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Foreword VII
Yellowstone country 1
A geological preview 4
Geologic history of the Yellowstone region 7
The nature of the rocks reveals their origins 7
The oldest rocks 7
The deposits of the shifting seas 13
The first mountain-building episode 19
Volcanic activity 23
A quiet period 31
More mountain building and deep erosion 32
Formation of the Yellowstone caldera 34
The eruption 38
The collapse 39
The outpouring of lava 44
Final sculpturing of the landscape 53
Glaciation 53
Running water—canyons and waterfalls 63
Grand Canyon of the Yellowstone 64
Hot-water and steam phenomena 71
How a thermal system operates 71
Hot-spring deposits and algae 75
Hot springs and geysers 79
Mudpots 82
Fumaroles 85
Thermal explosions 85
Faulting and its control of thermal activity 86
Earthquakes 87
The Park and man 89
Acknowledgments 90
Selected additional reading 91