The Subseafloor Biosphere at Mid-Ocean Ridges

The Subseafloor Biosphere at Mid-Ocean Ridges......Page 3
Copyright......Page 4
CONTENTS......Page 5
PREFACE......Page 7
1. INTRODUCTION......Page 8
2.1. Life in the Subsurface......Page 9
2.2. Life in Mid-Ocean Ridge Hydrothermal Systems......Page 10
3.1. What are the Patterns of Hydrothermal Circulation?......Page 11
3.3. What Organisms are Active in the Seafloor and What do They Do?......Page 12
3.5. What can we Learn from Comparisons with Other Subsurface Environments?......Page 14
REFERENCES......Page 15
1. INTRODUCTION......Page 19
2.3. Phylogeny......Page 20
3.1. Hyperthermophile Culture Studies......Page 21
3.3. Effect of Pressure......Page 22
3.4. Laboratory Studies on Natural Microbial Assemblages......Page 23
3.5. Field Observations......Page 24
4. TEMPERATURE AND THE SUBSEAFLOOR BIOSPHERE......Page 26
REFERENCES......Page 27
1. INTRODUCTION......Page 31
2.1.NADP......Page 32
2.2. ATP, ADP, AMP and PP......Page 33
2.4. General Mechanisms......Page 34
3.1. Denaturation......Page 35
3.3. Extrinsic Factors......Page 36
4.1. DNA Structure......Page 37
4.2. RNA Structure......Page 38
5. LIPIDS AND MEMBRANES......Page 39
REFERENCES......Page 41
INTRODUCTION......Page 46
LIMITS TO LIFE FOR METAZOANS......Page 47
Nutritional Limits for Metazoans......Page 48
CASE STUDIES OF ANIMALS LIVING IN EXTREME HABITATS......Page 49
Survival at Low Oxygen......Page 50
High Temperature Tolerance......Page 51
REFERENCES......Page 52
1. INTRODUCTION......Page 55
2. HYDROLOGICAL CONCEPTS......Page 56
3. GLOBAL CONSTRAINTS ON THE PHYSICAL PROPERTIES OF OCEANIC CRUST......Page 60
4. CONSTRAINTS ON HYDROTHERMAL CIRCULATION AT SPREADING CENTERS......Page 63
5.1. East Pacific Rise Near 9°50'N......Page 64
5.2. Endeavour Ridge......Page 67
5.3. TAG Site......Page 71
6. FUTURE DIRECTIONS......Page 73
REFERENCES......Page 74
INTRODUCTION AND BACKGROUND......Page 79
OCEAN CRUSTAL STRUCTURE......Page 80
PHYSICAL PROPERTIES OF THE UPPER OCEAN CRUST......Page 82
AXIAL PROCESSES......Page 83
MECHANICS OF DIKING......Page 84
DIRECT OBSERVATIONS OF MID-OCEAN RIDGE DIKE INJECTION AND ERUPTIONS......Page 86
EVENT PLUMES......Page 90
MECHANISM OF EVENT PLUME GENERATION......Page 92
SOME INFERENCES ABOUT THE SUBSURFACE BIOSPHERE IN THE OCEANIC CRUST......Page 94
REFERENCES......Page 96
Fluid Flow and Fluid-Rock Interaction Within Ocean Crust: Reconciling Geochemical, Geological, and Geophysical Observations......Page 102
LOWER CRUST AND UPPER MANTLE......Page 103
Atlantis Bank......Page 104
The MARK Area......Page 105
UPPER AND MIDDLE CRUSTAL SECTION......Page 106
RIDGE FLANK HYDROTHERMAL SYSTEMS......Page 107
Holes 504B and 896A......Page 108
Hole 395A......Page 110
Other Drill Holes......Page 111
Rates and Distribution Characteristics of Ridge Flank Circulation......Page 112
SUMMARY......Page 113
REFERENCES......Page 115
Serpentinization of Oceanic Peridotites: Implications for Geochemical Cycles and Biological Activity......Page 121
1. INTRODUCTION......Page 122
2.1. Mineralogical and Chemical Consequences......Page 123
2.2. Temperatures of Serpentinization......Page 126
3.2. C-O-H-S Fluid Speciation as a Function ofXQ......Page 127
3.3. Ultramafic Model Systems......Page 128
4. METHANE-RICH FLUIDS IN PERIDOTITE-HOSTED HYDROTHERMAL SYSTEMS......Page 131
5. IMPLICATIONS FOR CARBON CYCLES AND BIOLOGICAL ACTIVITY......Page 132
REFERENCES......Page 134
1. INTRODUCTION......Page 139
2.1. Calculating Pressure Difference and Velocity......Page 141
2.3. Calculating Fluid Composition X Within Pores......Page 142
3.1. Temperature Profiles......Page 143
3.2. Concentration Profiles......Page 144
3.3. Metabolic Energy......Page 148
4. DISCUSSION......Page 149
4.2. Energy Available Within Vent Structures......Page 151
REFERENCES......Page 152
GEOCHEMICAL MODELING OF BIOAVAILIABLE ENERGY......Page 155
Modeling Ridge-Crest Systems......Page 157
Testing Geochemical Models of Metabolism at the Ridge Crest......Page 158
The Impact of Hydrogen Oxidation on Geochemical Bioenergetics of Ridge-Crest Systems......Page 160
A Word Concerning Heterotrophs......Page 163
FUTURE DIRECTIONS: MODELS FOR OTHER SUBSURFACE ENVIRONMENTS......Page 164
REFERENCES......Page 165
1. INTRODUCTION......Page 168
2. MID-OCEAN RIDGE MAGMA CHAMBERS: VOLATILES AT DEPTH......Page 170
3. MORB'S: WINDOWS INTO MANTLE AND MAGMA CHAMBER GASES......Page 171
3.2. Volatiles in the Shallow Crust......Page 172
3.4. Fluids in Fossilized Magma Chambers......Page 173
4.1. Volatiles in Megaplumes......Page 176
4.2. Stable Hydrothermal Systems......Page 179
4.3. Neutral Hydrothermal Plumes......Page 180
4.4. Mantle-Hosted Hydrothermal Systems......Page 181
REFERENCES......Page 183
1.1. Thermodynamics and Kinetic Catalysis......Page 191
1.2. Electron Acceptor and Donor Properties of Small Molecules......Page 192
2. TRANSITION METAL CATALYSIS......Page 193
2.2. An Example of Organic Synthesis Using Metal Catalysts......Page 194
2.4. Examples of Metal Catalysis in Biotic Processes......Page 196
REFERENCES......Page 197
INTRODUCTION......Page 199
OXIDATION OF ACETATE COUPLED TO FEIII REDUCTION......Page 201
NEW MODEL FOR OXIDATION OF ORGANIC MATTER IN HOT ENVIRONMENTS......Page 204
REDUCTION OF HUMICS AND OTHER EXTRACELLULAR QUINONES......Page 205
REDUCTION OF TOXIC, RADIOACTIVE AND PRECIOUS METALS......Page 206
CULTURING PREVIOUSLY UNCULTURABLE ORGANISMS WITH FEIII......Page 207
FUTURE DIRECTIONS......Page 208
REFERENCES......Page 209
INTRODUCTION......Page 212
METABOLISM OF HYPERTHERMOPHILIC MICROORGANISMS......Page 213
COMPLEX CARBOHYDRATE UTILIZATION BY HYPERTHERMOPHILES......Page 215
EXOPOLYSACCHARIDE PRODUCTION AND BIOFILM FORMATION IN HYPERTHERMOPHILES......Page 216
DEEP-SEA MESOPHILIC POLYSACCHARIDES......Page 218
MIXED CULTURES AND IMPLICATIONS ON NATURAL MICROBIAL COMMUNITIES......Page 219
REFERENCES......Page 220
Detection of and Response to Mid-Ocean Ridge Magmatic Events: Implications for the Subsurface Biosphere......Page 226
Pre- and Non-SOSUS......Page 227
SOSUS System......Page 229
SOSUS Directed Event Responses......Page 230
Pre-event Staging......Page 232
Recent Event Responses......Page 234
Window to the Subseafloor......Page 235
Event Plume Physical and Biogeochemical Dynamics......Page 236
CONCLUSIONS......Page 237
REFERENCES......Page 238
1. INTRODUCTION......Page 243
2. SAMPLE COLLECTION......Page 246
4. SAMPLING SITES......Page 250
4.1. Northern Transect......Page 251
5. RESULTS AND DISCUSSION......Page 254
5.1. Northern Transect......Page 255
5.2. Middle Transect......Page 258
5.3. Southern Transect......Page 259
5.4. Summary and Comparison of the Three Areas......Page 262
6. SUMMARY AND CONCLUSIONS......Page 263
REFERENCES......Page 265
Mixing, Reaction and Microbial Activity in the Sub-seafloor Revealed by Temporal and Spatial Variation in Diffuse Flow Vents at Axial Volcano......Page 267
2. METHODS......Page 268
3.1. Location of Venting in the SE Caldera of Axial Volcano......Page 269
3.3. High-Temperature Fluid Composition and Mixing......Page 273
3.4. Conductive Heat Exchange......Page 278
3.5. Microbiological Data......Page 279
3.6. Geochemical Constraints on Microbial Productivity Below the Seafloor......Page 281
4. CONCLUSIONS......Page 284
REFERENCES......Page 285
MICROBIOLOGY AS A GEOLOGICAL TOOL......Page 288
APPLICATION OF MICROBIAL TRACERS TO THE SUBSEAFLOOR......Page 289
MICROBIAL EVIDENCE FOR RIDGE-ASSOCIATED SUBSEAFLOOR ECOSYSTEMS......Page 291
MICROBIAL EVIDENCE FOR NOVEL CRUSTAL HABITATS AT RIDGE CRESTS......Page 295
THE SUBSEAFLOOR ENVIRONMENT AS SEEN THROUGH A MICROBE......Page 298
REFERENCES......Page 299
1. INTRODUCTION......Page 301
2. STUDYING THE SUBSURFACE ENVIRONMENT AT SEDIMENTED RIDGES......Page 302
3. GEOLOGIC SETTING OF SEDIMENTED RIDGES......Page 303
4. CHEMICAL SETTING OF SEDIMENTED RIDGES......Page 306
5. SUBSURFACE LIFE AT SEDIMENTED RIDGES......Page 312
6. THE RED SEA: A UNIQUE OPPORTUNITY......Page 314
REFERENCES......Page 315
The Oceanic Crust as a Bioreactor......Page 320
2. PROBLEMS IN STUDYING THE DOB......Page 321
3. FORENSIC MICROBIOLOGY IN THE OCEANIC CRUST......Page 322
6. EXPERIMENTAL STUDIES......Page 324
7. DISCUSSION......Page 333
8. CONCLUSION......Page 334
REFERENCES......Page 335
Diversity of Life at the Geothermal Subsurface?Surface Interface: The Yellowstone Example Geophysical Monograph Series......Page 337
2. PHYLOGENETIC PERSPECTIVE AND MICROBIAL ECOLOGY......Page 338
3. BACTERIA IN YELLOWSTONE HOTSPRINGS......Page 340
4. ARCHAEA IN YELLOWSTONE HOTSPRINGS......Page 342
6. METABOLIC BASIS OF THE YELLOWSTONE HIGH-TEMPERATURE ECOSYSTEM......Page 344
9. CONCLUSION......Page 346
REFERENCES......Page 347
INTRODUCTION......Page 349
MICROBIAL 'DEAD' ZONES IN THE SUBSURFACE......Page 350
MICROBIAL OASES IN THE SUBSURFACE......Page 355
CONSIDERATIONS FOR FUTURE INVESTIGATIONS......Page 356
REFERENCES......Page 358
1. INTRODUCTION......Page 362
2. ARCHAEAL COMMUNITIES IN DEEPSUBSURFACEHIGH- TEMPERATURE HABITATS......Page 363
3. ARCHAEA IN SUBVENT BIOSPHERES......Page 365
4. THE LOW-TEMPERATURE SUBSEAFLOOR BIOSPHERE......Page 368
REFERENCES......Page 372
INTRODUCTION......Page 375
TOOLS AVAILABLE TO STUDY THE DEEP SUBSURFACE: COMPOSITION......Page 377
GENOMIC APPROACHES FOR CHARACTERIZING SUBSURFACE MICROBIAL COMMUNITIES......Page 382
INDUSTRIAL APPLICATIONS OF DEEP SUBSURFACE METABOLIC DIVERSITY......Page 385
REFERENCES......Page 386