 377
11.5.1 Cu isotopes 377
11.5.2 Zn isotopes 380
11.6 Isotopes of Boron and Lithium 383
11.6.1 Boron isotopes 384
11.6.2 Li isotopes 389
11.7 Isotopes of Magnesium and Calcium 392
11.7.1 Mg isotopes 392
11.7.2 Calcium isotopes 396
11.8 Silicon Isotopes 400
11.9 Chlorine Isotopes 404
Notes 407
References 408
Suggestions for Further Reading 416
Problems 416
Chapter 12: Noble gas isotope geochemistry 418
12.1 Introduction 418
12.1.1 Noble gas chemistry 418
12.1.2 Noble gases in the Solar System 419
12.2 Helium 422
12.2.1 He in the atmosphere, crust, and oceans 422
12.2.2 He in the mantle 424
12.3 Neon 426
12.3.1 Neon in the solid earth 428
12.4 Argon 429
12.5 Krypton 431
12.6 Xenon 432
12.7 Implications of Noble Gas Isotope Ratios for the Origin and Evolution of the Earth 436
12.7.1 Mantle reservoirs of noble gases in the modern Earth 436
12.7.2 Formation of the Earth and evolution of the atmosphere 443
Notes 447
References 448
Suggestions for Further Reading 452
Problems 452
Appendix: Mass spectrometry 453
A.1 Sample Extraction and Preparation 453
A.2 The Mass Spectrometer 453
A.2.1 The ion source 454
A.2.2 The mass analyzer 455
A.2.3 The detector 457
A.3 Accelerator Mass Spectrometry 458
A.4 Analytical Strategies 459
A.4.1 Correcting mass fractionation 459
A.4.2 Deconvolution of results 461
A.4.3 Isotope dilution analysis 461
Notes 462
References 463
Problems 463
Index 465