The Mesozoic Pacific: Geology, Tectonics, and Volcanism

The Mesozoic Pacific: Geology, Tectonics, and Volcanism......Page 1
Geophysical Monograph Series......Page 2
The Mesozoic Pacific: Geology, Tectonics, and Volcanism......Page 6
CONTENTS......Page 7
Tectonic History of the Late Cretaceous Pacific......Page 9
Suggestions for Future Work......Page 10
Shallow-water carbonate dia genesis and sea level......Page 12
Mid-plate flood basalts......Page 13
REFERENCES......Page 14
INTRODUCTION......Page 16
TECHNIQUES......Page 17
INTEGRATED APTIAN-ALBIAN MICROFOSSIL BIOCHRONOLOGY......Page 19
STRATIGRAPHIC AND GEOGRAPHIC DISTRIBUTION OF ORGANIC CARBON-RICH INTERVALS......Page 23
CHANGES OF PLANKTON ASSEMBLAGES......Page 39
PLANKTON EVOLUTION AND DYSOXIA/ANOXIA......Page 40
CAUSES OF "OCEANIC ANOXIC SURE VENTS"......Page 42
REFERENCES......Page 44
INTRODUCTION......Page 49
TILE OLD SEA FLOOR DOES NOT "FLATTEN"......Page 50
THE COOLING HALFSPACE REFERENCE......Page 51
RESIDUAL DEPTH ANOMALIES IN THE PACIFIC......Page 52
RELATED PROPOSALS......Page 53
Thinned Lithosphere......Page 54
OTHER GEOPHYSICAL EVIDENCE......Page 55
TOPOGRAPHY FROM DEEP, WARM MANTLE......Page 56
PERSISTENCE OF SWELLS AND SUPERS WELLS......Page 57
ORIGIN AND PERSISTENCE OF THE DARWIN RISE: SUMMARY......Page 58
Other Effects of Superswells......Page 60
REFERENCES......Page 61
INTRODUCTION......Page 63
Motivation......Page 66
PROPERTIES OF REFERENCE MODELS......Page 69
Ocean-specific Data......Page 71
Geoid Data......Page 72
COMPARISON OF TEMPERATURE MODELS......Page 73
Asymptotic Depth and Heat Flow......Page 74
HOT SPOT SWELLS......Page 75
DARWIN RISE DEPTH AND HEAT FLOW......Page 77
SUPERSWELL DEPTH AND HEAT FLOW......Page 78
FLEXURAL DATA......Page 80
CONCLUSIONS......Page 83
REFERENCES......Page 84
INTRODUCITON......Page 87
Western Pacific Seismic Stratigraphy......Page 89
Leg 129 Site Review......Page 90
DATA ACQUISITION AND PROCESSING......Page 92
SEISMIC OBSERVATIONS AND RESULTS......Page 95
General Characterization of Horizon B......Page 98
Horizon B in The East Mariana Basin......Page 99
Horizon B in The Pigafetta Basin......Page 101
Sill/Flow/Sediment Thickness......Page 103
DISCUSSION......Page 107
Magnetic Rough-Smooth Boundary......Page 108
CONCLUSIONS......Page 109
REFERENCES......Page 110
INTRODUCTION......Page 112
Basement to Cretaceous Volcanics......Page 114
Post Late Cretaceous Sediments......Page 119
DISCUSSION......Page 123
REFERENCES......Page 127
INTRODUCTION......Page 129
Nosappu Fracture Zone......Page 131
Central Pacific Fracture Zone......Page 134
Kashima Fracture Zone......Page 136
Nosappu Fracture Zone......Page 137
South Shatsky Fracture Zone......Page 138
Phoenix Fracture Zone......Page 139
THE VERTICAL DISPLACEMENT ALONG A FRACTURE ZONE......Page 141
SUMMARY AND CONCLUSIONS......Page 142
REFERENCES......Page 143
INTRODUCTION......Page 145
GEOSAT Altimetry......Page 148
Fracture zone compilation......Page 152
REVISED MESOZOIC TECTONIC CHART......Page 153
Molokai Fracture Zone......Page 154
Development of the Kula Plate and Chinook Plate?......Page 155
Variations in fracture zone widths......Page 156
CONCLUSIONS......Page 159
REFERENCES......Page 161
INTRODUCTION......Page 163
Methods......Page 164
General Results......Page 165
Structural Pattern of the Molokai Fracture Zone......Page 166
Correlation of Fracture-zone Strands across the Hawaiian Ridge......Page 170
Time of the Change in Spreading Drection......Page 171
Lateral Offsets along the Molokai Fracture Zone......Page 172
Response of the MFZ to the Change in Spreading Direction......Page 173
Comparison with Changes along the Kane Fracture Zone......Page 175
REFERENCES......Page 176
INTRODUCTION......Page 178
PREVIOUS WORK......Page 182
SIDESCAN SONAR AND BATHYMETRY DATA......Page 184
TECTONIC RECONSTRUCTION OF THECENTRAL PACIFIC BASIN......Page 186
REFERENCES......Page 191
INTRODUCTION......Page 193
Geologic Setting......Page 194
Samples Studied......Page 195
Sample Preparation......Page 198
Interpretation of Incremental-heating Experiments......Page 199
General Results......Page 200
Individual Seamount Ages......Page 208
Conventional and 40Ar/39Ar Total-Fusion ages......Page 214
Test of the Kinematic Hot Spot Hypothesis......Page 216
Test of the Fixed Hot Spot Hypothesis......Page 217
Comparisons with the Pacific Apparent Polar Wander Path......Page 218
CONCLUSIONS......Page 219
REFERENCES......Page 220
INTRODUCTION......Page 222
PETROGRAPHY AND MINERAL CHEMISTRY......Page 224
WHOLE ROCK MAJOR AND TRACE ELEMENT GEOCHEMISTRY......Page 225
SR AND PB ISOTOPE RATIOS......Page 227
SPATIAL VARIATIONS IN TRACE ELEMENT AND ISOTOPE RATIOS......Page 228
ORIGIN OF THE LINE ISLANDS CHAIN......Page 229
SUMMARY......Page 234
REFERENCES......Page 235
INTRODUCTION......Page 237
Samples and Methods......Page 239
Results......Page 240
Samples and Methods......Page 243
Results......Page 246
Melting Conditions of Plateau Magmas......Page 255
Relation of Site 803 Basalts to Other Sites......Page 260
Louisville Hotspot Connection......Page 261
CONCLUSIONS......Page 262
REFERENCES......Page 263
INTRODUCTION......Page 266
Wentworth Seamount Chain......Page 268
Analytical Techniques......Page 269
Wentworth Seamount Chain Results......Page 270
Hess Rise Results......Page 274
Constraints on the origin of Hess Rise......Page 278
REFERENCES......Page 279
INTRODUCTION......Page 281
Operation Crossroads......Page 282
Gravity......Page 283
Results from Nearby DSDP Sites......Page 284
Results from More Recent Dredging......Page 285
Results......Page 286
Wodejebato Guyot......Page 289
Ruwituntun......Page 294
Loen......Page 295
Lobbadede......Page 298
Lewa......Page 299
SUMMARY OF VOLCANISM, REEF BUILDING AND UPLIFT......Page 300
An Alternative Test for A Hotspot Origin......Page 301
CONCLUSIONS......Page 302
REFERENCES......Page 305
INTRODUCTION......Page 308
PREVIOUS WORK......Page 309
Rock Types......Page 311
Radiometric ages of dredged volcanic rocks from guyots......Page 312
Origin of NW Pacific Cretaceous Seamounts in South Pacific......Page 315
Summit Regions with Shallow-water Carbonate Sediments......Page 316
Paleontological Ages of Sediments......Page 322
PALEODEPTHS AND ELASTIC PLATE THICKNESS OF LITHOSPHERE......Page 323
Paleomagnetic poles......Page 324
Conclusions from seamount paleomagnetic data......Page 326
Comparisons of predictions from seamount magnetic data and hot-spot models......Page 328
Late Albian emergence......Page 330
CONCLUSIONS......Page 332
REFERENCES......Page 333
INTRODUCTION......Page 336
METHODS......Page 337
Medium-scale morphology......Page 338
Atoll structures......Page 343
Guyots with thin shallow-water limestone deposits......Page 345
Strictly volcanic guyots......Page 351
STRUCTURAL AND TECTONIC DEFORMATION......Page 356
Cretaceous Atolls......Page 360
ORIGIN OF EROSIONAL TOPOGRAPHY......Page 361
TIMING OF THE EROSION......Page 362
INFERENCES FROM GUYOTS ON THE TECTONIC HISTORY OF THE WESTERN PACIFIC.......Page 363
REFERENCES......Page 365
INTRODUCTION......Page 368
BACKGROUND......Page 369
METHODS......Page 371
GEOMORPHIC DESCRIPTION......Page 372
Southern Flank......Page 374
Flank Ridges......Page 375
Drowned Carbonate Pla tform......Page 379
DISCUSSION......Page 382
Model for the Geologic Evolution of Wodejebato Guyot......Page 383
REFERENCES......Page 385
INTRODUCTION......Page 387
WESTERN PACIFIC SEAMOUNT POLES......Page 388
METHODS AND MODELING PROCEDURES......Page 389
BATHYMETRIC DATA AND MODELS AND MAGNETIC DATA OF LO-EN GUYOT......Page 390
RESULTS......Page 393
Evaluation of Some Assumptions......Page 395
Age of Lo- En......Page 397
REFERENCES......Page 399
INTRODUCTION......Page 401
Pacific Apparent Polar Wander Path......Page 404
Geologic Setting......Page 405
Geophysical Data......Page 406
Bathymetry and Magnetic Anomaly Maps......Page 408
Magnetic Inversions......Page 409
RESULTS......Page 411
DISCUSSION......Page 412
Paleomagnetic Data: Errors and Limitations......Page 413
Magnetization Intensities......Page 414
Paleolatitudes......Page 415
APPENDIX......Page 416
REFERENCES......Page 434