WATER in NOMINALLY ANHYDROUS MINERALS 62 Reviews in Mineralogy and. Geochemistry 62 TABLE OF CONTENTS 1 Analytical Methods for Measuring Water in Nominally Anhydrous Minerals George R. Rossman INTRODUCTION 1 ANALYTICAL METHODS 2 Early infrared studies 2 Quantitative IR methods 3 Mineral specific calibrations 8 Thermogravimetric methods 9 P205 cell coulometry 9 Hydrogen extraction with uranium reduction methods 10 Nuclear methods for hydrogen determination 11 Nuclear magnetic resonance 16 Secondary ion mass spectrometry (SIMS) 18 PREVIOUS REVIEWS OF METHODS 20 SURFACE WATER 21 CURRENT STATUS OF CALIBRATIONS 23 GLASSES 23 ACKNOWLEDGMENTS 24 REFERENCES 24 2 The Structure of Hydrous Species in Nominally Anhydrous Minerals: Information from Polarized IR Spectroscopy Eugen Libowitzky and Anton Beran INTRODUCTION 29 The importance of hydrous species in NAMs 29 Why use IR spectroscopy? 30 History 30 CONCEPTS OF INFRARED SPECTROSCOPY 31 Introduction to IR spectroscopy 31 Sample requirements 32 ix Water in Nominally Anhydrous Minerals - Table of Contents Experimental equipment 32 QUANTITATIVE DATA FROM INFRARED SPECTROSCOPY 33 The distance - frequency correlation of hydrogen bonds 33 The spatial orientation of hydrous species 34 Total absorbance: a first step towards quantitative water analysis 35 CONCEPTS OF STRUCTURAL MODELS FROM INFRARED DATA 36 Charge balance and substitution 36 Electrostatic considerations on defect geometry 37 Space requirements: ideal and distorted models 38 Influence on band energies from cation substitution 38 Discrimination among hydrous defects 39 Deuteration 40 I XAMl'l I S 40 Vesuvianite: orientation and hydrogen bonding of hydroxyl groups 40 4 Hydrogarnet substitution - the (OH)4 ~ cluster 41 Water molecules in structural cavities: beryl and cordierite 43 OH substitution in topaz 44 OH incorporation in diopside 44 OH defects in perovskite 47 OH traces in corundum 48 ACKNOWLEDGMENTS 49 REFERENCES 49 3 Structural Studies of OH in NominallyAnhydrous Minerals Using NMR Simon C. Kohti INTRODUCTION 53 PRINCIPLES OF SOI ID STATE NMR 54 Positions of 'H MAS NMR resonances 55 Widths of 'H MAS NMR resonances 55 Intensity of 'H MAS NMR resonances 56 APPLICATION OF II MAS NMR TO NOMINALLY ANHYDROUS MINERALS 58 Attractive features of 'H MAS NMR for studies of NAMs 58 Problems and difficulties in applying 'H MAS NMR to NAMs 58 'H MAS NMR studies of orthopyroxene 59 'H MAS NMR studies of clinopyroxene 60 'H MAS NMR studies of olivine 60 'H MAS NMR studies of garnet 61 'H MAS NMR studies of Si02 polymorphs 61 'H MAS NMR studies of feldspars and other aluminosilicate framework minerals... 61 'H MAS NMR studies of wadsleyite 62 NON-SPINNING II NMR EXPERIMENTS 62 STUDIES OF OTHER NUCLEI IN NAMS 63 PROSPECTS FOR FUTURE DEVELOPMENT OF NMR FOR STUDIES OF NAMS 65 ACKNOWLEDGMENTS 65 REFERENCES 65 x Water in Nominally Anhydrous Minerals - Table of Contents in Nominally Anhydrous Minerals Kate Wright INTRODUCTION 67 POINT 1)11 I ( I S IN MINERALS 67 THEORETICAL BACKGROUND 69 Quantum mechanical methods 69 Classical methods 70 Treatment of defects 71 OH DEFECTS IN MANTLE SILICATES 72 The Mg2Si04 polymorphs 73 Pyroxene 79 GENERAL REMARKS AND FUTURE DIRECTIONS 80 ACKNOWLEDGMENTS 81 REFERENCES 81 5 Hydrogen in High Pressure Silicate and Oxide Mineral Structures Joseph R. Smyth INTRODUCTION 85 GEOCHEMISTRY OF H 85 CRYSTAL CHEMISTRY OF H 86 NOMINALLY HYDROUS HIGH-PRESSURE SILICATE PHASES 87 Brucite 90 Serpentine 90 Talc 90 True micas 91 Chlorite 92 Amphiboles 92 Lawsonite 92 Epidote 93 Humite 94 Clinohumite 94 Chondrite 94 Phase A 95 Phase B 96 Superhydrous Phase B 96 Phase D 96 Phase E 97 Phase Pi 97 Topaz-OH 98 Phase Egg 98 K-cymrite 98 xi Water in Nominally Anhydrous Minerals - Table of Contents NOMINALLY ANHYDROUS HIGH-PRESSURE SILICATE AND OXIDE PHASES 99 Periclase-wiistite 99 Corundum 99 Coesite 101 Stishovite and rutile 101 Pyroxenes 102 Akimotoite 103 Garnet 104 Olivine 104 Wadsleyite 105 Wadsleyite II 106 Ringwoodite 106 Anhydrous phase B 107 Kyanite 107 Perovskite 108 Post-perovskite 108 Zircon 109 Titanite 110 CONCLUSIONS 110 ACKNOWLEDGMENT 110 REFERENCES 110 6 Water in Nominally Anhydrous Crustal Minerals: Speciation, Concentration, and Geologic Significance Elizabeth A. Johnson INTRODUCTION 117 Importance of nominally anhydrous minerals in the crust 117 Scope and goals of this chapter 117 HYDROUS SPECIES AND CONCENTRATIONS IN CRUSTAL MINERALS 118 Quartz and coesite 118 Feldspars and nepheline 119 Pyroxenes 122 Garnets 123 Al2Si05 polymorphs 124 Rutile and cassiterite 126 Zircon and titanite 128 Cordierite and beryl 129 UNDERSTANDING GEOLOGIC SYSTI MS 130 Thermodynamic properties 130 Physical properties 134 The water budget of the Earth 136 SUMMARY AND FUTURE POSSIBILITIES 136 ACKNOWLEDGMENTS 137 REFERENCES 137 APPENDIX 142 Studies of hydrogen in quartz 143 xii Water in Nominally Anhydrous Minerals - Table of Contents Geological studies of H20 and C02 in cordierite 143 Hydrous species in feldspars 144 Structural hydroxyl concentrations in crustal and mantle pyroxenes 146 Structural hydroxyl concentrations in crustal garnets 148 Structural hydroxyl concentrations in kyanite 152 Structural hydroxyl concentrations in sillimanite 152 Structural hydroxyl concentration in andalusite 153 Structural hydroxyl concentrations in rutile 153 Structural hydroxyl concentrations in cassiterite 154 7 Water in Natural Mantle Minerals I: Pyroxenes Henrik Skogby INTRODUCTION 155 OH ABSORPTION BANDS IN IR SPECTRA 156 Diopside 156 Augite 156 Omphacite 157 Orthopyroxene 157 Absorption from inclusions 158 CORRELATIONS OF OH AND SAMPLE CHEMISTRY 159 WATER CONCENTRATION IN MANTLE PYROXENES 162 IMPLICATIONS FOR WATER IN THE UPPER MANTLE 164 ACKNOWLEDGMENTS 165 REFERENCES 166 8 Water in Natural Mantle Minerals II: Olivine, Garnet and Accessory Minerals Anton Beran and Eugen Libowitzky INTRODUCTION 169 OLIVINE 170 Basic structure and possible sites of hydrogen incorporation 170 Defect types in mantle-related olivines from different localities 171 Calibration approaches and summary of hydrogen contents 176 GARNET 176 Structural and spectral features 176 Calibration and hydrogen content 180 \( ( I SSORY MINERALS 182 Kyanite 182 Rutile 184 Coesite 185 Spinel 186 Zircon 186 ACKNOWLEDGMENTS 188 REFERENCES 188 xiii Water in Nominally Anhydrous Minerals - Table of Contents 7 Thermodynamics of Water Solubility and Partitioning Hans Keppler and Nathalie Bolfan-Casanova INTRODUCTION 193 BASIC THERMODYNAMICS OF WATER SOLUBILITY AND PARTITIONING 194 The meaning of the term "water solubility" 194 Thermodynamics of water solubility 195 Relationship between water solubility and partitioning 198 EXPERIMENTAL STRATEGIES FOR MEASURING WATER SOLUBILITY AND WATER PARTITION ( Oi l 1 l( U N I S 199 Annealing experiments 199 Crystallization experiments 200 WATER IN UPPER MANTLE MINERALS 201 Water solubility in and the A1 content of orthopyroxenes as "geohygrometer" 201 Water solubility in olivine 205 Water solubility in garnet 211 Water solubility in clinopyroxene 211 Water partitioning among upper mantle minerals 212 Water storage capacity of the upper mantle and the origin of the Earth's asthenosphere 214 Water recycling by subducted slabs 215 WATER IN TRANSITION ZONE MINERALS 216 Water solubility in wadsleyite and water partitioning between wadsleyite and olivine 216 Partitioning of water between wadsleyite and ringwoodite 219 Partition coefficients of water between other high-pressure phases 220 WATER IN MINERALS OF THE LOWER MANTLE 222 Water in ferropericlase 222 Water in magnesium silicate perovskite 223 The distribution of water at the 660 km discontinuity 225 THE EQUILIBRIUM DISTRIBUTION OF WATER IN THE EARTH'S INTERIOR 226 ACKNOWLEDGMENTS 227 REFERENCES 227 10 The Partitioning of Water Between Nominally Anhydrous Minerals and Silicate Melts Simon C. Kohn and Kevin J. Grant INTRODUCTION 231 PARTITIONING OF WATER BETWEEN NAMS AND MELTS; METHODOLOGY AND APPROACH 233 Experimental studies of water partitioning between NAMs and melts 233 SUMMARY, IMPLICATIONS AND FUTURE RESEARCH 238 ACKNOWLEDGMENTS 239 REFERENCES 239 xiv Water in Nominally Anhydrous Minerals - Table of Contents Daniel J. Frost INTRODUCTION 243 MANTLE METASOMATISM 244 EVIDENCE 1 ROM MANTLE XI NOI I I IIS 246 Peridotite massifs and xenoliths from alkaline basalts 247 Xenoliths from kimberlites 247 Mantle amphibole mineralogy 248 Mantle mica mineralogy 250 EXPERIMENTAL STUDIES ON THE STABILITY OF KNOWN MANTLE HYDROUS MINERALS 251 Pargasitic amphiboles 251 Apatite 255 Phlogopite 256 K-richterite 259 EXPERIMENTAL STUDIES ON THE STABILITY OF POTENTIAL HIGH PRESSURE HYDROUS MANTLE MINERALS 260 Phase X 261 Humite and dense hydrous magnesium silicate phases 262 THE STABILITY OF HYDROUS PHASES IN ULTRAMAFIC LITHOSPHERE AND THE CONVECTING MANTLE 262 ACKNOWLEDGMENTS 265 REFERENCES 266 1 2 Hydrous Phases and Water Transport in the Subducting Slab Tatsuhiko Kawamoto INTRODUCTION 273 LOW-PRESSURE HYDROUS MINERALS AND HIGH-PRESSURE HYDROUS PHASES 273 STABILITY OF HYDROUS PHASES IN DOWNGOING PERIDOTITE 277 STABILITY OF HYDROUS PHASES IN DOWNGOING BASALT AND SEDIMENT 279 PRESSURE - TEMPERATURE CONDITIONS AND DEHYDRATION REACTIONS IN THE SUBDUCTING SLAB 280 COMPOSITION AND DIHEDRAL ANGLES OF AQUEOUS FLUIDS IN MANTLE PERIDOTITE 281 SECOND CRITICAL ENDPOINT BETWEEN MAGMAS AND AQUEOUS FLUID: IMPLICATIONS FOR SLAB-DERIVED COMPONENT .282 CONCLUDING REMARKS 285 ACKNOWLEDGMENT 286 REFERENCES 286 xv Water in Nominally Anhydrous Minerals - Table of Contents I «3 Diffusion of Hydrogen in Minerals Jannick Ingrin and Marc Blanchard