Gondwana Six: Structure, Tectonics, and Geophysics

Gondwana Six:Structure, Tectonics,and Geophysics......Page 1
Gondwana Six:Structure, Tectonics,and Geophysics......Page 4
CONTENTS......Page 7
PREFACE......Page 9
ACKNOWLEDGMENT S......Page 10
Ross Ice Shelf Profile......Page 11
Siple Coast Profile......Page 14
References......Page 17
Enhancement of Satellite Magnetic Anomalies for Geologic Analysis......Page 18
Geologic Implications of Radially Polarized MAGSAT Anomalies......Page 21
References......Page 23
Reconstruction......Page 25
References......Page 30
Introduction......Page 32
Discussion......Page 34
References......Page 35
The Bowers Terrane......Page 37
The Robertson Bay Terrane......Page 38
Pre-Ordovician Isotopic Ages......Page 40
Rb-Sr Whole-Rock Dating of Ordovician Events......Page 44
K-Ar Dating of Metapelites and K-Arand Rb-Sr Dating of Minerals......Page 48
The Devonian/Carboniferous Admiralty Intrusives......Page 49
References......Page 51
Tectonic Comparison......Page 54
Lithostratigraphic Comparisons......Page 58
Where Does New Zealand Fit?......Page 61
Interpretation......Page 63
Central Belt......Page 67
References......Page 68
Background......Page 72
Discussion......Page 75
Summary......Page 78
References......Page 79
Introduction......Page 81
The Pannotios Belts......Page 82
References......Page 88
Geological and Tectonic Setting......Page 92
Paired Metamorphic Belts......Page 94
Subduction Complex......Page 97
Thrust Belts: Structural Evidence for Subduction......Page 98
Granitic Intrusions......Page 100
Interpretation: Previous Models......Page 102
Conclusions......Page 103
References......Page 105
Field Program......Page 109
References......Page 110
Data Acquisition and Processing......Page 111
Bedrock Morphology and Magnetic Anomalies......Page 113
Interpretation of the Magnetic Anomalies......Page 114
Summary and Conclusions......Page 116
References......Page 117
Introduction......Page 118
Lewis Nunatak......Page 121
Haag Nunataks......Page 122
Ellsworth Domain......Page 123
Marginal Domain......Page 125
Tectonic Synthesis......Page 126
References......Page 128
Methods......Page 130
Field Relations, Mineralogy, and Petrography......Page 131
Geochemistry and Discrimination Diagrams......Page 133
Correlations......Page 137
References......Page 138
Methods......Page 140
Geologic Setting......Page 141
Field Relations of Granitic Rocks......Page 142
Geochemistry......Page 144
Source of Granitic Magmas......Page 146
Tectonic Setting......Page 148
References......Page 149
New Geochronological Data......Page 152
Discussion and Conclusions......Page 159
References......Page 161
West Antarctica and the Pacific Margin of Gondwanaland......Page 162
Ellsworth-Whitmore Mountains Crustal Block......Page 163
Tectonic Interpretation......Page 168
References......Page 171
Introduction......Page 173
Extent of the Ellsworth-Whitmore Mountains Crustal Block......Page 174
Haag Nunataks and the Basement of the Ellsworth-Whitmore Mountains Crustal Block......Page 176
Igneous Activity......Page 178
Mesozoic-Cenozoic Displacement and Extension......Page 179
Conclusion......Page 180
References......Page 181
Introduction......Page 183
Sedimentary Rocks Correlated With the Latady Formation......Page 185
Sedimentary Rocks Whose Ages Are Unknown......Page 187
Discussion......Page 188
References......Page 189
Introduction......Page 190
Evolution of the Mesozoic Magmatic Arc......Page 191
Falkland Islands......Page 193
Discussion......Page 194
References......Page 195
Introduction......Page 198
Discussion......Page 202
References......Page 205
Rock Units......Page 207
Deformation in the Magmatic Arc:Major Shear Zones and Faults......Page 211
Arc Evolution in Northern Palmer Land......Page 212
Conclusions......Page 215
References......Page 216
Eastern Belt EB......Page 218
Western Belt......Page 220
Geochronology......Page 222
Discussion......Page 223
References......Page 224
Introduction......Page 225
Tectonometamorphic Zonation in theBasement Between Salta and Tucuman......Page 227
The Character of Crustal Thickening......Page 230
Proposed Comprehensive Geodynamic Interpretation......Page 231
Conclusions......Page 233
References......Page 234
Introduction......Page 236
Main Cordillera......Page 238
Coastal Cordillera......Page 239
Main Cordillera, Matahuaico Formation......Page 240
Coastal Cordillera, Cifuncho Formation......Page 241
Discussion......Page 242
References......Page 246
Age Determination and Discussionof Radiolarian Assemblages......Page 248
Systematic Paleontology......Page 251
References......Page 254
Paleozoic Geology of Northern Chile......Page 256
Devonian to Early Carboniferous Sedimentaryand Volcanic Rocks Between 25°S and 29 ° S......Page 258
Origin of the Mélange......Page 260
Origin of the Deformation......Page 262
Summary and Tectonic Setting......Page 263
References......Page 264
Carboniferous to Early TriassicPrebreakup Phase......Page 266
Late Triassic to Early CretaceousBreakup Phase......Page 270
Early Cretaceous to RecentPostbreakup Phase......Page 274
References......Page 276
Introduction......Page 281
Provenance of the Puncoviscana Formation Sediments......Page 283
Facies Analysis and Paleogeography......Page 285
Conclusions......Page 286
References......Page 287
Introduction......Page 288
The Northern Kraul Mountains......Page 290
The Northern Ahlmann Ridge......Page 294
Discussion and Conclusions......Page 296
References......Page 299
Two Complexes in Eastern Queen Maud Land......Page 301
LUtzow-Holm Complex in Gondwanaland......Page 307
References......Page 308
Tectonics of the Barotse Basin......Page 311
Tectonics of the Kafue and Mid-Zambezi Grabens......Page 312
Conclusions......Page 313
References......Page 314
SYMPOSIUM PARTICIPANTS......Page 315