Rio Grande Rift: Tectonics and Magmatism

Title Page
......Page 2
Copyright
......Page 3
Foreword
......Page 4
Contents
......Page 7
EVOLUTION OF THE RIO GRANDE RIFT - A SUMMARY......Page 10
References......Page 13
A PLATE-TECTONIC MODEL FOR LATE CENOZOIC CRUSTAL SPREADING IN THE WESTERN UNITED STATES......Page 16
Introduction......Page 17
Locus and Time of Crustal Extension......Page 19
Geophysical Characteristics of the Extended Region......Page 30
An Interpretive Kinematic. Model......Page 34
References......Page 37
Introduction......Page 42
General Features and Setting......Page 45
Igneous Rocks......Page 47
San Luis Valley......Page 49
Sangre de Cristo Range......Page 52
Upper Arkansas Valley......Page 53
South Park and Southern Front  Range......Page 55
Gore-Tenmile Range and Vicinity......Page 56
Northern Termination......Page 57
Northern Colorado......Page 58
Mineralization and Geothermal Features......Page 59
Age of Rifting......Page 60
Relation To Regional Tectonics......Page 61
References......Page 62
Introduction......Page 66
Rift Borders......Page 68
Basin Structures......Page 72
Development and Origin......Page 76
References......Page 78
Introduction......Page 80
Previous Work......Page 81
Stratigraphy......Page 83
Faults......Page 87
Geologic History......Page 89
Relation To Other Rift Basins......Page 91
References......Page 92
Introduction......Page 96
The southern end of the Rio Grande rift......Page 97
Deep conditions beneath the southern Rio Grande rift......Page 102
Southern rift basalts and magma genesis......Page 105
Tectono-magmatic evolution of the southern Rio Grande rift......Page 107
Conclusions......Page 110
References......Page 111
Evaporite Tectonics......Page 116
Halite Behavior......Page 117
Fault Behavior in Evaporites......Page 118
Evidence of Rift Continuation......Page 119
Conclusions......Page 120
References......Page 121
Data and Analysis......Page 124
Results and Conclusions......Page 128
References......Page 134
CRUSTAL STRUCTURE ALONG THE RIO GRANDE RIFT FROM SEISMIC REFRACTION PROFILES......Page 136
Introduction......Page 137
Data Acquisition and Analysis......Page 138
Interpretation and Results......Page 139
Discussion......Page 147
Conclusions......Page 149
References......Page 150
SEISMICITY OF THE RIO GRANDE RIFT......Page 154
Earthquake Activity Prior to 1962......Page 155
Earthquake Activity After 1961......Page 159
NMT Seismic Studies of the Rio Grande Rift - Socorro Area......Page 163
LASL Seismic Studies of the Rio Grande Rift from 35°N to 37.5°N......Page 166
USGS Seismic Studies of the Rio Grande Rift from 34°N to 36°N......Page 171
Discussion......Page 173
References......Page 174
COCORP SEISMIC REFLECTION STUDIES OF THE RIO GRANDE RIFT......Page 178
Background......Page 179
Results......Page 181
Summary and Conclusions......Page 188
References......Page 191
Introduction......Page 194
Seismic Prospecting in the San Luis Valley......Page 195
Interpretation......Page 196
Conclusions......Page 200
References......Page 202
Introduction......Page 204
Geologic and Volcanic History......Page 205
Review of Geophysical Studies......Page 208
Petrology......Page 211
Crustal Evolution Model......Page 212
References......Page 215
Introduction......Page 218
Rio Grande Rift Magnetotelluric Study......Page 219
MT Soundings Within Continental Rift Zones......Page 223
Geoelectric Models of the Upper 60 Km in Continental Rift Zones......Page 225
Conclusions......Page 227
References......Page 229
RECENT VERTICAL CRUSTAL MOVEMENTS FROM LEVELING OBSERVATIONS IN THE VICINITY OF THE RIO GRANDE RIFT......Page 232
Data......Page 233
Discussion......Page 242
References......Page 243
Introduction......Page 246
Data......Page 247
The Magma Body......Page 250
Discussion......Page 259
References......Page 260
Introduction......Page 262
Comparison of Reported Heat-flow Data within Regions of the Southern Rocky Mountain Complex......Page 267
Discussion......Page 270
References......Page 274
Geothermal Data for Northern Mexico......Page 278
Temperature - Depth MOdels......Page 281
Discussion......Page 284
Conclusions......Page 285
References......Page 286
Introduction......Page 288
Structural Setting......Page 289
Pre-Rift and Early-Rift Ro cks......Page 291
Rocks of the Taos Plateau Vol canic Field......Page 295
Discussion......Page 306
References......Page 308
Introduction......Page 312
Structural Setting......Page 313
Pre-Rift and Early-Rift Rocks......Page 315
Rocks of the Taos Plateau Volcanic Field......Page 319
Discussion......Page 330
References......Page 332
Age of Spanish Peaks Magmatism......Page 336
Composition of the Igneous Rocks......Page 337
Magma Origin and Differentiation......Page 341
References......Page 344
Introduction......Page 378
Whole Rock Chemistry......Page 379
Petrography......Page 385
Mineral Chemistry......Page 391
Sr Data......Page 394
Trace Element Chemistry......Page 395
Discussion......Page 396
References......Page 402
The Trans-Pecos province......Page 405
Relation to the Rio Grande Rift......Page 407
Some larger-scale relations......Page 408
References......Page 413
Introduction......Page 416
Petrographic description of the inclusions......Page 417
Discussion......Page 425
References......Page 437
Introduction......Page 439
Summary of Events and Field Relations......Page 441
Petrogenesis......Page 445
Tectonic Synthesis......Page 449
Conclusions Concerning the Rio Grande Graben System......Page 455
References......Page 457