Contourites

Volume Editors......Page 2
Copyright Page......Page 3
Preface......Page 4
List of Contributors......Page 6
sdarticle_004.pdf......Page 10
Contourite Research: A Field in Full Development......Page 11
Bottom Currents......Page 12
Contourites......Page 14
Drifts......Page 16
Sedimentary Structures......Page 17
Prospects......Page 18
Introduction......Page 19
Not All Deep-Sea Sands are Turbidites......Page 20
Turbidophiles and Turbidophobes......Page 22
Erosional Unconformity Misinterpreted......Page 23
Introduction......Page 26
Oceanographic Measurements......Page 27
Geophysical Methods......Page 28
Sampling Strategies......Page 34
Analytical Methods......Page 36
Summary of Multidisciplinary Techniques......Page 38
Acknowledgements......Page 40
sdarticle_007.pdf......Page 41
Introduction......Page 42
Abyssal Currents in the Global Thermohaline Circulation......Page 45
Physical properties and modes......Page 47
Entrainment and modeled contour currents......Page 56
Conclusion and Summary......Page 60
Acknowledgments......Page 62
Introduction......Page 63
Bottom currents versus turbidity currents......Page 64
Genetic nomenclature......Page 66
Velocity......Page 67
Deposits......Page 68
Reservoir potential......Page 70
Velocity......Page 71
Deposits......Page 72
Reservoir potential......Page 74
Velocity......Page 76
Deposits......Page 79
Reservoir potential......Page 80
Nomenclature......Page 81
Velocity......Page 83
Deposits......Page 84
Acknowledgments......Page 85
Introduction......Page 86
Spectral Windows......Page 88
General characteristics......Page 90
Interactions with the sea floor and suspended particles......Page 91
The Ekman layer......Page 92
The Ekman solution......Page 93
Thickness of the Ekman boundary layer......Page 96
The viscous sub-layer (bed layer)......Page 97
The logarithmic layer......Page 98
Conclusions......Page 99
Acknowledgements......Page 100
sdarticle_010.pdf......Page 101
Introduction......Page 102
Benthic Storms (Transportation and Resuspension of Particles)......Page 103
Gravity Flows......Page 106
Turbidity currents......Page 107
Debris flows......Page 112
Hyperpycnal flows......Page 114
Bioclastics-Forming Processes in Contourites......Page 116
Volcaniclastics......Page 117
Glacial Activity......Page 118
Acknowledgements......Page 119
Introduction......Page 121
Measurement of fine grain sizes......Page 123
Size distributions of components......Page 125
Unsorted Delivery to Deep Current Systems: Pelagic Flux and Down-Slope Transport......Page 126
Settling velocity of grains and aggregates, ws......Page 127
Boundary-layer flow structure and turbulence......Page 130
Sorting in Suspension Transport......Page 131
Limiting shear stress for deposition taud......Page 132
Sorting by selective deposition: cohesive versus sortable silt......Page 134
Repeated sorting events under deep-sea storm conditions......Page 135
Spatial variability of sediment size over bedforms and drifts......Page 137
Gardar Drift and Bermuda Rise at the penultimate glacial termination......Page 140
Flow on the Iberian Margin over the last glacial cycle......Page 141
Acknowledgements......Page 142
sdarticle_013.pdf......Page 143
Introduction......Page 144
The Traction-Structures Controversy......Page 145
Setting the Stage for Sedimentary Structures in Contourites......Page 146
Current ripples and cross-lamination......Page 147
Lenticular and flaser bedding......Page 155
Horizontal, subhorizontal, and sinusoidal lamination......Page 156
Large-scale cross-bedding......Page 157
Erosional structures......Page 159
Grading......Page 160
Less common structures......Page 161
The Faro Drift facies model......Page 162
The Gulf of Mexico facies model......Page 164
Conclusions......Page 166
Acknowledgments......Page 167
Introduction......Page 168
Bottom-Current Characteristics......Page 169
Sedimentation rates and budget......Page 171
Drift Deposition and Erosion......Page 172
Bottom-Current Bedforms......Page 174
Sedimentary structures......Page 176
Sedimentary texture and fabric......Page 177
Contourite composition......Page 178
Contourite Cyclicity......Page 179
Acknowledgements......Page 180
hairspIntroduction......Page 182
Biota......Page 184
Burrowing activity in current-affected settings......Page 185
Bioturbation, trace fossils and ichnofabrics......Page 186
Hiatuses......Page 188
Gulf of Cadiz......Page 189
Nova Scotia Rise......Page 191
Faeroe-Shetland Channel......Page 192
Strong currents: non-deposition horizons and sand-dominated contourites......Page 195
Weak currents - mud-dominated contourites......Page 197
Perspective......Page 200
Acknowledgements......Page 201
Introduction......Page 202
Some Examples of Sedimentary Rhythms Associated with Changes in Colour......Page 203
Diagenesis of Fine-Grained Contourites......Page 206
Manganese oxidation processes......Page 207
Iron oxidation processes......Page 209
Diagenesis of Coarse-Grained Contourites......Page 211
Glauconite growth......Page 212
Acknowledgements......Page 220
Contourite Facies and the Facies Model......Page 221
Historical Context......Page 222
The Range of Contourite Facies......Page 223
Silty contourites......Page 224
Sandy contourites......Page 226
Shale-clast or shale-chip layers......Page 228
Calcareous muddy and silty contourites......Page 229
Calcareous sandy contourites......Page 230
Siliceous bioclastic contourites......Page 231
Contourite Facies Model and the Contourite Sequence......Page 232
Sequence origin and interpretation......Page 235
Lamination Versus Bioturbation in Contourites......Page 236
Mixed turbidite/contourite systems......Page 237
Contourite-Related Facies......Page 238
Acknowledgements......Page 248
Norwegian Continental Margin......Page 249
Gulf of Cadiz, Iberian Margin......Page 250
East South American Continental Margin......Page 251
East New Zealand Continental Margin, SW Pacific......Page 252
Antarctic Continental Margin and Weddell Sea......Page 253
sdarticle_017.pdf......Page 255
Contourite Drifts: Nature, Evolution and Controls......Page 256
Introduction......Page 257
Drift size......Page 259
Bottom-current type......Page 260
The first sedimentary unit......Page 261
The third unit......Page 264
Current conditions......Page 265
Sea level......Page 266
Climate change......Page 267
Contourite-Drift Types......Page 268
Mounded drifts......Page 269
Mixed drift systems......Page 278
Spatial evolution of drifts......Page 280
Evolution of drifts in time......Page 281
Distinction from turbidite systems......Page 282
Buried contourite drifts in modern ocean successions......Page 283
Acknowledgements......Page 285
Introduction......Page 286
Location, Morphology and Genesis of Fine-Grained Sediment Waves......Page 287
Location, Morphology and Genesis of Coarse-Grained Sediment Waves......Page 291
Related Large-Scale Features Generated by Bottom Currents......Page 293
Applications to Bottom-Current Reconstruction: A Case Study From the NW UK......Page 295
Acknowledgements......Page 297
Introduction......Page 298
Large scale – first-order seismic elements......Page 299
Medium scale – second-order seismic elements......Page 301
Seismic scale......Page 302
Reflection-seismic methods......Page 305
Seismic mapping......Page 311
Seismic interpretation......Page 312
Summary......Page 317
Acknowledgements......Page 318
hairspIntroduction......Page 319
Neogene contourites, Miura-Boso region, SE Japan......Page 320
Palaeoceanography......Page 321
Carbonate contourite drift, Oligocene palaeoslope, Cyprus......Page 322
Palaeoceanography......Page 324
Carbonate contourite drifts, Late Cretaceous-Palaeocene Chalk Group, Danish Basin......Page 325
Carbonate contourites, Devonian pelagic successions, Europe and North Africa......Page 328
Palaeocirculation......Page 332
Carbonate contourites, Ordovician Jiuxi Drift, China......Page 334
Palaeocirculation......Page 335
Recognition of ancient contourites......Page 336
Sea level and preservation of contourite drifts......Page 339
Acknowledgements......Page 340
sdarticle_021.pdf......Page 341
Introduction......Page 342
Terminology......Page 345
Southern hemisphere basins......Page 346
Equatorial abyssal plains......Page 354
Oceanic Gateways......Page 359
Nepheloid layer......Page 360
Benthic storms......Page 362
Effect of sea-floor obstacles......Page 364
Large-scale depositional and erosional features......Page 365
Sedimentary facies......Page 369
Final Considerations......Page 370
Acknowledgements......Page 373
Introduction......Page 374
Upper slope......Page 377
Middle slope......Page 381
Lower slope......Page 387
Lower Slope to Continental Rise Transition and Other Kinds of Slopes......Page 390
Large-scale depositional features......Page 391
Large-scale erosional features......Page 392
Facies characteristics......Page 394
Final Considerations......Page 400
Acknowledgements......Page 402
Introduction......Page 404
Bottom Currents Shaping Shallow-Water Contourite Deposits......Page 407
Cascading currents......Page 408
Wind-driven currents......Page 409
Outer shelf of the SE-African continental margin......Page 410
Antarctica shelves......Page 411
Campos Basin outer-shelf/upper-slope contourite system (offshore SE Brazil)......Page 413
Gulf of Cadiz outer-shelf/upper-slope contourite system......Page 415
Mediterranean shallow-water contourite deposits......Page 418
Shallow contourite deposits within sills, gateways and slope basins......Page 422
Discussion......Page 425
Slope stability of shallow-water contourite deposits......Page 426
Summary......Page 427
Acknowledgements......Page 428
Introduction......Page 429
Low-frequency alternation: morphological heritage......Page 430
High-frequency alternations of contourites and turbidites......Page 432
Redistribution of Gravity Deposits by Contour Currents......Page 436
Interaction of Synchronous Contour and Turbidity Currents......Page 440
Conclusions......Page 448
Acknowledgements......Page 450
thinspIntroduction......Page 451
Northern North Atlantic......Page 452
Southern Ocean......Page 454
Rockall Trough and glacial record off Northwest Britain......Page 455
Seismic characteristics......Page 458
Sedimentary characteristics......Page 461
The West Shetland Drift......Page 465
Norwegian continental margin......Page 467
Greenland Margin......Page 469
Cooperation Sea......Page 471
Cosmonaut Sea and Riisen-Larsen Sea......Page 474
Antarctic Peninsula Pacific Margin......Page 476
Conclusions......Page 482
Acknowledgements......Page 483
sdarticle_026.pdf......Page 484
Introduction......Page 485
Major Implications of Contourite Studies......Page 486
Contourites and Petroleum Exploration......Page 488
Coarse-grained contourites: reservoirs......Page 490
The impact of sea-floor topography......Page 491
Seismic and well-log characteristics of contourites......Page 495
Fine-grained contourites: sealing and source rocks......Page 496
Processes and main depositional elements......Page 498
Trends of future contourite studies motivated by economic significance......Page 501
Acknowledgements......Page 502
Introduction......Page 503
Oceanographic Settings of Contourites......Page 504
Palaeoceanographic tracers......Page 507
Non-destructive techniques......Page 512
Seismic imaging......Page 513
Gateways, tectonics, and ocean circulation......Page 516
Ocean circulation during warm climate extremes......Page 520
Rapid ocean-climate variability in the North Atlantic......Page 521
Summary......Page 526
Acknowledgements......Page 527
Introduction and Objective......Page 528
Background......Page 529
Northern mid- and high-latitude contourites and submarine landslides......Page 530
Southern mid- and high-latitude contourites and submarine slope instability......Page 536
Recapitulation of evidence......Page 541
Gravitational instability of submarine slopes......Page 543
Characteristics of contourites that favour slope instability......Page 545
Summary......Page 546
Acknowledgements......Page 547
Color Plates......Page 548