Preface ....................................................... XII
1 Contractional theory, continental drift and plate tectonics ...l
Plate tectonics - a change in the paradigm of the geosciences ... 1
Early history of geodynamic thought ............................. 1
From continental drift to plate tectonics ....................... 2
The plate tectonic concept ...................................... 4
The pattern of magnetic polarity stripes ........................ 8
Plate motions and earthquake zones .............................. 8
Two kinds of continental margins ............................... 11
Magmatism and plate tectonics .................................. 11
What drives the plates and what slows them down? ............... 12
Collision and mountain building ................................ 12
2 Plate movements and their geometric relationships ........... 15
Helpful transform faults ....................................... 15
Relative movements and triple junctions ........................ 16
Two RTF triple junctions off North America .................. 18
Relative plate velocities - past and present ................... 20
Direct measurement of plate movements .......................... 21
Apparent contradictions in the plate motion pattern ............ 22
Fault-plane-solutions of earthquakes ........................ 23
Seismic tomography .......................................... 25
3 Continental graben structures ............................... 27
Active and passive graben structures ........................ 28
Symmetric and asymmetric crustal extension ..................... 28
Sediments and ore deposits in graben structures ................ 29
Volcanism in graben structures ................................. 30
The Upper Rhine Graben in Germany .............................. 31
The history of the Upper Rhine Graben .......................... 32
The Upper Rhine Graben in the Middle European stress field .. 33
Magmatism and heat flow in the Upper Rhine Graben .............. 34
The large East African rift system ............................. 34
The Afar Depression ......................................... 37
The Red Sea - from rift to drift ............................... 37
The extensional area of the Basin and Range Province ........... 39
The development of metamorphic domes ........................... 40
A brief history of the Basin and Range Province ................ 41
4 Passive continental margins and abyssal plains .............. 43
Continuous subsidence of the continental margins ............... 43
The sedimentary trap at a passive continental margin ........... 44
Tracts of sequence stratigraphy ............................. 45
Processes on continental margins ............................... 46
Petroleum deposits - the economic signifi-cance of passive
continental margins ............................................ 48
The Atlantic - an ocean opens in an intricate manner ........... 48
Pangaea and Panthalassa ..................................... 49
The large abyssal plains ....................................... 51
Sediments of the abyssal plains ................................ 52
Manganese nodules from the deep sea ......................... 54
Facies changes on the large oceanic conveyor belt .............. 55
The Bengal deep sea fan ..................................... 56
5 Mid-ocean ridges ............................................ 59
Topography of the ridges ....................................... 59
Generation of oceanic lithosphere .............................. 60
Rocks of the oceanic crust ..................................... 61
Pillow lavas ................................................ 62
Seismic layers .............................................. 64
Basalts of mid-ocean ridges .................................... 65
Fast and slow spreading ridges and rocks of the lithospheric
mantle ......................................................... 65
Segmentation of ridges by faults ............................... 67
Graben formation in the Atlantic ............................... 67
An oceanic crustal profile in the Atlantic Ocean ............ 68
Black and white smokers ........................................ 68
Ocean floor metamorphism ....................................... 70
Chromite deposits .............................................. 71
Ophiolites ..................................................... 71
The ophiolite of the Semail Nappe in Oman ...................... 72
Metamorphic sole ............................................ 72
Alpine-Mediterranean ophiolites ................................ 72
6 Hot Spots ................................................... 75
Hot spots and mid-ocean ridges ................................. 77
The mysterious D" layer and the dented Earth ................... 77
Hot spots of Pangaea ........................................ 78
Hot spot tracks in the ocean ................................... 80
A guyot evolves ............................................. 82
Hot spot tracks on the continent ............................... 82
Flood and trap basalts ......................................... 84
The Azores - hot, cold or wet spot? ............................ 85
Hawaii - a typical oceanic hot spot ............................ 86
Iceland ........................................................ 87
Yellowstone .................................................... 87
The superplume event in the Cretaceous ......................... 88
7 Subduction zones, island arcs and active continental
margins ..................................................... 91
Structure of plate margin systems with subduction zones ........ 91
Spontaneous and forced subduction: Mariana- and Chile-type
subduction ..................................................... 93
What is the reason for the arcuate shape of island arcs? .... 94
Deep sea trenches as sediment traps ............................ 96
Accretionary wedge and outer ridge ............................. 97
The accretionary wedge of the Sunda Arc ..................... 99
Subduction erosion instead of accretion ....................... 100
Mud volcanoes .............................................. 101
The forearc basin ............................................. 103
Earthquakes and Benioff zones ................................. 103
The Shigatse Flysch in Tibet ............................... 104
The secret of deep earthquakes ................................ 107
High-pressure or subduction metamorphism ...................... 109
Ultrahigh-pressure metamorphic rocks ....................... 111
Rapid burial, rapid uplift ................................. 112
Subduction-related magmatism - a paradox? ..................... 113
Rocks of the magmatic zone .................................... 114
Zonation of magmas in space and time .......................... 116
Explosive stratovolcanoes as indicators for subduction
magmatism ..................................................... 117
Isotopic signatures and the influence of continental
crust ...................................................... 118
Metamorphism in the magmatic belt ............................. 119
Paired metamorphic belts ................................... 119
Ore deposits in the magmatic belt ............................. 120
The backarc basin ............................................. 120
Splitting of intra-oceanic island arcs ..................... 122
Gravity and heat flow ......................................... 122
Subduction and collision ...................................... 122
8 Transform faults ........................................... 123
Oceanic transform faults ...................................... 123
Fracture zones in the ocean floor ............................. 123
Continental transform faults .................................. 125
San Andreas - the infamous transform fault of California ...... 127
The North Anatolian Fault in Asia Minor and the Alpine Fault
in New Zealand ................................................ 129
9 Terranes ................................................... 131
Documenting terranes .......................................... 132
Terranes in the North American Cordillera ..................... 134
Suspect terranes in Mexico and Middle America ................. 138
10 Early Precambrian plate tectonics .......................... 139
The oldest rocks and minerals .............................. 140
Greenstone-granite belts ...................................... 141
Granulite-gneiss belts ........................................ 143
Komatiites ................................................. 144
Towards an Archean plate tectonic model ....................... 145
The growth of continents ...................................... 146
Possible younger equivalents of greenstone-granite belts ...... 147
The Great Dike of Zimbabwe ................................. 147
11 Plate tectonics and mountain building ...................... 149
Types of active continental margins within orogenic styles .... 149
Continent-continent collision ................................. 152
Uplift, erosion, and elevation of mountains ................... 154
Collapse and crustal escape ................................... 158
12 Old orogens ................................................ 159
2500-2000 million years old ophiolites ........................ 159
The Wopmay orogen in Canada ................................... 160
The Grenville orogenic cycle and the formation of the
supercontinent Rodinia ........................................ 160
The Panafrican orogeny and the formation of Gondwana .......... 160
The Caledonides - a Wilson cycle around the Iapetus Ocean ..... 161
The significance of Scotland and the Greek mythology ....... 162
The Variscides - a broad mountain belt in central Europe ...... 163
A Variscan suture in the southern Black Forest ................ 165
The Variscan orogen in the Alps ............................ 165
Paleozoic mountain building in eastern and southern North
America ....................................................... 167
How many orogenies? ........................................ 169
13 Young orogens - the Earth's loftiest places ................ 171
The Himalayas - a mountain range with superlatives ............ 172
Tectonic history of the Himalayas ............................. 172
Nanga Parbat and Namche Barwa syntaxis ..................... 174
The Alps - an untypical but classic orogen .................... 174
Brief history of Alpine evolution ............................. 176
Lateral tectonic extrusion in the Alps ..................... 178
The North American Cordillera - a different style of orogen ... 179
Laramide Rocky Mountains - an orogenic mystery solved ......... 185
Epilog ........................................................ 187
Glossary ...................................................... 189
References .................................................... 199
Keyword Index ................................................. 207
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