Inside the Subduction Factory

Inside the Subduction Factory......Page 3
Copyright
......Page 4
CONTENTS......Page 5
PREFACE......Page 7
ANCIENT HISTORY......Page 9
THE LAST BIG THING......Page 10
THE MODERN PARADIGM......Page 12
REFERENCES......Page 13
GENERAL OBSERVATIONS REGARDING SUBDUCTION ZONES......Page 15
THERMAL STRUCTURE OF SUBDUCTION ZONES......Page 16
THERMAL-PETROLOGIC MODELS OF COOL AND WARM SUBDUCTION ZONES......Page 17
CONVECTION IN THE MANTLE WEDGE......Page 19
METAMORPHIC EVOLUTION OF SUBDUCTING SLABS......Page 20
ARC VOLCANISM......Page 23
SEISMOLOGICAL OBSERVATIONS......Page 24
RECENT ADVANCES......Page 25
REFERENCES......Page 27
1. INTRODUCTION......Page 31
2. A WORKING MODEL OF ARC LAVA GEOCHEMISTRY......Page 32
3. OVERVIEW OF INCOMPATIBLE ELEMENT SYSTEMATICS......Page 33
3.1. Depleted Mantle......Page 35
3.2. Two Subduction Components......Page 36
4.1. Trace Element Systematics......Page 37
4.2. Key Sediment Signatures......Page 38
4.3. Nature of Sediment Transport......Page 39
5.1 Trace Element Systematics......Page 40
5.2. Key Signatures of Altered Mafic Oceanic Crust......Page 41
5.3. Nature of Transport of Altered Mafic Crustal Component......Page 43
6. RATES OF PROCESSES AT ARCS......Page 45
APPENDIX A......Page 48
REFERENCES......Page 49
2.1. Fundamentals......Page 54
3.1. Polarization and Rock Properties......Page 55
3.2. Resistivity and Resistance......Page 56
3.4. The Magnetotelluric Method......Page 57
3.5. Modelling Magnetotelluric Data......Page 58
3.6. Case Studies......Page 59
4.1. Refraction and Reflection Surveying......Page 60
4.2. Converted Wave Studies?Receiver Functions......Page 61
5. DISCUSSION AND CONCLUSIONS......Page 62
REFERENCES......Page 63
Seismological Constraints on Structure and Flow Patterns Within the Mantle Wedge......Page 65
2.1. P and S Wave Velocities......Page 66
2.2. Seismic Attenuation......Page 68
2.3. Velocity Anisotropy......Page 69
3. THE SEISMIC VELOCITY AND ATTENUATIONSTRUCTURE OF THE MANTLE WEDGE......Page 70
3.1. Seismic Evidence on the Distribution of Volatiles and Magma Beneath the Volcanic Front......Page 71
3.2. Seismic Structure of Backarc Spreading Centers and Relationship to Arc Structure......Page 74
3.3. The Deep Structure Beneath Back-arc Basins-Evidence for Deep Volatile Release?......Page 75
4.1. A review of Anisotropy Observations in Arcs......Page 77
4.3. Models for Arc Flow Patterns and Relationship to observations......Page 79
5. CONCLUSIONS......Page 82
REFERENCES......Page 83
INTRODUCTION......Page 88
Experimental Background......Page 89
Stress Dependence and Grain Size Dependence in theDiffusion Creep Regime......Page 90
Stress Dependence in the Dislocation Creep Regime: DryConditions......Page 92
Activation Energy for Diffusion Creep: Wet Conditions......Page 93
Pressure Dependence......Page 95
Pressure Dependence Under dry Conditions......Page 96
Combined Water and Pressure Dependence Under wetConditions......Page 98
Grain Boundary Sliding......Page 99
Influence of melt content......Page 100
EXTRAPOLATION OF EXPERIMENTAL DATA TO THEOCEANIC MANTLE AND THE MANTLE WEDGE......Page 102
Viscosity Profiles for the Oceanic Mantle and MantleWedge......Page 103
REFERENCES......Page 107
1. INTRODUCTION......Page 111
2. DISSOLUTION AND SPECIATION OF H2O IN SILICATE MELTS......Page 113
3. PHASE EQUILIBRIA OF HYDROUS PERIDOTITE PARTIAL MELTING......Page 115
4. SEGREGATION OF HYDROUS PARTIAL MELT FROM MANTLE PERIDOTITE......Page 119
5. EFFECT OF H2O ON MELT PRODUCTIVITY......Page 121
6. CONSTRAINTS ON MANTLE MELTING DERIVED FROM PRIMITIVE ARC LAVAS......Page 122
7. MELTING PROCESSES IN THE SUB-ARC MANTLE WEDGE......Page 125
7.1. Anhydrous Decompression Melting......Page 127
7.2. Hydrous Flux Melting......Page 128
REFERENCES......Page 133
INTRODUCTION......Page 139
2. HYDROGEN-RELATED DEFECTS INNOMINALLY ANHYDROUS MINERALS......Page 140
3.2. Grain-boundary Processes......Page 141
4.1. Effects of Water on Anelasticity......Page 142
4.2. Effects of Water on Seismic Wave Velocities......Page 144
4.3. Effects of Water on Seismic Anisotropy......Page 145
5.1. Inferences from Velocity and Attenuation Tomography......Page 148
5.2. Inference from Seismic Anisotropy......Page 149
6.2. Some Remarks on the Use of Seismological Observations to Infer Water Content......Page 151
REFERENCES......Page 153
1. INTRODUCTION......Page 157
2. DATA......Page 158
3. COCOS PLATE SLAB SIGNALS......Page 162
4. FRAMEWORK......Page 163
5. GEOCHEMICAL ZONING......Page 167
6. SEGMENTATION OF THE VOLCANIC FRONT: GEOGRAPHY, VOLUME AND GEOCHEMISTRY......Page 172
7. CONCLUSIONS......Page 175
REFERENCES......Page 176
1. INTRODUCTION......Page 179
3. EARLY STUDIES OF THE IBM ARC SYSTEM......Page 180
4. HISTORY OF THE IBM ARC SYSTEM......Page 184
5. INPUTS INTO THE SUBDUCTION FACTORY......Page 186
6. GEOPHYSICS OF THE SUBDUCTED SLAB AND MANTLE......Page 189
7. IBM SUBDUCTION FACTORY OUTPUT......Page 195
8. CONCLUSIONS......Page 217
REFERENCES......Page 218
Along-Strike Variation in the Aleutian Island Arc: Genesis of High Mg# Andesiteand Implications for Continental Crust......Page 227
1. INTRODUCTION......Page 228
2. ALONG-STRIKE VARIATION IN LAVACOMPOSITION......Page 243
4. GENESIS OF WESTERN ALEUTIAN HIGH MG# ANDESITES......Page 254
5. IMPLICATIONS FOR CONTINENTAL GENESIS......Page 270
6. CONCLUSIONS......Page 271
REFERENCES......Page 272
INTRODUCTION......Page 281
SPATIAL DISTRIBUTION OF ARC VOLCANOES......Page 282
LAVA CHEMISTRY......Page 287
THERMAL STRUCTURE......Page 290
REFERENCES......Page 293
1. INTRODUCTION......Page 297
2. PRESSURE AND TEMPERATURE IN THESHALLOW MANTLE AND LOWERCRUST BENEATH ARCS......Page 300
3. Seismic Constraints on Melt Distribution in theUppermost Mantle......Page 302
4. RAPID ADVECTION IN THE MANTLE WEDGE......Page 303
6. CAVEATS......Page 310
REFERENCES......Page 311