Chapter 19 Plate Tectonics

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Chapter 19Plate Tectonics
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Divergent Plate Boundaries

• Transform Boundaries

3
Transforms vs. Fracture Zones
4
Models of Early Continental Breakup
5
Rifting to Ocean Basin Formation
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Passive Upwelling
7
East African Rift System
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Red Sea Rift from Space
Arabian Plate
SE
Sinai Peninsula
African Plate
9
Rifted Passive Margin
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Transform Boundaries

• Transform Boundary Types
• Ridge - Ridge
• Ridge - Trench
• Trench - Trench

11
Ridge - Transform Morphology
Oceanic Plates
Continental Plates
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Convergent Plate Boundaries

• Ocean-Ocean Convergence
• Ocean-Continent Convergence
• Continent-Continent Convergence

13
Ocean - Ocean Plate Convergence
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Accretionary Prism Development by Offscraping
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Trench Curvature on a Sphere
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Slab Angle vs. Arc-Trench Separation
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Arc - Trench Migration
Overlying Plate Forcing
Subducting Plate Forcing
18
Ocean - Continent Convergence
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Continent-Continent Collision
20
Backarc Spreading

• The Motion of Plate Boundaries
• Plate Size

21
Backarc SpreadingScenarios
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Causes of Backarc Spreading
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Evolution of San Andreas System
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The Attractiveness of Plate Tectonics

• What Causes Plate Motions?
• Mantle Plumes and Hot Spots
• Ridge Push
• Slab Pull
• The Relationship Between Plate Tectonics and Ore
  Deposits

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Ridge Push
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Slab Pull
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Trench Suction
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Global Distribution of Putative Mantle Plumes or
Hot Spots
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Consequences of Mantle Plumes
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Continental BreakupCaused by a Mantle Plume
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Plume-Rift Animation
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Radial Rift Example
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Continental Breakup Driven by Multiple Mantle
Plumes
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Hot Spot Tracks
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Hawaiian Volcanics Age Progression
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Hydrothermal Orogenesis and Divergent Plate Motion
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Island Arc Orogenesis of Bedded Ore Deposits
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Possible Relationship of Western US Ore Belts to
Subduction Geometry