Continental Drift and Plate Tectonics

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Continental Drift and Plate Tectonics
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The Permian Ice Age Problem
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Wegeners Theory
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Confirmation of Continental Drift

• World War II technology
• International Geophysical Year (IGY) 1957-58
• Worldwide Standardized Seismic Network 1963-

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The Geomagnetic Reversal Time Scale
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Discovery of Sea-Floor Spreading
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Sea-Floor Spreading
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Where Does Ocean Crust Go?

• Hugo Benioff, 1954

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Benioffs Interpretation Updated
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Worldwide Standardized Seismic Network
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The Plate Tectonics Model
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The Plate Tectonics Model
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The Earths Plates
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Global Plate Motions
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What Drives It Convection
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How Plates Move
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Reconstructing Plate Movements
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Fit of Continents Across the Atlantic
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Present Day Atlantic
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Atlantic 65 m.y. ago
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A Subduction Zone
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Paleomagnetism
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Why Mountains are High
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Where the Plates Meet
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Terrane Accretion
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Terranes in Western North America
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Hot Spots