Diversity of Hydrothermal Systems on Slow Spreading Ocean Ridges

Title Page
......Page 3
Copyright
......Page 4
Contents
......Page 5
Preface
......Page 7
Diversity of Hydrothermal Systems on Slow Spreading Ocean Ridges: Introduction......Page 8
REFERENCES......Page 9
1. EARLY RIFTING......Page 11
4. EAST PACIFIC RISE......Page 12
5. MID-ATLANTIC RIDGE......Page 13
REFERENCES......Page 14
1. Introduction......Page 17
2. Observational Constraints and Modeling Parameters......Page 18
3. Hydrothermal Heat Sources and Heat Transfer Processes......Page 19
4. Conclusions......Page 28
References......Page 29
2. VENT SITES......Page 33
4. DISCUSSION......Page 40
REFERENCES......Page 45
1. Introduction......Page 49
2.1. TAG Hydrothermal Field ㈀㘀뀀　㠠㈀一 㐀㐀뀀㐀㔠㈀圀......Page 51
2.3. Lucky Strike ㌀㜀뀀㄀㜠㈀一 ㌀㈀뀀㄀㜠㈀圀......Page 58
2.5. South Atlantic Vent Sites......Page 61
2.6. Ultramafic-Hosted Vent Deposits......Page 62
3. Conclusions......Page 66
References......Page 67
1. Introduction......Page 73
2. Arctic Mid-Ocean Ridges......Page 74
3.1. Grimsey Hydrothermal Field......Page 75
4.1. Jan Mayen Vent Fields at 71°N......Page 77
4.3. Massive Sulfide Deposits at 73°N......Page 80
4.4. Lokeslottet the Loki’s Castle Vent Field......Page 82
5.1. Seawater Anomalies at 75°N......Page 84
7.1. Volcanic and Tectonic Control of Vent Fieldsat the AMOR......Page 85
7.2. Diversity of Hydrothermal Fluids and Deposits......Page 88
7.3. Peridotite-Hosted Systems and the Potential for NovelHydrothermal Systems......Page 90
7.5. Magmatic Starvation and Hydrothermal Activity......Page 91
References......Page 92
1.1. The Geological Setting of Iceland......Page 96
1.2. Hydrothermal Systems in Iceland......Page 98
1.3. The Iceland Deep Drilling Project......Page 99
1.4. Supercritical Conditions......Page 100
2. Evolution of the IDDP......Page 101
2.1. Predicting Permeability......Page 103
2.2. First Attempt at Reykjanes......Page 107
2.3. A Deep Hole at Krafla......Page 108
2.4. IDDP-1 Encounters Rhyolitic Magma......Page 111
3. Relevance to Mid -Ocean Rift Hydrothermal Systems......Page 112
4. Summary and Conclusions......Page 113
References......Page 114
1. Introduction......Page 118
2. Geodynamic Contextand Previous Studies......Page 119
3. The Sismomar Experiment......Page 121
4. Results......Page 123
5. Comparison With Other High-T,Basalt -Hosted Fields......Page 128
6. Discussion......Page 133
References......Page 134
1. Introduction......Page 138
2. Tectonics and Volcanolog y of the Southern Equatorial Mid-Atlantic Ridge......Page 139
3. Recently Discovered Hydrothermal Sites......Page 141
4. Regional Hydrothermal Prospection......Page 143
5. Why are Hydrothermal Systems Where They are?......Page 148
6. A Model......Page 152
7. Predictions......Page 153
8. Conclusions......Page 154
References......Page 156
1. INTRODUCTION......Page 158
3. EVOLUTION OF THE SOUTHWEST INDIAN RIDGE......Page 161
4. LARGE-SCALE VARIATIO NS OF MELT SUPPL YALONG THE SWIR......Page 162
5. FOCUSED MAGMATISM VERSUS NONVOLCANIC SPREADING SEGMENTS ALONG THE SWIR AXIS......Page 166
6. A 26-MYR-LONG RECORD OF AXIAL TECTO NICAND MAGMATIC PROCESSES IN THE EASTERNMOST Melt Poor Section of the SWIR......Page 169
7. MECHANISMS FOR ALONG-AXIS MELT FOCUSING AND REDISTRIBUTION......Page 171
8. OUTSTA NDING QUESTIONS......Page 173
REFERENCES......Page 174
1. Introduction......Page 179
2.1. Continental Settings......Page 182
2.2. Oceanic Settings......Page 189
3. Discussion......Page 202
4. Conclusions......Page 203
References......Page 204
Detachment Fault Control on Hydrothermal Circulation Systems:Interpreting the Subsurface Beneath the TAG HydrothermalField Using the Isotopic and Geological Evolutionof Oceanic Core Complexes in the Atlantic......Page 210
1. Introduction......Page 211
2. Geological and Tectonic Settingof Oceanic Core Complexes......Page 212
3. Off-Axis High-Temperature Vent Fieldsin the Atlantic......Page 213
4. Conditions of Hydrothermal Alterationand Deformation Within and BelowDetachment Faults at 30°N and 15°45′N......Page 216
5. Methods......Page 218
6. Isotope Data and Chemical Alteration......Page 219
7. Discussion......Page 226
8. Conclusions......Page 236
References......Page 237
1. Introduction......Page 243
2.1. Extension of Domains With Frequent UltramaficOutcrops in Slow and Ultraslow Spreading Oceanic Crust......Page 245
2.2. Proportions of Magmatic Rocks in the Crustof Domains With Frequent Ultramafic Outcrops......Page 246
2.3. Proportion of Mantle-Derived Ultramaficsin Slow and Ultraslow Spreading Oceanic Crust......Page 248
3. What is the Degree of Serpentinization in the Crust of Domains With Frequent Ultramafic Outcrops?......Page 249
4. Estimating Hydrogen and Methane Fluxes Associated With Serpentinization......Page 250
4.1. Estimating Hydrogen Fluxes per Kilometer of RidgeAxis From the Proportion of Serpentine in SlowSpreading Crust......Page 251
4.2. Estimating Hydrogen and Methane FluxesFrom Regional Hydrothermal Heat Loss......Page 253
4.3. Hydrogen and Methane Fluxes at the Ultramafic-Hosted Rainbow Hydrothermal Vent Field:How Do They Fit With Estimated Hydrogen Fluxesper Kilometer of Ridge Axis?......Page 256
5. Discussion......Page 257
6. Conclusions......Page 260
References......Page 261
1. Introduction......Page 267
2.2. Lost City Hydrothermal Field......Page 271
2.4. Ashadze Area: Ashadze I and II Active Vent Fields......Page 272
3. Sampling and Analytical Methods......Page 273
4. Results......Page 278
5.1. Phase Separation and Stability of Ultramafic Vents......Page 279
5.2. High Hydrogen Production in UltramaficHydrothermal Systems......Page 285
5.4. Abiotic Synthesis and Occurrence of Organicsin Hydrothermal Fluids: A Potential Consequenceof H2 Production Along the Mid-Atlantic Ridge......Page 287
5.6. Hydrogen: A Sustainable Natural Energy SourceFrom the Mantle?......Page 288
6. Conclusions......Page 290
References......Page 291
1. INTRODUCTION......Page 299
2. THEORETICAL AND EXPERIMENTAL APPROACH......Page 302
3. RESULTS : REACTIONS IN THE MODEL SYSTEM......Page 307
4. DISCUSSION......Page 311
5. CONCLUSIONS......Page 317
REFERENCES......Page 318
1. Introduction......Page 323
2. Occurrences of Ultramafic Rocks AlongSlow Spreading Ridges......Page 324
3. Hydrothermal MineralizationAssociated with Ultramafic RocksAlong the MAR......Page 330
4. Morpholog y of Ultramafic -HostedHydrothermal Deposits......Page 334
5. Fluid Compositions in UltramaficEnvironments......Page 336
6. Mineralog y of Ultramafic -HostedHydrothermal Deposits......Page 342
7. Chemical Composition of Deposits......Page 343
8. Discussion......Page 354
9. Summary and Conclusions......Page 359
References......Page 360
1. A DECADE OF DISCOVERIES......Page 370
2. HYDROTHERMAL SYSTEMS HOSTED BY DIVERSE ROCK TYPES......Page 373
2.1. Type 1: Magmatically Dominated Systems?Lucky Strike and 5°S......Page 375
2.2. Type II: Ultramafic and Gabbroic-Hosted Hydrothermal Systems?Logatchev Hydrothermal Field......Page 384
2.3. Type III: Ultramafic-Dominated Systems?The Lost City Hydrothermal Field......Page 385
3. SERPENTINIZATION AND ABIOGENIC ORGANIC SYNTHESIS......Page 386
3.1. Abiogenic Synthesis......Page 387
3.2. Carbon in the Crust......Page 388
4. DETACHMENT FAULTS AND SIGNIFICANCE TO HYDROTHERMAL FLOW......Page 390
4.1. Hydrothermal Flow in Young Detachment Systems:TAG......Page 391
5.1. Turtle Pits and Comfortless Cove Field......Page 392
5.2. Phase Separation in the Crust......Page 393
6. MAGMA CHAMBERS, HARMONIC TREMOR,AND ERUPTIONS......Page 394
7. PATTERNS OF BIOLOGICAL DIVERSITY IN SLOW SPREADING RIDGES......Page 395
8. FUTURE RESEARCH......Page 398
REFERENCES......Page 400
1. Introduction......Page 409
2. Overview of Bacterial Symbiosis in MAR Mussels and Link with End-Member Fluid Compositions......Page 413
3. Chemical Chara cteristics of Mussel Microhabitats and Potential Influence on Symbiont Abundances......Page 416
4. Access to Ch emical Energy Resources......Page 421
5. Th e Plasticity of Symbioses: A Key to the Colonization of Contrasted Environment by B. Azoricus?......Page 424
6. Conclusion: A Natural Laboratory for the Study of Interactions Between Biogeochemical Processes and the Functioning of Bathymodiolus Dual Symbiosis......Page 425
References......Page 426
Index......Page 430