Stable isotopes in high temperature geological processes / R.N.Clayton et al.; ed. by J.W.Valley, H.P.Taylor, J.R. O'Neil. - Washington: Mineralogical Society of America, 1986. - xvi, 570 p.: ill. - (Reviews in mineralogy; vol.16). - Bibliogr. at the end of the chapters. - ISBN 0-939950-20-0; ISSN 0275-0279  Место хранения:   033 | Бурятский научный центр | Улан-Удэ | Центральная научная библиотека

Оглавление / Contents

COPYRIGHT; ADDITIONAL COPIES ................................... ii FOREWORD; DEDICATION .......................................... iii PREFACE ......................................................... v Chapter 1 THEORETICAL and EXPERIMENTAL ASPECTS of ISOTOPIC FRACTIONATION James R. O'Neil PNTRODUCnON ..................................................... 1 KINETIC and EQUILIBRIUM ISOTOPE EFFECTS ......................... 2 Kinetic Isotope Effects ...................................... 2 Equilibrium Isotope Effects .................................. 3 The FRACTIONATION FACTOR ..................................... 4 The PARTITION FUNCTION ....................................... 5 Translational Partition Function ............................. 7 Rotational Partition Function ................................ 8 Vibrational Partition Function ............................... 8 CALCULATION of EQUILIBRIUM CONSTANTS for ISOTOPE EXCHANGE REACTION ........................................................ 9 Gases ........................................................ 9 FACTORS INFLUENCING the SIGN and MAGNITUDE of α ................ 13 Temperature ................................................. 13 Chemical Composition ........................................ 16 Crystal Structure ........................................... 18 Pressure .................................................... 19 LABORATORY DETERMINATIONS of ISOTOPIC FRACTIONATION FACTORS .... 20 Two-direction Approach ...................................... 20 Sample calculation of 103lnα ................................ 22 Pseudo isotope exchange reactions ........................... 23 Problems with the two-directional method .................... 23 Partial Exchange Technique .................................. 24 Three-Isotope Method ........................................ 25 Stable Isotope Fractionation Curves ......................... 28 STABLE ISOTOPE THERMOMETRY .................................. 28 Scope ....................................................... 28 Tests for Equilibrium ....................................... 30 Present Status .............................................. 31 CONCLUSIONS .................................................... 33 ACKNOWLEDGMENTS ................................................ 36 REFERENCES ..................................................... 37 Chapter 2 KINETICS of ISOTOPIC EXCHANGE at ELEVATED TEMPERATURES and PRESSURES David R. Cole & Hiroshi Ohmoto INTRODUCTION ................................................... 41 BASIC CONCEPTS in ISOTOPE EXCHANGE REACTIONS ................... 42 Homogeneous versus Heterogeneous Reactions .................. 42 Rate Law for Isotope Exchange Reactions ..................... 44 Determination of Rf from F and Its Relation to kf, the True Rate Constant ............................................... 47 Determination of D, the Diffusion Coefficient ............... 49 The bulk exchange technique ................................. 52 Microbeam analytical techniques ............................. 55 MECHANISMS and RATES of ISOTOPE EXCHANGE in HOMOGENEOUS SYSTEMS ........................................................ 57 Kinetics of Isotopic Exchange Reactions in Solutions ........ 58 The sulfate-sulfide system .................................. 58 The sulfate-water system .................................... 60 Kinetics of Isotopic Exchange Reactions Between Gases ....... 61 MECHANISMS and RATES of ISOTOPE EXCHANGE REACTIONS in HETEROGENEOUS SYSTEMS .......................................... 63 Isotope Exchange Accompanying Surface Reactions ............. 63 Rate model .................................................. 74 Rates and activation parameters ............................. 74 The relationship between rf and water/solid ratio ........... 76 Isotope Exchange Accompanying Diffusion ..................... 77 The effect of temperature on rates of diffusion ............. 78 Effects of pressure on the rates of diffusion ............... 81 Anisotropy in diffusion ..................................... 83 Water in minerals ........................................... 83 Comparison of the Surface-Reaction and Diffusion Models ..... 84 SUMMARY ........................................................ 86 ACKNOWLEDGMENTS ................................................ 87 Chapter 3 ISOTOPIC EXCHANGE in OPEN and CLOSED SYSTEMS Robert T. Gregory & Robert E.С. INTRODUCTION ................................................... 91 BASIC PRINCIPLES ............................................... 92 Isotopic Exchange Reactions ................................. 92 Delta Space ................................................. 92 Conservation of Mass ........................................ 93 CLOSED SYSTEMS .............................................. 93 General Statement ........................................... 93 Representation in Delta Space ............................... 93 Temperature Effects ......................................... 97 Transformation to Other Coordinate Systems .................. 98 Δ-Δ plots ................................................... 99 δ-Δ plots ................................................... 99 Isotherm plots ............................................. 101 Summary: Closed Systems .................................... 101 OPEN SYSTEMS ............................................... 101 General Statement .......................................... 101 Elementary rate law ........................................ 103 "Closed" system exchange model ............................. 103 "Buffered" open system exchange model ...................... 106 Interpretation of the Kinetic Models ....................... 107 Fluid/rock ratios .......................................... 107 Exchange trajectories versus isochronous arrays ............ 108 Calculation of effective fluid/rock ratios from disequilibrium arrays ...................................... 110 Summary: Open Systems ...................................... 111 APPLICATIONS to NATURAL SYSTEMS ............................... 111 General Statement .......................................... 111 Plagioclase-Pyroxene from Layered Gabbros .................. 112 Primary magmatic compositions .............................. 113 Temperatures of fluid-rock interactions .................... 113 Fluid/rock ratios .......................................... 114 Fluid isotopic compositions and pathlines .................. 114 Mineral Pairs from Granitic Rocks .......................... 114 Precambrian Siliceous Iron Formation: Quartz-Magnetite ..... 116 Mineral Pair Systematics Applied to Upper Mantle Assemblages ................................................ 120 Eclogite mineral pairs ..................................... 120 Peridotite mineralpairs .................................... 122 Impact of an open system model on the evolution of the upper mantle ............................................... 123 Summary: Natural Systems ................................... 124 CLOSING STATEMENT ............................................. 124 ACKNOWLEDGMENTS ............................................... 125 REFERENCES .................................................... 126 Chapter 4 HIGH TEMPERATURE ISOTOPE EFFECTS in the EARLY SOLAR SYSTEM Robert N. Clayton INTRODUCTION .................................................. 129 PLANETARY PROCESSES ........................................... 129 Achondrites and the Moon ................................... 129 Ordinary Chondrites ........................................ 131 Carbonaceous Chondrites .................................... 131 NEBULAR PROCESSES ............................................. 132 Evaporation and Condensation ............................... 132 Isotopic Anomalies ......................................... 134 FUN Inclusions ................................................ 137 REFERENCES .................................................... 139 Chapter 5 STABLE ISOTOPE VARIATIONS in the MANTLE T. Kurtis Kyser INTRODUCTION .................................................. 141 OXYGEN ISOTOPE COMPOSITIONS ................................... 142 Mafic Lavas ................................................ 142 Mantle Xenoliths ........................................... 144 Processes Controlling the 180/160 Ratio of the Mantle ...... 146 Ancient Oxygen Isotope Compositions ........................ 152 CARBON ........................................................ 152 NITROGEN ...................................................... 155 SULFUR ........................................................ 157 HYDROGEN ...................................................... 158 CONCLUDING REMARKS ............................................ 160 REFERENCES .................................................... 162 Chapter 6 CHARACTERIZATION and ISOTOPIC VARIATIONS in NATURAL WATERS Simon M.F. Sheppard INTRODUCTION .................................................. 165 Concept of Combined Isotope Approach ....................... 165 Definition of Principal Water Types ........................ 166 ISOTOPIC CHARACTERISTICS of NATURAL WATERS .................... 167 Ocean Waters ............................................... 167 Present-day ............................................. 167 Ancient ................................................. 167 Meteoric Waters ............................................ 168 Present-day ............................................. 168 Ancient ................................................. 170 Connate and Formation Waters ............................... 172 Metamorphic Waters ......................................... 173 Magmatic Waters ............................................ 174 Organic Waters ............................................. 175 Hydrothermal Waters ........................................ 177 Other Waters ............................................... 178 CONCLUSIONS ................................................ 179 ACKNOWLEDGMENTS ............................................... 180 REFERENCES .................................................... 181 Chapter 7 MAGMATIC VOLATILES: ISOTOPIC VARIATION of C, H, and S Bruce E. Taj INTRODUCTION .................................................. 185 SOLUBILITY, SPECIATION, and CHEMICAL COMPOSITION .............. 185 Solubility and Speciation .................................. 185 Carbon .................................................. 185 Hydrogen ................................................ 186 Sulfur .................................................. 187 С, Н, and S and Mafic Glasses .............................. 187 С, Н, and S in Felsic Glasses .............................. 189 ISOTOPIC FRACTIONATION and MIGRATION of VOLATILES ............. 190 Isotopic Fractionation ..................................... 190 Carbon .................................................. 190 Hydrogen ................................................ 190 H2O and hydrous minerals ................................ 190 H2O and hydrous magmas .................................. 191 Sulfur .................................................. 195 Isotopic Variation During Magmatic Processes ............... 195 Contamination-assimilation .............................. 196 Contamination-exchange .................................. 196 Degassing ............................................... 196 Volatile Migration in Magmas ............................... 197 CARBON ISOTOPES ............................................... 198 Volcanic Gases ............................................. 198 Carbon dioxide .......................................... 198 Methane ................................................. 201 Carbon Dioxide in Vesicles ................................. 201 Carbon Isotopes in Basaltic Glass .......................... 201 Carbon in Mafic and Felsic Rocks ........................... 204 HYDROGEN ISOTOPES ............................................. 204 Volcanic Gases ............................................. 204 H2O in Fluid Inclusions .................................... 207 Mafic Magmas ............................................ 207 Felsic Magmas ........................................... 207 Hydrogen Isotopes in Basaltic Glasses ...................... 207 Hydrogen Isotopes in Felsic Plutons ........................ 211 SULFUR ISOTOPES ............................................... 213 Volcanic Gases ............................................. 213 Basalts .................................................... 214 Andesites .................................................. 218 CONCLUSIONS ................................................ 218 ACKNOWLEDGMENTS ............................................... 219 REFERENCES .................................................... 220 Chapter 8 IGNEOUS ROCKS: I. PROCESSES of ISOTOPIC FRACTIONATION and ISOTOPE SYSTEMATICS Hugh P.Taylor, Jr. & Simon M.F. Sheppard INTRODUCTION .................................................. 227 GENERAL 18O/160 and D/H VARIATIONS in IGNEOUS ROCKS ............ 229 PRIMORDIAL ISOTOPE RATIOS ..................................... 230 Oxygen Isotopes ............................................ 230 Hydrogen Isotopes .......................................... 231 CLOSED-SYSTEM EFFECTS ......................................... 233 Rayleigh Fractionation versus Equilibrium Crystallization ............................................ 233 Equilibrium 18O/160 Fractionations between Crystals and Melt ....................................................... 234 Evidence from Natural Igneous-Rock Suites .................. 237 Mineral-Melt D/H Fractionations and Magmatic Differentiation Effects .................................... 239 OPEN-SYSTEM PROCESSES ......................................... 241 The Effcls of Assimilation ................................. 241 Oxygen Isotope Effects ..................................... 244 Radiogenic Isotope Effects ................................. 242 87Sr-18O Effects during Assimilation-Fractional Crystallization ............................................ 246 Adamello Massif, Northern Italy ............................ 249 EXCHANGE EFFECTS at the MARGINS of MAGMA BODIES ............... 249 SOURCE-ROCK RESERVOIRS AND MELT GENERATION .................... 252 Isotopic Compositions of Possible Source Rocks ............. 252 Oceanic crust ........................................... 252 Sedimentary rocks ....................................... 252 Metasedimentary rocks ................................... 253 Archean cratons ......................................... 253 Granulite-facies lower continental crust ................ 253 Upper mantle ............................................ 253 Preexisting igneous rocks ............................... 254 Low-18O rocks formed by meteoric-hydrothermal alteration .............................................. 254 Formation waters or marine waters ....................... 254 Source Contamination versus Crustal Contamination .......... 254 Summary .................................................... 256 LOW-18O MAGMAS ............................................. 256 LOW- and HIGH-DEUTERIUM MAGMAS ............................. 259 The VOLCANIC ROCKS of ITALY ................................... 260 General Features ........................................... 260 Alban Hills Volcanic Center ................................ 260 M. Vulsini Volcanic Center ................................. 263 Mixing Models Involving Tuscan Basement Rocks .............. 265 Summary .................................................... 266 ACKNOWLEDGMENTS ............................................... 268 REFERENCES .................................................... 269 Chapter 9 IGNEOUS ROCKS: II. ISOTOPIC CASE STUDIES of CIRCUMPACIFIC MAGMATISM Hugh P. Taylor, Jr. INTRODUCTION .................................................. 273 CALC-ALKALINE VOLCANIC ROCKS in the ANDEAN CORDILLERA ......... 273 18O/160 Ratios in Late Cenozoic Andean Volcanic Rocks ....... 273 The Central Volcanic Zone (CVZ) in Peru .................... 277 The Northern Volcanic Zone (NVZ) in Colombia and Ecuador ... 278 Comparison of the NVZ and the Peruvian CVZ ................. 279 Comparison of the Southern CVZ with the SVZ and AVZ ........ 281 Summary .................................................... 284 The PENINSULAR RANGES BATHOLITH (PRB) of SOUTHERN and BAJA CALIFORNIA .................................................... 286 General Statement .......................................... 286 18O/160 Ratios ............................................. 288 Other Isotopic and Geochemical Gradients ................... 291 Origin of the Isotopic Variations in the PRB Г)4San Jacinto-Santa Rosa Mountains Block ......................... 292 OTHER CRETACEOUS GRANITIC BATHOLITHS in the UNITED STAT ....... 294 Relationship to the Peninsular Ranges Batholith ............ 295 Regional Isotopic Systematics .............................. 296 Idaho Batholith ............................................ 297 Summary .................................................... 300 OXYGEN and STRONTIUM ISOTOPE STUDIES of WESTERN PACIFIC ISLAND ARCS ................................................... 300 Geologic Setting and Sources of Data ....................... 300 Mariana and Volcano Arcs ................................... 301 Japan and Izu Arcs ......................................... 303 SiO2, versus K2O ........................................... 304 ORIGIN of LOW 18O RHYOLITE MAGMAS in WESTERN NORTH AMERICA .... 306 General Statement .......................................... 306 Catastrophic Isotopic Changes in Magmas During Caldera Collapse, Yellowstone Volcanic Field ....................... 306 Origins of the Low-18O Magmas in the Yellowstone Caldera Complex .................................................... 308 Low-18O Rhyolite Magmas Elsewhere in the Western U.S.A. .... 312 The Low-18O Magma Problem .................................. 314 Emplacement into a rift-zone tectonic setting ........... 314 Chemical composition .................................... 315 ACKNOWLEDGMENTS ............................................... 315 REFERENCES .................................................... 316 Chapter 10 IGNEOUS ROCKS: III. ISOTOPIC CASE STUDIES of MAGMATISM in AFRICA, EURASIA and OCEANIC ISLAN Simon M.F. Sheppard INTRODUCTION .................................................. 319 ANOROGENIC MAGMATISM .......................................... 319 Oceanic Islands ............................................ 319 North Atlantic or Brito-Arctic Igneous Province ............ 323 Primary unmodified magmatic isotopic compositions ....... 324 Low-18O magmas .......................................... 326 Gardar Igneous Province .................................... 329 Granitic Rocks of East and South China ..................... 332 Alkaline Ring ~ Complexes in Africa and Arabia ............. 335 Arabian complexes ....................................... 336 Ring-complexes of Cameroon and Nigeria .................. 337 OROGENIC MAGMATISM ............................................ 342 Plutonic Belts of the Himalaya-Transhimalaya ............... 342 Transhimalaya batholith ................................. 344 High, north and "Lesser Himalaya" belts ................. 346 Variscan Magmatism ......................................... 349 180/160 ratios and type of magmatism ..................... 349 Nature of source materials .............................. 353 Caledonian Magmatism of Northern Britain ................... 356 Younger basic intrusions ................................ 358 'Older' and 'younger' granites .......................... 359 Archaean Granites of Southern Africa ....................... 362 Concluding Remarks ......................................... 365 ACKNOWLEDGMENTS ............................................... 367 REFERENCES .................................................... 368 Chapter 11 METEORIC-HYDROTHERMAL SYSTEMS Robert E. Criss & Hugh P. Taylor, Jr. INTRODUCTION .................................................. 373 FLUID DYNAMICS in a PERMEABLE MEDIUM .......................... 374 Basic Principles ........................................... 374 Free Convection ............................................ 375 Permeability and Porosity .................................. 379 Theoretical Scaling Law, Cooling Times, and Water/Rock Ratios ..................................................... 383 MODERN METEORIC-HYDROTHERMAL SYSTEMS .......................... 387 Geologic Settings of Geothermal Systems .................... 387 Origin and Composition of Geothermal Fluids ................ 387 Physical State of Geothermal Fluids ........................ 391 ISOTOPIC EFFECTS in HYDROTHERMALLY-ALTERED ROCKS ........... 393 Stable Isotopic Systematics of Altered Rocks ............... 393 Effects of Alteration on Geochronologic Systems ............ 395 FOSSIL METEORIC-HYDROTHERMAL SYSTEMS .......................... 397 General Occurrence and Character ........................... 397 Isotopic Relationships in the Skaergaard Intrusion ......... 400 Numerical Modeling of the Skaergaard Intrusion ............. 402 Water/Rock Ratios in the Skaergaard Intrusion .............. 405 Lake City Caldera .......................................... 407 Idaho Batholith ............................................ 408 Yankee Fork District ....................................... 411 Meteoric-Hydrothermal Ore Deposits ......................... 411 PETROGRAPHIC, CHEMICAL, and PHYSICAL ASPECTS of ROCK ALTERATION .................................................... 413 Volcanic Country Rocks ..................................... 413 Granitic Plutons ........................................... 415 Layered Gabbro Bodies ...................................... 417 Contrasting Effects in Gabbros and Granites ................ 418 SUMMARY ....................................................... 420 ACKNOWLEDGMENTS ............................................... 421 REFERENCES .................................................... 422 Chapter 12 ALTERATION of the OCEANIC CRUST and the 18O HISTORY of SEAWATER Karlis Muehlenbachs INTRODUCTION .................................................. 425 CURRENT SEA FLOOR PROCESSES ................................... 426 Low Temperature Processes .................................. 426 High Temperature Processes ................................. 428 Metavolcanic rocks ...................................... 428 Dikes ................................................... 429 Gabbros ................................................. 429 Plagiogranites .......................................... 431 ON-LAND EXPOSURES of the SEA FLOOR ......................... 431 MID-OCEAN RIDGE HOT SPRINGS ................................ 435 MODELLING OF MID-OCEAN RIDGE HYDROTHERMAL SYSTEMS .......... 436 180 BUDGET at MID-OCEAN RIDGES .............................. 437 18δ0 of Ancient Oceans ...................................... 439 REFERENCES ................................................. 443 Chapter 13 STABLE ISOTOPE GEOCHEMISTRY of METAMORPHIC John W. Valley INTRODUCTION .................................................. 445 ISOTOPIC THERMOMETRY .......................................... 445 METAMORPHIC VOLATILIZATION .................................... 446 Batch Volatilization ....................................... 447 Rayleigh Volatilization .................................... 448 Dehydration ................................................ 450 Decarbonation .............................................. 451 Mixed Volatile Reactions ................................... 451 Coupled O-C Depletions ..................................... 452 CONTACT METAMORPHISM .......................................... 454 Volatilization During Contact Metamorphism ................. 458 Fluid Infiltration During Contact Metamorphism ............. 461 Controls of permeability ................................ 461 Calculation of fluid/rock ratios ........................ 463 Skarn ...................................................... 464 The Effects of Variable P-T or Disequilibrium .............. 465 Polythermal exchange .................................... 465 Graphitization .......................................... 465 REGIONAL METAMORPHISM ......................................... 467 Fluid Convection During Regional Metamorphism .............. 470 Isotopic Exchange by Diffusion and Recrystallization ....... 471 The Scale of Oxygen Isotope Exchange During Regional Metamorphism ............................................... 473 Granulite Facies Metamorphism .............................. 475 The role of fluids in granulite genesis ................. 475 δ18O and δ13C in granulites .............................. 476 The Adirondacks as a case study ......................... 478 Low- and high-180 granulites; low-180 eclogites .......... 480 ACKNOWLEDGMENTS ............................................... 481 REFERENCES .................................................... 486 Chapter 14 STABLE ISOTOPE GEOCHEMISTRY of ORE DEPOSITS Hiroshi Ohmoto INTRODUCTION .................................................. 491 APPLICATIONS of STABLE ISOTOPES as GEOTHERMOMETERS ............ 493 Hydrogen Systems ........................................... 493 Oxygen Systems ............................................. 494 Carbon Systems ............................................. 494 Sulfur Systems ............................................. 494 HYDROGEN and OXYGEN ISOTOPE GEOCHEMISTRY of HYDROTHERMAL SYSTEMS ....................................................... 495 Methods of Estimating the 5D and 5180 of Ore Fluids ........ 495 Hydrogen and Oxygen Isotopic Characteristics of Reference Waters ..................................................... 496 Hydrogen and Oxygen Isotopic Characteristics of Recycled Waters ..................................................... 498 Isotopic Zoning in Wall Rocks .............................. 502 Problems in the Quantification of Water/Rock Ratios ........ 502 Quantification of Hydrological and Geochemical Nature of Ore-forming Systems ........................................ 505 CONTRASTS BETWEEN CARBON-SULFUR and HYDROGEN-OXYGEN SYSTEMATICS ................................................... 505 Causes of Isotopic Variation ............................... 506 Isotopic Equilibrium ....................................... 506 Isotopic Effects during Mineralization ..................... 506 Multiple Sources ........................................... 507 CARBON ISOTOPE GEOCHEMISTRY of HYDROTHERMAL SYSTEMS ........ 508 Isotopic Variation during Geochemical Cycles of Carbon in Near-surface Environments .................................. 508 Carbon Isotopic Composition of the Mantle .................. 509 Isotopic Relationships among Aqueous Carbon Species ........ 509 Methods of Determining the Sources of Carbon in Ore Deposits ................................................... 512 SULFUR ISOTOPE GEOCHEMISTRY of HYDROTHERMAL SYSTEMS ........ 513 Sulfur Isotopic Characteristics of Reference Reservoirs .... 513 Sulfur Isotopic Characteristics of Recycled Seawater-sulfur ............................................ 513 Isotopic Relationships Among Aqueous Sulfur Species ........ 518 Sulfur Isotopic Relationships Between Fluid Species and Minerals and Between Co-existing Minerals .................. 520 Methods of Determining the Sources of Sulfur in Ore Deposits ................................................... 523 SULFUR ISOTOPES in MAGMATIC SYSTEMS ........................... 528 Speciation and Solubility of Sulfur in Silicate Melts ...... 528 δ34S Values of Mantle-derived Igneous Rocks ................ 530 Assimilation of Crustal Sulfur by Mafic Magmas and the Formation ofCu-Ni Sulfide Ores ............................. 532 Assimilation of Crustal Sulfur by Felsic Magmas ............ 534 Sulfur Isotopic Characteristics of Magmatic Fluids ......... 537 GENETIC MODELS for ORE DEPOSIT TYPES .......................... 537 Porphyry and Skam Type Deposits ............................ 539 Base- and Precious-metal Veins, and Replacement Deposits ... 540 Massive Sulfide Deposits of Submarine Volcanic Association ................................................ 542 Shale/Carbonate-hosted Zn-Pb Deposits ...................... 544 Mississippi Valley-type Deposits ........................... 545 Red-bed Associated Cu Deposits ............................. 551 CONCLUDING REMARKS ............................................ 553 ACKNOWLEDGMENTS ............................................... 555 REFERENCES .................................................... 556 Appendix: TERMINOLOGY and STANDARDS James R. O'Neil TERMINOLOGY ................................................... 561 The δ Value ................................................... 561 Isotope Exchange Reactions ................................. 561 The Fractionation Factor, α ................................ 562 103lnα and the Δ Value ..................................... 563 Thee Value ................................................. 564 Fractionation Curves ....................................... 564 Crossovers ................................................. 565 Reversals .................................................. 565 STANDARDS ..................................................... 565 Oxygen ..................................................... 565 Hydrogen ................................................... 567 Carbon ..................................................... 567 Sulfur ..................................................... 569 REFERENCES .................................................... 569