1. Plate Tectonics Inside Earth Chapter 1.5 Pages 42-47

2. Cracks in the Earth

3. Plate Tectonics • Scientist J. Tuzo Wilson in 1965 combined Continental Drift & Sea-Floor Spreading, creating… • Theory of Plate Tectonics: plates (pieces of Earth’s lithosphere) are in constant, slow motion, driven by convection currents in the mantle.

4. Earth’s Plates

5. Recall the Crust Climate • There are 3 types of boundaries in Plate Tectonic Theory • Convergent • Divergent • Transform • Each boundary creates a geologic feature depending on the type of crust involved • Continental • Oceanic

6. Convergent Boundaries Climate • Definition: two plates move towards each other. (Collision Boundary) • What geologic features do Continental crust collisions create?

7. Convergent Boundaries • Geologic Features: • Cont/Cont collision forms mountains (Himalayas)

8. Convergent Boundaries • Geologic Features: • Cont/Ocean (Subduction boundary) • Denser Ocean plate subducts • Trenches, Volcanoes • Example: • Mt. St. Helens

10. Convergent Boundaries • Geologic Features: • Ocean/Ocean (Subduction boundary) • Denser Ocean plate subducts • Trenches, Volcanic Island Arc • Example: • Hawaii

11. Divergent Boundaries Climate • Definition: two plates moving apart • Geologic Features: forms a rift valley • Examples: • Great Rift Valley • Mid-Ocean Ridge

12. Transform Boundaries Pacific Plate North American Plate Climate • Definition: Two plates slide past each other in opposite directions • Geologic Features: • Faults:break in crust • Examples: • San Andreas Fault • Causes earthquakes

13. Boundary Diagrams Climate • Boundary: • Motion: • Features formed: • Examples: • Boundary:Transform • Motion:Slide past each other • Features formed:Fault • Examples:San Andreas Fault

14. Boundary Diagrams Cont. Crust Climate • Boundary: • Motion: • Crust: • Features formed: • Boundary:Convergent • Motion:Towards each other • Crust:Continental & Continental • Features formed: Mountain ranges

15. Boundary Diagrams Boundary Diagrams • Boundary: • Motion: • Features formed: • Boundary:Divergent • Motion: Pull apart, move away • Features formed:Mid-Ocean Ridge

16. Boundary Diagrams Climate • Boundary: • Motion: • Crust: • Features formed: • Boundary:Convergent • Motion:Towards each other • Crust:Oceanic & Oceanic • Features formed: Subduction, Trench, Volcanic island arc

17. Boundary Diagrams Climate • Boundary: • Motion: • Features formed: • Example: • Boundary:Divergent • Motion:Pull apart, move away • Features formed: Rift Valley • Example:Great Rift Valley

18. Boundary Diagrams Climate • Boundary: • Motion: • Crust: • Features formed: • Boundary:Convergent • Motion:Towards each other • Crust:Oceanic & Continental • Features formed:Subduction, Trench, Volcanoes