Non-Traditional Stable
Isotopes
82
Reviews in Mineralogy and Geochemistry
82
TABLE OF CONTENTS
1
Non-Traditional Stable Isotopes: Retrospective and Prospective
Fang-Zhen Teng, Nicolas Dauphas, James M. Watkins
INTRODUCTION.....................................................................................................................1
THE δ NOTATION..................................................................................................................3
GUIDELINES FOR SELECTING REFERENCE MATERIALS.............................................4
EMERGING ISOTOPE SYSTEMS..........................................................................................6
Stable potassium isotope geochemistry..........................................................................7
Titanium isotope geochemistry......................................................................................8
Vanadium isotope geochemistry...................................................................................10
Stable rubidium isotope geochemistry.........................................................................11
Stable strontium isotope geochemistry.........................................................................11
Cadmium isotope geochemistry...................................................................................13
Tin isotope geochemistry.............................................................................................15
Antimony isotope geochemistry...................................................................................15
Stable tellurium isotope geochemistry.........................................................................16
Barium isotope geochemistry.......................................................................................16
Stable neodymium isotope geochemistry.....................................................................18
CONCLUSIONS......................................................................................................................20
ACKNOWLEDGMENTS........................................................................................................20
REFERENCES........................................................................................................................20
2
Equilibrium Fractionation of Non-traditional Isotopes:
a Molecular Modeling Perspective
Marc Blanchard, Etienne Balan, Edwin A. Schauble
INTRODUCTION...................................................................................................................27
THEORETICAL FRAMEWORK...........................................................................................28
Equilibrium fractionation theory..................................................................................28
Approximate formula based on force constants...........................................................33
MODELING APPROACHES..................................................................................................35
Quantum-mechanical molecular modeling..................................................................35
Theoretical studies of non-traditional stable isotope fractionation..............................37
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Modeling isotopic properties of liquid phases.............................................................40
Beyond harmonic approximation: Path integral molecular dynamics..........................43
MÖSSBAUER AND NRIXS SPECTROSCOPY....................................................................45
MASS-INDEPENDENT FRACTIONATION
AND VARIATIONS IN MASS LAWS...................................................................................47
Variability in mass laws for common fractionations....................................................48
Mass-independent fractionation in light elements (O and S).......................................50
Mass-independent fractionation in non-traditional elements (Hg, Tl, and U).............50
Mass-independent fractionation signatures in heavy elements,
versus light elements.................................................................................................53
Ab initio methods for calculating field shift fractionation factors................................53
Isomer shifts from Mössbauer spectroscopy................................................................55
CONCLUSIONS......................................................................................................................55
ACKNOWLEDGMENTS........................................................................................................56
REFERENCES........................................................................................................................56
3
Equilibrium Fractionation of Non-Traditional Stable Isotopes:
an Experimental Perspective
Anat Shahar, Stephen M. Elardo, Catherine A. Macris
INTRODUCTION...................................................................................................................65
FACTORS INFLUENCING EQUILIBRIUM FRACTIONATION FACTORS......................66
PROOF OF EQUILIBRIUM IN ISOTOPE EXPERIMENTS................................................67
Time series....................................................................................................................67
Multi-direction approach..............................................................................................68
Three-isotope exchange method...................................................................................69
Kinetic effects...............................................................................................................72
EXPERIMENTAL METHODS...............................................................................................73
Low temperature experiments......................................................................................73
High temperature, low pressure experiments...............................................................74
High temperature and pressure experiments................................................................76
NRIXS and diamond anvil cell experiments................................................................78
POST-EXPERIMENT ANALYSIS.........................................................................................80
CONCLUSIONS......................................................................................................................80
ACKNOWLEDGMENTS........................................................................................................81
REFERENCES........................................................................................................................81
4
Kinetic Fractionation of Non-Traditional Stable Isotopes
by Diffusion and Crystal Growth Reactions
James M. Watkins, Donald J. DePaolo, E. Bruce Watson
INTRODUCTION...................................................................................................................85
Organization of the article............................................................................................86
ISOTOPE FRACTIONATION BY DIFFUSION....................................................................86
Expressions for diffusive fluxes....................................................................................87
Isotopic mass dependence of diffusion in “simple” systems........................................87
Isotopic mass dependence of diffusion in aqueous solution........................................88
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Isotopic mass dependence of diffusion in silicate melts..............................................90
Isotopic mass dependence of diffusion in minerals and metals...................................92
DIFFUSIVE BOUNDARY LAYERS IN THE GROWTH MEDIUM....................................94
ISOTOPE FRACTIONATION BY COMBINED REACTION AND DIFFUSION.............102
General framework for crystal growth from an infinite solution................................102
Crystal growth and kinetic isotope effects.................................................................105
Interpreting the model parameters..............................................................................107
Stable isotope fractionation during electroplating......................................................110
Stable isotope fractionation of trace elements............................................................113
THE ROLE OF THE NEAR SURFACE OF CRYSTALS....................................................115
The growth entrapment model (GEM).......................................................................116
The surface reaction kinetic model (SRKM), growth entrapment model (GEM),
and isotopes.............................................................................................................118
PERSPECTIVES...................................................................................................................120
ACKNOWLEDGMENTS......................................................................................................121
REFERENCES......................................................................................................................121
5
In Situ Analysis of Non-Traditional Isotopes by SIMS and
LA–MC–ICP–MS: Key Aspects and the Example of Mg Isotopes
in Olivines and Silicate Glasses
Marc Chaussidon, Zhengbin Deng, Johan Villeneuve, Julien Moureau, Bruce Watson,
Frank Richter, Frédéric Moynier
INTRODUCTION.................................................................................................................127
Notations used for Mg isotopes..................................................................................128
INSTRUMENTATION FOR IN-SITU STABLE ISOTOPE ANALYSIS.............................128
MC–SIMS analysis.....................................................................................................129
LA–MC–ICP–MS analysis.........................................................................................129
LIMITATIONS FOR IN-SITU STABLE ISOTOPES ANALYSIS.......................................130
Limitations due to the small amount of sample analyzed..........................................131
Limitations due to matrix effects on ion yield............................................................131
Limitations due to instrumental isotopic fractionation...............................................133
STANDARDS AND ANALYTICAL APPROACH USED FOR MG
IN THE PRESENT STUDY..................................................................................................136
Set of standards studied..............................................................................................136
MC–SIMS for Mg isotopic analysis...........................................................................137
LA–MC–ICP–MS for Mg isotopic analysis...............................................................138
Solution MC–ICP–MS for Mg isotopic analysis.......................................................138
MAGNESIUM ION EMISSION DURING IN SITU ANALYSIS.......................................140
Fundamental differences for Mg ion yield between SIMS and
laser ablation ICP–MS.............................................................................................140
Possible origin of the complex matrix effects on ion yield for SIMS .......................143
MAGNESIUM INSTRUMENTAL ISOTOPIC FRACTIONATION....................................145
Similarities and differences for Mg instrumental isotopic fractionation
between SIMS and laser ablation ICP–MS.............................................................145
Matrix effects during ionization of solutions in MC–ICP–MS .................................147
Matrix effects specific to in situ analysis...................................................................149
MEASUREMENT OF THE THREE MAGNESIUM ISOTOPES.......................................152
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The need for high-precision in situ three Mg isotopes analysis in cosmochemistry.. 152
The question of potential isobaric interferences.........................................................153
The question of the mass fractionation law used to correct for instrumental
isotopic fractionation...............................................................................................154
Mg instrumental mass fractionation law for MC–SIMS analyses..............................155
Mg instrumental mass fractionation law for LA–MC–ICP–MS analyses..................158
SUMMARY AND PERSPECTIVES....................................................................................158
ACKNOWLEDGMENTS......................................................................................................159
REFERENCES......................................................................................................................159
6
Lithium Isotope Geochemistry
Sarah Penniston-Dorland,, Xiao-Ming Liu, Roberta L. Rudnick
INTRODUCTION.................................................................................................................165
LITHIUM SYSTEMATICS...................................................................................................167
Li in minerals..............................................................................................................168
Li partitioning.............................................................................................................168
Equilibrium Isotope Fractionation..............................................................................170
Diffusion and kinetic isotopic fractionation...............................................................174
METHODS............................................................................................................................176
Whole rock analyses...................................................................................................176
In situ analyses...........................................................................................................177
EXTRATERRESTRIAL LITHIUM RESERVOIRS.............................................................178
The interstellar medium and the Sun..........................................................................178
Meteorites and their components...............................................................................179
Moon..........................................................................................................................181
TERRESTRIAL LITHIUM RESERVOIRS..........................................................................181
Mantle peridotites.......................................................................................................181
Basalts........................................................................................................................188
Arc lavas.....................................................................................................................190
Continental crust.........................................................................................................191
Seawater.....................................................................................................................192
Rivers..........................................................................................................................193
Lakes..........................................................................................................................193
Groundwater...............................................................................................................194
Hydrothermal fluids....................................................................................................194
IGNEOUS PROCESSES.......................................................................................................195
Differentiation............................................................................................................195
Eruptive processes......................................................................................................196
METAMORPHIC PROCESSES...........................................................................................197
Dehydration................................................................................................................197
Redistribution of Li through fluid infiltration.............................................................198
Diffusion.....................................................................................................................199
CONTINENTAL WEATHERING PROCESSES..................................................................199
Weathering profiles.....................................................................................................201
Rivers..........................................................................................................................201
LITHIUM AS A TRACER OF CONTINENTAL WEATHERING
THROUGH TIME..............................................................................................................204
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FUTURE DIRECTIONS.......................................................................................................205
Weathering processes and Li fractionation experiments............................................205
Continental weathering through time.........................................................................205
Geospeedometry.........................................................................................................206
ACKNOWLEDGMENTS......................................................................................................206
REFERENCES......................................................................................................................206
7
Magnesium Isotope Geochemistry
Fang-Zhen Teng
INTRODUCTION.................................................................................................................219
MAGNESIUM ISOTOPIC ANALYSIS................................................................................221
Nomenclature.............................................................................................................221
Standard and reference materials...............................................................................222
Instrumental Analysis.................................................................................................229
Sample preparation.....................................................................................................229
MAGNESIUM ISOTOPIC SYSTEMATICS
OF EXTRATERRESTRIAL RESERVOIRS......................................................................230
Magnesium isotopic composition of chondrites.........................................................231
Magnesium isotopic composition of differentiated meteorites..................................232
Magnesium isotopic composition of the Moon..........................................................232
MAGNESIUM ISOTOPIC SYSTEMATICS OF THE MANTLE........................................234
Mantle xenoliths.........................................................................................................234
Oceanic basalts...........................................................................................................236
Abyssal peridotites and ophiolites..............................................................................237
Continental basalts.....................................................................................................239
MAGNESIUM ISOTOPIC SYSTEMATICS OF THE OCEANIC CRUST,
CONTINENTAL CRUST AND HYDROSPHERE............................................................241
Magnesium isotopic composition of the oceanic crust..............................................241
Magnesium isotopic composition of the continental crust.........................................243
Magnesium isotopic composition of the hydrosphere................................................247
MAGNESIUM ISOTOPIC SYSTEMATICS OF CARBONATES.......................................250
Abiogenic carbonates.................................................................................................250
Biogenic carbonates...................................................................................................254
Carbonate precipitation experiments and theoretical calculations.............................255
BEHAVIOR OF MAGNESIUM ISOTOPES
DURING MAJOR GEOLOGICAL PROCESSES.............................................................256
Behavior of Mg isotopes during biological processes................................................256
Behavior of Mg isotopes during continental weathering...........................................257
Behavior of Mg isotopes during magmatic differentiation........................................263
Behaviors of Mg isotopes during metamorphic dehydration.....................................264
HIGH-TEMPERATURE MAGNESIUM ISOTOPE FRACTIONATION............................267
High-temperature equilibrium inter-mineral Mg isotope fractionation......................267
Diffusion-driven kinetic Mg isotope fractionation.....................................................270
APPLICATIONS AND FUTURE DIRECTIONS.................................................................276
ACKNOWLEDGMENTS......................................................................................................278
REFERENCES......................................................................................................................278
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8
Silicon Isotope Geochemistry
Franck Poitrasson
ELEMENT PROPERTIES.....................................................................................................289
NOMENCLATURE, REFERENCE MATERIALS AND
ANALYTICAL TECHNIQUES.........................................................................................290
ELEMENTAL AND ISOTOPIC ABUNDANCES IN MAJOR RESERVOIRS...................294
Extraterrestrial reservoirs...........................................................................................294
Terrestrial reservoirs...................................................................................................301
ELEMENTAL AND ISOTOPIC BEHAVIORS
DURING MAJOR GEOLOGICAL PROCESSES.............................................................317
Diffusion, condensation and evaporation...................................................................317
Igneous processes.......................................................................................................322
Metamorphic processes..............................................................................................325
Low temperature processes........................................................................................325
Biological processes...................................................................................................330
IMPORTANT IMPLICATIONS AND FUTURE DIRECTIONS.........................................333
ACKNOWLEDGMENTS......................................................................................................336
REFERENCES......................................................................................................................337
9
Chlorine Isotope Geochemistry
Jaime D. Barnes, Zachary D. Sharp
INTRODUCTION.................................................................................................................345
CHLORINE ISOTOPE NOMENCLATURE AND STANDARDS......................................346
CHLORINE ISOTOPE ANALYTICAL METHODS ...........................................................346
Isotope ratio mass spectrometry (IRMS)....................................................................346
Thermal ionization mass spectrometry (TIMS).........................................................347
Secondary ion mass spectrometry (SIMS).................................................................348
Laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS).........348
ISOTOPIC FRACTIONATION.............................................................................................348
Equilibrium Cl isotope fractionation—theoretical constraints...................................348
Equilibrium Cl isotope fractionation—experimental constraints...............................349
Kinetic Cl isotope fractionation—Cl loss .................................................................351
CHLORINE ISOTOPIC COMPOSITION OF
VARIOUS GEOLOGIC RESERVOIRS ...............................................................................351
Mantle/OIB/mantle derived material..........................................................................351
Seawater and seawater-derived chloride.....................................................................353
Sediments...................................................................................................................355
Altered Oceanic Crust (AOC)....................................................................................355
Serpentinites...............................................................................................................357
Perchlorates................................................................................................................357
Extraterrestrial Materials............................................................................................358
CHLORINE ISOTOPES AS A TRACER .............................................................................364
Tracer through subduction zones................................................................................364
Crustal fluids ..............................................................................................................365
Tracer in ore deposits.................................................................................................368
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Environmental............................................................................................................370
SUMMARY...........................................................................................................................370
ACKNOWLEDGMENTS......................................................................................................371
REFERENCES......................................................................................................................371
10 Chromium Isotope Geochemistry
Liping Qin, Xiangli Wang
INTRODUCTION.................................................................................................................379
Chemical properties of Cr..........................................................................................379
Research History of the Cr isotopic System...............................................................380
ANALYTICAL METHODS AND NOTATION....................................................................382
Analytical methods.....................................................................................................382
Notation......................................................................................................................385
CHROMIUM ISOTOPE COSMOCHEMISTRY..................................................................386
53
Mn–53Cr short-lived chronometer............................................................................386
54
Cr anomalies............................................................................................................387
CHROMIUM ISOTOPIC FRACTIONATION
IN HIGH-TEMPERATURE SETTINGS...........................................................................388
Bulk silicate earth and meteorites..............................................................................388
Serpentinization and metamorphism..........................................................................389
MECHANISMS OF CR ISOTOPIC FRACTIONATION
IN LOW-TEMPERATURE SETTINGS.............................................................................390
Reduction....................................................................................................................390
Equilibrium Cr isotopic fractionation and Cr(III)–Cr(VI) isotope exchange
in aqueous systems..................................................................................................397
Oxidation....................................................................................................................398
Adsorption..................................................................................................................398
Coprecipitation...........................................................................................................398
CHROMIUM ISOTOPIC VARIATIONS IN SURFACIAL ENVIRONMENTS..................399
Groundwater...............................................................................................................399
Weathering systems....................................................................................................399
Rivers and seawater....................................................................................................400
Cr isotope mass balance.............................................................................................401
The Cr isotope system as a paleo-redox proxy...........................................................403
CONCLUDING REMARKS AND OUTLOOK...................................................................407
ACKNOWLEDGEMENT.....................................................................................................408
REFERENCES......................................................................................................................408
11 Iron Isotope Systematics
Nicolas Dauphas, Seth G. John, Olivier Rouxel
INTRODUCTION.................................................................................................................415
METHODOLOGY................................................................................................................417
Rocks and solid samples.............................................................................................418
Water samples.............................................................................................................423
In situ analyses...........................................................................................................424
Isotopic anomalies and mass-fractionation laws........................................................428
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KINETIC AND EQUILIBRIUM FRACTIONATION FACTORS.......................................429
Kinetic processes........................................................................................................430
Equilibrium processes................................................................................................433
IRON ISOTOPES IN COSMOCHEMISTRY.......................................................................451
Nucleosynthetic anomalies and iron-60.....................................................................451
Overview of iron isotopic compositions in extraterrestrial material..........................454
HIGH-TEMPERATURE GEOCHEMISTRY.......................................................................456
Partial mantle melting.................................................................................................462
Impact evaporation and core formation......................................................................464
Fractional crystallization, fluid exsolution, immiscibility, and thermal (Soret)
diffusion...................................................................................................................466
A new tool to improve on geospeedometry reconstructions in igneous petrology....469
IRON BIOGEOCHEMISTRY...............................................................................................470
Microbial cycling of Fe isotopes................................................................................470
Fe isotopes in plants, animals, and humans................................................................472
FLUID–ROCK INTERACTIONS.........................................................................................473
High- and low-temperature alteration processes at the seafloor.................................473
Rivers and soils...........................................................................................................475
Mineral deposits.........................................................................................................475
IRON BIOGEOCHEMICAL CYCLING IN THE MODERN OCEAN...............................477
The importance of iron in the global ocean................................................................477
Sources and sinks for Fe in the ocean........................................................................478
Using Fe isotopes to trace sources of Fe in the oceans..............................................482
Internal cycling of Fe isotopes within the ocean........................................................482
THE GEOLOGICAL RECORD AND PALEOCEANOGRAPHIC APPLICATIONS.........483
The ferromanganese crust record...............................................................................483
Oceanic anoxic events................................................................................................485
The Precambrian record.............................................................................................486
The archive of iron formations...................................................................................486
Black Shales and Sedimentary Pyrite Archives..........................................................490
CONCLUSION......................................................................................................................492
ACKNOWLEDGMENTS......................................................................................................492
REFERENCES......................................................................................................................493
12 The Isotope Geochemistry of Ni
Tim Elliott, Robert C. J. Steele
INTRODUCTION.................................................................................................................511
Notation......................................................................................................................511
NUCLEOSYNTHETIC NI ISOTOPIC VARIATIONS.........................................................513
EXTINCT 60Fe AND RADIOGENIC 60Ni............................................................................520
MASS-DEPENDENT Ni ISOTOPIC VARIABILITY..........................................................526
Magmatic systems......................................................................................................526
Weathering and the hydrological cycle......................................................................532
Biological systems......................................................................................................534
OUTLOOK............................................................................................................................536
ACKNOWLEDGMENTS......................................................................................................537
REFERENCES......................................................................................................................537
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13
The Isotope Geochemistry of Zinc and Copper
Frédéric Moynier, Derek Vance, Toshiyuki Fujii, Paul Savage
INTRODUCTION.................................................................................................................543
METHODS............................................................................................................................545
ZINC AND COPPER ISOTOPE FRACTIONATION FACTORS
FROM AB INITIO METHODS.........................................................................................548
ZINC AND COPPER IN EXTRA-TERRESTRIAL SAMPLES
AND IGNEOUS ROCKS...................................................................................................557
ZINC AND COPPER IN LOW TEMPERATURE GEOCHEMISTRY................................566
Experimental constraints on fractionation mechanisms.............................................568
Cu–Zn isotopes in the weathering–soil–plant system................................................576
The oceans: inputs, outputs and internal cycling of Cu and Zn isotopes...................581
Cu and Zn isotopes in the Anthropocene....................................................................589
ACKNOWLEDGMENTS......................................................................................................591
REFERENCES......................................................................................................................591
14
Germanium Isotope Geochemistry
Olivier J. Rouxel, Béatrice Luais
INTRODUCTION.................................................................................................................601
METHODS............................................................................................................................602
Early methods to measure Ge isotope ratios..............................................................602
State of the art analytical methods.............................................................................603
Sample dissolution issues...........................................................................................605
Chemical purification of samples...............................................................................606
Hydride generation (HG) MC-ICPMS ......................................................................606
Interference issues......................................................................................................607
Notation......................................................................................................................607
Analytical precision ...................................................................................................608
Ge isotope standards and reference materials ...........................................................609
THEORETICAL CONSIDERATIONS AND EXPERIMENTAL CALIBRATIONS..........612
Equilibrium fractionation factors...............................................................................612
Kinetic processes........................................................................................................613
Diffusion of Ge in silicate melts.................................................................................614
HIGH-TEMPERATURE GEOCHEMISTRY.......................................................................616
Fundamentals of Ge high-temperature geochemistry................................................616
Cosmochemistry of Ge isotopes.................................................................................621
GERMANIUM ISOTOPE SYSTEMATICS IN IGNEOUS,
MANTLE-DERIVED ROCKS, AND METAMORPHIC ROCKS....................................626
The Ge isotopic composition of the Earth silicate reservoirs.....................................626
Germanium recycling into the mantle: an attempt to evaluate mantle homogeneity.628
Ore deposits................................................................................................................629
LOW-TEMPERATURE GEOCHEMISTRY.........................................................................631
Fundamentals of Ge low-temperature geochemistry..................................................631
Germanium isotope systematics in low-temperature marine environments...............634
Ge isotope fractionation during low temperature weathering....................................639
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Germanium isotope systematics of hydrothermal waters...........................................639
A preliminary oceanic Ge budget...............................................................................641
The potential for paleoceanography and the rock record...........................................644
CONCLUSION......................................................................................................................647
ACKNOWLEDGMENTS......................................................................................................647
REFERENCES......................................................................................................................648
15 Selenium Isotopes as a Biogeochemical Proxy in Deep Time
Eva E. Stüeken
INTRODUCTION AND OVERVIEW..................................................................................657
NOMENCLATURE, REFERENCE MATERIALS AND ANALYTICAL TECHNIQUES.659
ELEMENTAL AND ISOTOPIC ABUNDANCES IN MAJOR RESERVOIRS...................661
Terrestrial and extraterrestrial igneous terrestrial reservoirs......................................661
Reservoirs at the Earth’s surface................................................................................663
SELENIUM IN BIOLOGY...................................................................................................666
ISOTOPIC FRACTIONATION PATHWAYS........................................................................667
GEOBIOLOGICAL APPLICATIONS..................................................................................670
Developing a mass balance for the modern ocean.....................................................670
Implications and predictions......................................................................................673
Selenium isotopes in deep time..................................................................................674
CONCLUSIONS AND FUTURE DIRECTIONS.................................................................677
ACKNOWLEDGMENTS......................................................................................................677
REFERENCES......................................................................................................................677
16 Good Golly, Why Moly?
The Stable Isotope Geochemistry of Molybdenum
Brian Kendall, Tais W. Dahl, Ariel D. Anbar
INTRODUCTION.................................................................................................................683
ANALYTICAL CONSIDERATIONS...................................................................................684
Data reporting.............................................................................................................684
Chemical separation...................................................................................................685
Mass Spectrometry.....................................................................................................686
CHEMICAL AND BIOLOGICAL CONTEXT....................................................................688
Aqueous geochemistry...............................................................................................688
Biology.......................................................................................................................690
FRACTIONATION FACTORS............................................................................................692
Adsorption to Mn oxides............................................................................................692
Adsorption to Fe oxides and oxyhydroxides..............................................................693
Sulfidic species...........................................................................................................694
Biological processes...................................................................................................694
High-temperature melt systems..................................................................................695
MOLYBDENUM ISOTOPES IN MAJOR RESERVOIRS...................................................696
Meteorites...................................................................................................................696
The mantle and crust..................................................................................................697
The oceans..................................................................................................................699
Lakes..........................................................................................................................706
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APPLICATION TO OCEAN PALEOREDOX......................................................................706
Local depositional conditions.....................................................................................707
Reconstructing the oceanic Mo isotope mass balance...............................................708
Inferring seawater δ98Mo from sedimentary archives.................................................710
Tracing atmosphere–ocean oxygenation using Mo isotopes......................................712
Part 1: Searching for free O2 in the Archean surface environment.............................712
Part 2: Tracing global ocean oxygenation in the post-GOE world.............................714
APPLICATION TO NATURAL RESOURCES....................................................................717
Ore deposits................................................................................................................717
Petroleum systems......................................................................................................722
Anthropogenic tracing................................................................................................722
CONCLUSIONS....................................................................................................................723
ACKNOWLEDGMENTS......................................................................................................724
REFERENCES......................................................................................................................724
17
Recent Developments in Mercury Stable Isotope Analysis
Joel D. Blum, Marcus W. Johnson
INTRODUCTION.................................................................................................................733
Element properties......................................................................................................734
Hg isotope nomenclature............................................................................................734
Reference materials....................................................................................................735
Analytical advances....................................................................................................735
Isobaric and molecular interferences..........................................................................737
Reagent blanks and sample carryover........................................................................740
Matrix effects and the need to remove matrix materials............................................741
Recommendations for analyses..................................................................................744
ISOTOPIC ABUNDANCES IN MAJOR RESERVOIRS.....................................................745
Isotopic behaviors during major geological processes...............................................748
NEW FRONTIERS IN HG ISOTOPE ANALYSIS...............................................................749
Isotopic composition of methyl mercury....................................................................749
Separation of Hg from low concentration waters.......................................................750
Separation of Hg from atmospheric gases..................................................................750
Even-mass MIF..........................................................................................................751
FUTURE DIRECTIONS.......................................................................................................752
ACKNOWLEDGMENTS......................................................................................................753
REFERENCES......................................................................................................................753
18
Investigation and Application of Thallium Isotope Fractionation
Sune G. Nielsen, Mark Rehkämper, Julie Prytulak
ABSTRACT...........................................................................................................................759
INTRODUCTION.................................................................................................................760
METHODOLOGY................................................................................................................762
Mass spectrometry......................................................................................................762
Chemical separation of thallium.................................................................................762
Measurement uncertainties and standards..................................................................764
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THALLIUM ISOTOPE VARIATION IN EXTRATERRESTRIAL MATERIALS..............765
The 205Pb–205Tl decay system......................................................................................765
Chondritic meteorites.................................................................................................766
Iron meteorites............................................................................................................767
Limitations of the 205Pb–205Tl chronometer................................................................770
THALLIUM ISOTOPE COMPOSITION OF THE SOLID EARTH...................................771
The primitive mantle..................................................................................................771
The continental crust..................................................................................................771
THALLIUM ISOTOPE COMPOSITION OF SURFACE RESERVOIRS...........................772
Volcanic degassing.....................................................................................................772
Weathering and riverine transport of Tl......................................................................773
Anthropogenic mobilization of Tl..............................................................................774
The isotope composition of seawater.........................................................................775
THE MARINE MASS BALANCE OF THALLIUM ISOTOPES........................................776
Thallium isotopes in marine input fluxes...................................................................776
Thallium isotope compositions of marine output fluxes............................................780
CAUSES OF THALLIUM ISOTOPE FRACTIONATION...................................................782
APPLICATIONS OF THALLIUM ISOTOPES....................................................................784
Studies of Tl isotopes in Fe–Mn crusts......................................................................784
Calculation of hydrothermal fluid fluxes using Tl isotopes in the ocean crust...........786
High temperature terrestrial applications...................................................................787
FUTURE DIRECTIONS AND OUTLOOK.........................................................................791
REFERENCES......................................................................................................................793
19 Uranium Isotope Fractionation
Morten B. Andersen, Claudine H. Stirling, Stefan Weyer
INTRODUCTION.................................................................................................................799
Uranium occurrence and properties...........................................................................799
Uranium isotopes........................................................................................................800
URANIUM ISOTOPE DETERMINATIONS.......................................................................803
Historical overview of 238U/235U measurements.........................................................803
Chemical preparation of U and mass spectrometric corrections................................804
Anthropogenic U contamination................................................................................804
238
U/235U nomenclature...............................................................................................805
EXPERIMENTAL EVIDENCE FOR URANIUM ISOTOPE FRACTIONATION
PROCESSES.......................................................................................................................806
Experimental studies for nuclear 235U enrichment......................................................806
Uranium isotopes and the nuclear field shift..............................................................806
Experimental evidence for kinetic and equilibrium 238U/235U fractionation...............807
238
U/235U IN COSMOCHEMISTRY......................................................................................809
Uranium isotopic anomalies and the search for extant 247Cm....................................809
Uranium isotope fractionation unrelated to 247Cm decay...........................................813
Pb–Pb chronometer....................................................................................................815
URANIUM ISOTOPE SYSTEMATICS IN HIGH TEMPERATURE
ENVIRONMENTS ON EARTH........................................................................................817
Bulk Earth 238U/235U....................................................................................................817
The mantle..................................................................................................................818
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The continental crust..................................................................................................819
URANIUM ISOTOPES IN ORE DEPOSITS.......................................................................820
Uranium ore types......................................................................................................821
Uranium isotope fractionation in ore deposits...........................................................821
Uranium isotopes as tracers of U mine remediation..................................................824
NEAR-SURFACE U CYCLING AND THE MARINE 238U/235U MASS BALANCE..........825
The 238U/235U in rivers and groundwater.....................................................................826
The 238U/235U of seawater............................................................................................827
The 238U/235U in reducing sediments...........................................................................827
The 238U/235U in marine carbonates.............................................................................831
The 238U/235U of altered oceanic crust.........................................................................832
The 238U/235U of ferromangenese oxides.....................................................................833
Isotopic constraints on the marine U cycle.................................................................834
U ISOTOPES AS A PALEO-REDOX PROXY.....................................................................837
Early Earth redox evolution........................................................................................838
Neo-Proterozoic and Phanerozoic..............................................................................839
OUTLOOK............................................................................................................................841
ACKNOWLEDGMENTS......................................................................................................843
REFERENCES......................................................................................................................843
20
Medical Applications of Isotope Metallomics
Francis Albarède, Philippe Télouk, Vincent Balter
INTRODUCTION.................................................................................................................851
THE ISOTOPE EFFECT.......................................................................................................853
AN OVERVIEW OF Ca, Fe, Zn, Cu, AND S BIOCHEMISTRY AND HOMEOSTASIS...859
Calcium......................................................................................................................859
Iron.............................................................................................................................860
Zinc.............................................................................................................................861
Copper........................................................................................................................862
Sulfur..........................................................................................................................863
ISOTOPE COMPOSITIONS OF Fe–Zn–Cu–S IN THE BLOOD
OF HEALTHY INDIVIDUALS.........................................................................................864
CALCIUM AND BONE LOSS.............................................................................................867
GENETIC AND INFECTIOUS DISEASES.........................................................................868
ISOTOPE METALLOMICS IN CANCER...........................................................................869
ASSESSING THE POTENTIAL OF METAL ISOTOPES AS BIOMARKERS..................875
COMPARTMENTALIZED MODELS OF CELLULAR HOMEOSTASIS.........................877
PERSPECTIVES...................................................................................................................878
ACKNOWLEDGMENTS......................................................................................................879
REFERENCES......................................................................................................................879
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