Radiogenic isotope geology / Alan P. Dickin.

Format:

Book

Author/Creator:

Dickin, Alan P.

Language:

English

Subjects (All):

Isotope geology.

Radioactive dating.

Physical Description:

xvi, 492 pages : illustrations ; 26 cm

Edition:

Second edition.

Place of Publication:

Cambridge ; New York : Cambridge University Press, 2005.

Summary:

Modern isotope geochemistry is a rapidly expanding field that has a part to play in a broad range of earth and planetary sciences - from extra-solar system processes to environmental geoscience. This new edition of a popular textbook is completely updated and places more emphasis on the uses of radiogenic isotopes in environmental earth science.

The author reviews the field of radiogenic isotope geology in a concise and visual manner to provide a comprehensive introduction to the subject and its wide variety of applications. For each technique, current ideas are presented in their historical context to allow the reader to understand the development of the field. The latest ideas and methods, classic papers and case studies all come under scrutiny within this book, with the text gathered around classic diagrams from the literature. This is an important reference for students and researchers working in isotope geology and an accessible introduction for scientists from other disciplines.

Contents:

1 Nucleosynthesis and nuclear decay 1

1.1 The chart of the nuclides 1

1.2 Nucleosynthesis 2

1.2.1 Stellar evolution 3

1.2.2 Stages in the nucleosynthesis of heavy elements 4

1.3 Radioactive decay 7

1.3.1 Isobaric decay 7

1.3.2 Alpha- and heavy-particle decay 9

1.3.3 Nuclear fission and the Oklo natural reactor 10

1.4 The law of radioactive decay 11

1.4.1 Uniformitarianism 12

2 Mass spectrometry 15

2.1 Chemical separation 16

2.1.1 Rb-Sr 16

2.1.2 Sm-Nd 17

2.1.3 Lu-Hf 17

2.1.4 Lead 17

2.2 Ion sources 18

2.2.1 Thermal ionisation 19

2.2.2 Plasma-source mass spectrometry 20

2.2.3 Mass fractionation 21

2.3 Magnetic-sector mass spectrometry 24

2.3.1 Ion optics 25

2.3.2 Detectors 27

2.3.3 Data collection 28

2.4 Isotope dilution 29

2.4.1 Analysis technique 30

2.4.2 Double spiking 31

2.5 Applications of MC-ICP-MS to radiogenic isotopes 32

2.5.1 Hf-W 33

2.5.2 Lu-Hf 33

2.5.3 U-Th 33

2.5.4 Pb-Pb 33

2.5.5 U-Pb 33

2.5.6 Sm-Nd 34

2.6 Isochron regression-line fitting 34

2.6.1 Types of regression fit 35

2.6.2 Regression fitting with correlated errors 36

2.6.3 Errorchrons 36

2.6.4 Dealing with errorchrons 36

3 The Rb-Sr method 42

3.1 The Rb decay constant 42

3.2 Dating igneous rocks 43

3.2.1 Sr model ages 43

3.2.2 The isochron diagram 43

3.2.3 Erupted isochrons 45

3.2.4 Meteorite chronology 47

3.3 Dating metamorphic rocks 48

3.3.1 Open mineral systems 48

3.3.2 Blocking temperatures 49

3.3.3 Open whole-rock systems 51

3.4 Dating ore deposits 52

3.5 Dating sedimentary rocks 54

3.5.1 Shales 55

3.5.2 Glauconite 56

3.6 Seawater evolution 57

3.6.1 Measurement of the curve 57

3.6.2 Modelling the fluxes 62

3.6.3 The effects of Himalayan erosion 63

4 The Sm-Nd method 70

4.1 Sm-Nd isochrons 70

4.1.1 Meteorites 70

4.1.2 Low-grade meta-igneous rocks 71

4.1.3 High-grade metamorphic rocks 73

4.1.4 High-grade metamorphic minerals 75

4.2 Nd isotope evolution and model ages 76

4.2.1 Chondritic model ages 77

4.2.2 Depleted-mantle model ages 78

4.3 Model ages and crustal processes 80

4.3.1 Sedimentary systems 80

4.3.2 Meta-sedimentary systems 82

4.3.3 Meta-igneous systems 83

4.3.4 Partially melted systems 84

4.4 The crustal-growth problem 85

4.4.1 Crustal-accretion ages 85

4.4.2 Sediment-provenance ages 87

4.4.3 Archean depleted mantle 88

4.4.4 Early Archean crustal provinces 89

4.5 Nd in the oceans 91

4.5.1 Modern seawater Nd 92

4.5.2 Ancient seawater Nd 93

4.5.3 Tertiary seawater Nd 94

4.5.4 Quaternary seawater Nd 95

5 Lead isotopes 101

5.1 U-Pb isochrons 101

5.1.1 U-Pb dating of carbonates 102

5.2 U-Pb (zircon) dating 103

5.2.1 Lead-loss models 104

5.2.2 Upper intersection ages 105

5.2.3 Ion-microprobe analysis 107

5.2.4 Lead 207/206 ages 109

5.2.5 Inherited zircon 111

5.2.6 Alternative presentations of U-Pb data 112

5.2.7 Alternative U-Pb dating materials 113

5.3 Common (whole-rock) Pb-Pb dating 115

5.3.1 The geochron 116

5.4 Model (galena) ages 118

5.4.1 The Holmes-Houtermans model 118

5.4.2 Conformable leads 119

5.4.3 Open-system Pb evolution 120

5.5 Pb-Pb dating and crustal evolution 123

5.5.1 Archean crustal evolution 123

5.5.2 Paleo-isochrons and metamorphic disturbance 124

5.6 Environmental Pb 126

5.6.1 Anthropogenic Pb 127

5.6.2 Pb as an oceanographic tracer 128

5.6.3 Paleo-seawater Pb 130

6 Isotope geochemistry of oceanic volcanics 136

6.1 Isotopic tracing of mantle structure 136

6.1.1 Contamination and alteration 136

6.1.2 Disequilibrium melting 138

6.1.3 Mantle plumes 139

6.1.4 Plum-pudding mantle 140

6.1.5 Marble-cake mantle 141

6.2 The Nd-Sr isotope diagram 141

6.2.1 Box models for MORB sources 142

6.2.2 The mantle array and OIB sources 144

6.2.3 Mantle convection models 146

6.3 Pb isotope geochemistry 148

6.3.1 Pb-Pb isochrons and the lead paradox 149

6.3.2 The development of HIMU 151

6.3.3 The terrestrial Th/U ratio 151

6.3.4 The upper-mantle [mu] value re-examined 155

6.4 Mantle reservoirs in isotopic multispace 156

6.4.1 The mantle plane 156

6.4.2 The mantle tetrahedron 157

6.5 Identification of mantle components 160

6.5.1 HIMU 160

6.5.2 EMII 161

6.5.3 EMI 162

6.5.4 Kinematic models for mantle recycling 163

6.5.5 Depleted OIB sources 164

6.6 Island arcs and mantle evolution 165

6.6.1 Two-component mixing models 166

6.6.2 Three-component mixing models 168

7 Isotope geochemistry of continental rocks 174

7.1 Mantle xenoliths 174

7.1.1 Mantle metasomatism 176

7.2 Crustal contamination 178

7.2.1 Two-component mixing models 178

7.2.2 Melting in natural and experimental systems 180

7.2.3 Inversion modelling of magma suites 182

7.2.4 Lithospheric mantle contamination 186

7.2.5 Phenocrysts as records of magma evolution 188

7.3 Petrogenesis of continental magmas 188

7.3.1 Kimberlites, carbonatites and lamproites 188

7.3.2 Alkali basalts 190

7.3.3 Flood basalts 191

7.3.4 Precambrian granitoids 195

7.3.5 Phanerozoic batholiths 197

8 Osmium isotopes 203

8.1 Osmium analysis 203

8.2 The Re-Os and Pt-Os decay schemes 204

8.2.1 The Re decay constant 204

8.2.2 Meteorite isochrons 205

8.2.3 Dating ores and rocks 206

8.2.4 Os normalisation and the Pt-Os decay scheme 208

8.3 Mantle osmium 209

8.3.1 Bulk Silicate Earth 209

8.3.2 Lithospheric evolution 210

8.3.3 Primitive upper mantle 213

8.3.4 Enriched plumes 214

8.3.5 Osmium from the core 216

8.3.6 Asthenospheric mantle heterogeneity 218

8.4 Petrogenesis and ore genesis 219

8.4.1 The Bushveld Complex 219

8.4.2 The Stillwater Complex 220

8.4.3 The Sudbury Igneous Complex 222

8.4.4 Flood-basalt provinces 223

8.5 Seawater osmium 223

8.5.1 Seawater Os isotope evolution 224

8.5.2 Os fluxes and residence times 225

9 Lu-Hf and other lithophile isotope systems 232

9.1 Lu-Hf geochronology 232

9.1.1 The Lu decay constant and the CHUR composition 232

9.1.2 Dating metamorphism 234

9.2 Mantle Hf evolution 235

9.2.1 Hf zircon analysis 235

9.2.2 Archean sediments 236

9.2.3 Western Greenland 237

9.2.4 Mantle depletion and recycling 239

9.2.5 Sediment recycling 242

9.3 Seawater hafnium 244

9.4 The La-Ce and La-Ba systems 245

9.4.1 La-Ba geochronology 246

9.4.2 La-Ce geochronology 246

9.4.3 Ce isotope geochemistry 247

9.5 The K-Ca system 249

10 K-Ar and Ar-Ar dating 254

10.1 The K-Ar dating method 254

10.1.1 Analytical techniques 254

10.1.2 Inherited argon and the K-Ar isochron diagram 257

10.1.3 Argon loss 258

10.2 The [superscript 40]Ar-[superscript 39]Ar dating technique 259

10.2.1 [superscript 40]Ar-[superscript 39]Ar measurement 259

10.2.2 Irradiation corrections 260

10.2.3 Step heating 260

10.2.4 Argon-loss events 262

10.2.5 Excess argon 264

10.2.6 Dating paleomagnetism: a case study 265

10.2.7 [superscript 39]Ar recoil 267

10.2.8 Dating glauconite and clay minerals 268

10.3 Laser-probe dating 269

10.3.1 Method development 269

10.3.2 Applications of laser-probe dating 271

10.4 Timescale calibration 272

10.4.1 The magnetic-reversal timescale 272

10.4.2 The astronomical timescale 274

10.4.3 Intercalibration of decay constants 275

10.5 Thermochronometry 276

10.5.1 Arrhenius modelling 276

10.5.2 Complex diffusion models 279

10.5.3 K-feldspar thermochronometry 282

11 Rare-gas geochemistry 291

11.1 Helium 291

11.1.1 Mass spectrometry 291

11.1.2 Helium production in nature 292

11.1.3 Terrestrial primordial helium 293

11.1.4 The 'two-reservoir'

model 294

11.1.5 Crustal helium 298

11.1.6 Helium and volatiles 300

11.1.7 Helium and interplanetary dust 301

11.2 Neon 303

11.2.1 Neon production 303

11.2.2 Solar neon in the earth 304

11.2.3 Neon and helium 306

11.3 Argon 307

11.3.1 Terrestrial primordial argon 307

11.3.2 Neon-argon 311

11.3.3 Argon-38 313

11.4 Xenon 314

11.4.1 Iodogenic xenon 314

11.4.2 Fissiogenic xenon 317

11.4.3 Solar xenon 318

12 U-series dating 324

12.1 Secular equilibrium and disequilibrium 324

12.2 Analytical methods 325

12.2.1 Mass spectrometry 327

12.3 Daughter-excess methods 328

12.3.1 [superscript 234]U dating of carbonates 328

12.3.2 [superscript 234]U dating of Fe-Mn crusts 330

12.3.3 [superscript 230]Th sediment dating 331

12.3.4 [superscript 230]Th-[superscript 232]Th 332

12.3.5 [superscript 230]Th sediment stratigraphy 334

12.3.6 [superscript 231]Pa-[superscript 230]Th 335

12.3.7 [superscript 210]Pb 338

12.4 Daughter-deficiency methods 339

12.4.1 [superscript 230]Th: theory 339

12.4.2 [superscript 230]Th: applications 340

12.4.3 [superscript 230]Th: dirty calcite 343

12.4.4 [superscript 231]Pa 345

12.5 U-series dating of open systems 346

12.5.1 [superscript 231]Pa-[superscript 230]Th 346

12.5.2 ESR-[superscript 230]Th 347

13 U-series geochemistry of igneous systems 353

13.1 Geochronology of volcanic rocks 354

13.1.1 The U-Th isochron diagram 354

13.1.2 Ra-Th isochron diagrams 356

13.1.3 U-series model age dating 358

13.2 Magma-chamber evolution 359

13.2.1 The Th isotope evolution diagram 359

13.2.2 Short-lived species in magma evolution 360

13.3 Mantle-melting models 363

13.3.1 Melting under ocean ridges 363

13.3.2 The effect of source convection 365

13.3.3 The effect of melting depth 367

13.3.4 The effect of source composition 369

13.3.5 Evidence from short-lived species 370

13.3.6 Evidence for mantle upwelling rates 372

13.3.7 Evidence from Th-Sr and Th-U mantle arrays 373

13.3.8 Evidence for crustal melting and contamination 374

13.3.9 Sources of continental magmas 375

13.4 Subduction-zone processes 376

13.4.1 U-Th evidence 376

13.4.2 Ra-Th evidence 378

14 Cosmogenic nuclides 383

14.1 Carbon-14 383

14.1.1 [superscript 14]C measurement by counting 385

14.1.2 The closed-system assumption 386

14.1.3 The initial-ratio assumption 386

14.1.4 Dendrochronology 387

14.1.5 Production and climatic effects 389

14.1.6 Radiocarbon in the oceans 391

14.1.7 The 'Ocean Conveyor Belt' 393

14.2 Accelerator mass spectrometry 395

14.2.1 Radiocarbon dating by AMS 396

14.3 Beryllium-10 398

14.3.1 [superscript 10]Be in the atmosphere 399

14.3.2 [superscript 10]Be in soil profiles 399

14.3.3 [superscript 10]Be in snow and ice 401

14.3.4 [superscript 10]Be in the oceans 402

14.3.5 Comparison of [superscript 10]Be with other tracers 405

14.3.6 [superscript 10]Be in magmatic systems 407

14.4 Chlorine-36 410

14.5 Iodine-129 413

14.6 In situ cosmogenic isotopes 414

14.6.1 Al-26 meteorite exposure ages 414

14.6.2 Al-Be terrestrial exposure ages 415

14.6.3 Chlorine-36 exposure ages 417

15 Extinct radionuclides 426

15.1 Production and decay 426

15.2 Extant actinides 426

15.3 Xenon isotopes 429

15.3.1 I-Xe 429

15.3.2 Pu-Xe 431

15.3.3 I-Xe chronology 432

15.4 Very-short-lived species 434

15.4.1 Al-Mg 434

15.4.2 Ca-K 437

15.4.3 Be-10 438

15.5 Short-lived species in planetary differentiation 440

15.5.1 Pd-Ag 440

15.5.2 Mn-Cr 440

15.5.3 Fe-Ni 442

15.5.4 Hf-W 442

15.5.5 [superscript 146]Sm-[superscript 142]Nd 445

15.6 Absent species 446

15.6.1 Cm-U 446

16 Fission-track dating 451

16.1 Track formation 451

16.2 Track etching 453

16.3 Counting techniques 454

16.3.1 The population method 454

16.3.2 The external-detector method 455

16.3.3 Re-etching and re-polishing 456

16.4 Detrital populations 456

16.5 Track annealing 457

16.6 Uplift and subsidence rates 459

16.7 Track-length measurements 462

16.7.1 Projected tracks 465

16.7.2 Confined tracks 466

16.8 Pressure effects 468.

Notes:

Includes bibliographical references and index.

ISBN:

0521823161

0521530172

OCLC:

53953791

Online:

Publisher description