Stable Isotope Geochemistry

by Valley, John W.; Cole, David R.; Mineralogical Society of America

• ISBN13: 9780939950553
• ISBN10: 0939950553
• Format: Paperback
• Copyright: 2001-10-01
• Publisher: De Gruyter

Table of Contents

Equilibrium Oxygen, Hydrogen and Carbon Isotope Fractionation Factors Applicable to Geologic Systems
Thomas Chacko
David R. Cole
Juske Horita
Introduction	1	(1)
Theoretical Background	2	(4)
Comparison of cation and isotope exchange reactions	2	(1)
Quantum mechanical reasons for isotopic fractionation	3	(3)
Calculating Fractionation Factors	6	(9)
Theory	6	(2)
An example calculation	8	(3)
Calculation of fractionation factors for gases, liquids and fluids	11	(1)
Calculation of fractionation factors for minerals	12	(3)
Variables Influencing the Magnitude of Fractionation Factors	15	(15)
Temperature	15	(3)
Pressure	18	(3)
Mineral composition	21	(3)
Solution composition	24	(6)
Methods of Calibrating Fractionation Factors	30	(10)
Semi-empirical bond-strength calibration	30	(3)
Natural sample calibration	33	(2)
Experimental calibration	35	(5)
Summary of Fractionation Factors	40	(9)
Oxygen isotope fractionation factors	40	(6)
Carbon isotope fractionation factors	46	(2)
Hydrogen isotope fractionation factors	48	(1)
Conclusions	49	(1)
Acknowledgments	50	(1)
References	50	(12)
Appendices	62	(21)
Rates and Mechanisms of Isotopic Exchange
David R. Cole
Sumit Chakraborty
Introduction	83	(4)
Background	83	(1)
Objectives	84	(3)
General Kinetic Concepts of Isotopic Exchange	87	(8)
Concentration-dependent isotopic rate equation	87	(2)
Activity-dependent isotopic rate equation	89	(3)
Temperature-dependence of rate constants: activation energy and entropy	92	(2)
Compensation law and the isokinetic temperature	94	(1)
Isotopic Exchange in Gaseous and Aqueous Systems	95	(15)
General background	95	(2)
Activity-dependent considerations	97	(1)
Rates of isotopic exchange between gases	98	(7)
Rates of isotopic exchange in aqueous solutions	105	(5)
Reaction-Controlled Mineral-Fluid Isotope Exchange	110	(16)
Chemical reaction versus diffusion	110	(1)
Rate models	111	(5)
Surface area, grain size and fluid-to-solid ratio	116	(3)
Influence of solution composition	119	(1)
Pressure effect	120	(2)
Activation parameters and empirical correlation with mineral chemistry	122	(4)
Diffusion-Controlled Mineral-Fluid Isotope Exchange	126	(28)
Fick's laws	127	(2)
Diffusion coefficients	129	(1)
Determination of D	130	(13)
Factors influencing diffusion	143	(9)
Empirical methods	152	(2)
Diffusion-Controlled Melt(Glass)-Volatile Isotope Exchange	154	(17)
The mode of transport-diffusion versus percolation	155	(1)
Glasses versus melts: the glass transition	156	(1)
The diffusion equation in glasses/melts	157	(3)
Diffusion caused by gradients other than chemical: electrical, stress and thermal	160	(1)
Water diffusion in SiO2 glass: a prototype for a wide range of behavior	160	(2)
Diffusion of water and other hydrogen-bearing species in natural molten systems	162	(2)
Diffusion of C and S related species	164	(1)
Diffusion of oxygen: new results	165	(4)
Pressure-dependence of diffusion rates	169	(2)
Summary and Recommendations	171	(1)
Acknowledgments	172	(1)
References	172	(19)
Appendix --- Tables 1-4	191	(34)
Fractionation of Carbon and Hydrogen Isotopes in Biosynthetic Processes
John M. Hayes
Isotope Fractionation	225	(47)
Isotope in reaction networks	226	(4)
Further general factors affecting isotopic compositions	230	(1)
Isotopic compositions of compound classes relative to biomass	231	(3)
Isotopic compositions of carbohydrates	234	(12)
Isotopic compositions of amino acids	246	(10)
Isotopic compositions of nucleic acids	256	(1)
Isotopic compositions of tetrapyrroles	257	(1)
Isotopic compositions of lipids	258	(14)
Epilogue	272	(1)
Acknowledgments	273	(1)
References	273	(6)
Stable Isotope Variations in Extraterrestrial Materials
Kevin D. McKeegan
Laurie A. Leshin
Introduction	279	(8)
Isotope cosmochemistry of the light stable isotopes	280	(6)
Analysis methods	286	(1)
Stable Isotope Records in Primitive Materials	287	(18)
Hydrogen	288	(3)
Oxygen	291	(14)
Stable Isotope Records in Evolved Materials	305	(5)
Moon	305	(1)
Mars	306	(4)
Unresolved Issues and Future Directions	310	(1)
Acknowledgments	311	(1)
References	311	(8)
Oxygen Isotope Variations of Basaltic Lavas and Upper Mantle Rocks
John M. Eiler
Introduction	319	(1)
Guiding Principles	319	(1)
Early Studies of Oxygen Isotope Variations in Mafic Igneous Rocks	320	(1)
Isotopic Fractionations Relevant to Study of Mantle Rocks and Basaltic Lavas	321	(11)
Experimental, theoretical and empirical constraints on fractionation factors	321	(5)
Oxygen-isotope systematics of crystallization, partial melting and degassing	326	(1)
Crystallization	327	(2)
Partial melting	329	(2)
Devolatilization	331	(1)
Isotopic Signatures of Crustal Contaminants and Subducted Lithosphere	332	(4)
Oceanic crust and sediments	332	(2)
Subduction-zone metamorphic rocks	334	(1)
Upper continental crust	334	(1)
Lower continental crust	335	(1)
Oxygen Isotope Compositions of Mantle Peridotites	336	(1)
Mid-Ocean Ridge Basalts	337	(3)
Oceanic Intraplate Basalts	340	(12)
Survey of ocean islands	341	(3)
High 3He/4He	344	(1)
Detailed studies	345	(7)
Continental Intraplate Basalts	352	(1)
Arc-Related Lavas	352	(5)
Summary and Future Directions	357	(2)
View of the crust/mantle system through stable isotope geochemistry	357	(1)
Outstanding problems and future directions	358	(1)
Acknowledgments	359	(1)
References	359	(6)
Stable Isotope Thermometry at High Temperatures
John W. Valley
Introduction	365	(1)
Requirements of Stable Isotope Thermometry	365	(1)
Analysis of Stable Isotope Ratios	366	(2)
Calibration of Isotope Fractionation	368	(1)
Kinetics of Mineral Exchange	369	(4)
Apparent temperature	369	(1)
Diffusion	370	(2)
Effect of deformation	372	(1)
Effect of water fugacity	372	(1)
Diffusion Models	373	(6)
Diffusion distance	373	(1)
Dodson's closure temperature	374	(1)
The Giletti model	375	(1)
The Fast Grain Boundary diffusion model (FGB)	376	(1)
The mode effect	377	(2)
Strategies for Successful Thermometry	379	(2)
Isotope exchange trajectories	379	(1)
RAM thermometers	380	(1)
Microscopic versus macroscopic models	381	(1)
Tests of Thermometry	381	(4)
Concordance	381	(1)
δ-δ and δ-Δ diagrams	382	(1)
Imaging	382	(1)
The outcrop test	383	(1)
Microanalysis	384	(1)
Correlations to mode or crystal size	385	(1)
Oxygen Isotope Thermometry	385	(6)
RAM thermometers	385	(1)
Aluminosilicate-quartz	386	(2)
Magnetite-quartz	388	(3)
Rutile-quartz	391	(1)
Carbon Isotope Thermometry	391	(8)
Calcite-graphite	391	(2)
Graphite crystallinity and morphology	393	(3)
Carbonate/graphite ratio	396	(1)
Contact and polymetamorphism	396	(1)
Fluid flow	397	(1)
Other minerals	398	(1)
Biogenic versus abiogenic graphite	398	(1)
Adirondack Mountains---A case study	398	(1)
Sulfur Isotope Thermometry	399	(1)
Skarns	400	(1)
One-Mineral Thermometers	400	(2)
Acknowledgments	402	(1)
References	402	(13)
Stable Isotope Transport and Contact Metamorphic Fluid Flow
Lukas P. Baumgartner
John W. Valley
Introduction	415	(2)
Abbreviations and symbols	416	(1)
``Closed System'' Metamorphic Volatilization	417	(1)
Batch Volatilization	417	(4)
Rayleigh volatilization	419	(1)
Dehydration	420	(1)
Mixed volatile reactions	420	(1)
Coupled O-C Depletions	421	(2)
Open System Fluid-Rock Interaction: Continuum Mechanics Models of Stable Isotope Transport in High Temperature Crustal Systems	423	(7)
The mass balance equation for stable isotope transport	427	(3)
Mathematical Formulation of the Transport Mechanisms	430	(4)
The transport equation	433	(1)
Fluid-Rock Interaction: The Time Dependence of the System's Isotopic Composition	434	(16)
Geologically relevant insights from simple analytical solutions to the stable isotope transport equations	438	(12)
Continuum Mechanics and Fluid-Rock Ratios	450	(3)
Contact Metamorphism	453	(6)
Volatilization during contact metamorphism	453	(1)
Fluid infiltration during contact metamorphism	454	(2)
An example: The Alta contact aureole	456	(3)
Future Work: Merging the Results of Modeling and Microanalysis	459	(1)
Acknowlegments	460	(1)
References	461	(8)
Stable Isotopes in Seafloor Hydrothermal Systems: Vent fluids, hydrothermal deposits, hydrothermal alteration, and microbial processes
W. C. Shanks, III
Introduction	469	(3)
Methods	472	(6)
Geologic Setting of Seafloor Hydrothermal Systems	478	(3)
Seafloor Hydrothermal Vent Fluids	481	(7)
Oxygen and hydrogen isotopes in vent fluids	483	(1)
Sulfur isotopes in vent fluids	484	(2)
Carbon isotopes in vent fluids	486	(2)
Stable Isotope Systematics of Selected Seafloor Hydrothermal Systems	488	(28)
Bare volcanic ridges: 21°N, 9-10°N, and 17-22°S EPR	489	(7)
Deep reaction zones: 504B	496	(3)
Oceanic gabbros: Hess Deep and Southwest Indian Ridge	499	(1)
Shallow alteration zones and seawater entrainment: TAG	499	(3)
Serpentinization	502	(4)
Sedimented ridges	506	(4)
Rifted continental settings	510	(3)
Convergent margins	513	(3)
Summary and Conclusions	516	(1)
Eruptive events	516	(1)
Magmatic components	516	(1)
Phase separation	516	(1)
Deep biosphere	517	(1)
Acknowledgments	517	(1)
References	517	(10)
Oxygen- and Hydrogen-Isotopic Ratios of Water in Precipitation: Beyond Paleothermometry
Richard B. Alley
Kurt M. Cuffey
Introduction	527	(1)
Basis of Paleothermometry Using Oxygen- and Hydrogen-Isotopic Ratios of Water	528	(6)
Complications	534	(5)
Source effects on δ18O or δD of precipitation	534	(3)
Path effects on δ18O or δD of water in precipitation	537	(1)
Sampling and other site effects	538	(1)
Case Studies	539	(9)
Central Greenland	539	(8)
Southern Africa	547	(1)
Discussion	548	(1)
Acknowledgments	549	(1)
References	550	(5)
Isotopic Evolution of the Biogeochemical Carbon Cycle During the Precambrian
David J. Des Marais
Introduction	555	(1)
The Present-Day Carbon Cycle	556	(3)
The hydrosphere-atmosphere-biosphere (HAB) sub-cycle	556	(1)
The sedimentary (SED) sub-cycle	557	(1)
The metamorphic (MET) sub-cycle	558	(1)
The mantle-crust (MAN) sub-cycle	558	(1)
Isotopic Indicators of Carbon Budgets and Processes	559	(5)
Biological isotopic discrimination	559	(1)
Isotopic mass balance and the sedimentary cycle	559	(1)
Preservation of the carbon isotopic record	560	(4)
The Archean Record	564	(4)
Planetary processes, climate and the carbon cycle	564	(1)
Archean biosphere	564	(4)
The Late Archean to Proterozoic Transition	568	(4)
Changes in the carbon cycle	568	(1)
Marine sedimentation on the Kaapvaal Craton: a glimpse of carbon isotopic patterns at the dawn (2.5-2.3 Ga) of the Proterozoic Eon	568	(2)
Isotopic change from late Archean to Mesoproterozoic (2.7-1.7 Ga)	570	(2)
The Mesoproterozoic Record (1.8-1.0 Ga)	572	(1)
The Neoproterozoic Record (0.8-0.54 Ga)	572	(1)
The C Cycle, O2 and the Evolution of Eukarya	573	(1)
Future Work	574	(1)
Acknowledgments	574	(1)
References	574	(5)
Isotopic Biogeochemistry of Marine Organic Carbon
Katherine H. Freeman
Introduction	579	(1)
Marine Inorganic Carbon	579	(4)
Production of Marine Organic Matter	583	(7)
The photosynthetic isotope effect	583	(2)
The photosynthetic isotope effect and studies of paleoenvironmental change	585	(2)
Organic carbon in marine surface waters	587	(1)
Trophic effects and ecosystem studies	588	(2)
Marine Sedimentary Organic Matter	590	(5)
Alteration of primary isotopic signatures	590	(2)
The bulk of sedimentary organic matter: an unresolved issue	592	(1)
Microbial influences on marine sedimentary organic matter δ13C values	593	(2)
Sedimentary Records of Past Environments	595	(2)
Acknowledgments	597	(1)
References	597	(10)
Biogeochemistry of Sulfur Isotopes
D. E. Canfield
Introduction	607	(2)
Microbial Processes	609	(1)
Assimilatory sulfate reduction	609	(1)
Dissimilatory Sulfate Reduction	610	(8)
Ecological and phylogenetic diversity of sulfate reducers	610	(1)
Principles governing the extent of fractionation	611	(3)
Magnitude of fractionation during sulfate reduction by pure cultures	614	(1)
Fractionation at high temperatures	615	(1)
Isotope fractionation during sulfate reduction in nature	616	(2)
Sulfide Oxidation	618	(5)
Fractionations during sulfide oxidation	618	(2)
Disproportionation of sulfur intermediate compounds	620	(1)
Isotope fractionation during disproportionation	621	(2)
Isotopic Composition of Sedimentary Sulfides	623	(4)
Minor sulfur isotopes	627	(1)
Fractionation Calculations	627	(2)
A Few Specific Applications	629	(3)
The isotope record of sedimentary sulfides	629	(2)
Biogenic sulfides and microscale isotope analysis	631	(1)
Organic sulfur	632	(1)
Concluding Remarks	632	(1)
Acknowledgments	633	(1)
References	633	(4)
Stratigraphic Variation in Marine Carbonate Carbon Isotope Ratios
Robert L. Ripperdan
Introduction	637	(2)
The Marine Carbon Cycle	639	(3)
The short-term carbon cycle	640	(1)
The long-term carbon cycle	641	(1)
Isotopic Variation Within The Long-Term Marine Carbon Cycle	642	(11)
General principles	642	(1)
The general mass balance model for marine carbon	643	(2)
Variation in the burial flux of marine organic carbon	645	(1)
Continental weathering of carbon	646	(1)
Silicate weathering	647	(2)
Volcanic and metamorphic emissions of CO2	649	(1)
Clathrate hydrates and sedimentary methane	650	(1)
Stratigraphic variation by other means: confounding factors	651	(2)
A Detailed Look at a Large Transient Δ13C Event: The Late Ordovician Glaciation and Mass Extinction	653	(5)
Late Ordovician δ13C variation in the Hanson Creek Formation, central Nevada	654	(3)
Models for the Late Ordovician positive δ13C excursion	657	(1)
Summary	658	(1)
Acknowledgments	658	(1)
References	658