1. Plate Tectonics and Mountain Building
GPH 111

2. Plate Tectonics and Mountain Building Game plan:
Intro to Plate Tectonics, Wegner, and Pangea
Major Plate Boundaries
Terrain Accretion and Continental Shields
Plate Tectonics and Mountains
Stress and Strain – Folding and Faulting

3. Continental Movements: Pangea to Now… Super-Continent Cycles

4. Continental Movements
Australia - the fastest moving continent, 6.5 cm / year

5. Major Plate Boundaries…
Convergent
Divergent
Transform
Hot Spots – not technically a boundary, but cool and interesting none the less

6. Convergent Plate Boundary
Continent – Continent, Continent – Ocean, and Ocean - Ocean

7. Convergent Plate Boundary
Continent – Continent, Continent – Ocean, and Ocean - Ocean

8. Convergent Plate Boundary
Continent – Continent, Continent – Ocean, and Ocean - Ocean
Mariana Trench - 35,802 feet deep at the deepest, this is where plates dive into the mantle. That is 8 tons per square inch…

9. Divergent Plate Boundary
Mid-Ocean Ridges

10. Divergent Plate Boundary
Mid-Ocean Ridges
Generates new ocean sea floor over time - driven by convective currents.

11. Divergent Plate Boundary
Mid-Atlantic Ridge

12. Oldest ocean floor ~180 million years
Divergent Plate Boundary
Oldest ocean floor ~180 million years

13. Transform Boundaries
San Andreas Fault

14. Hot Spots
Think:
Balloon on a string…
Hawaii

15. Hot Spots
Columbia Plateau and Yellowstone

16. Plate Tectonics and Mountain Building:
Terrain Accretion and Continental Shields
Plate Tectonics and Mountains
- Convergent Boundaries
- Fault Block Mountains
- Isostatic Mountains

17. Continental Shields
Older nucleuses that younger crust (objects like Japan) adheres to are called continental shields and the process is called terrain accretion

18. Plate Convergence Mountains

19. Isostatic Mountains - Superstitions
Continents behave like wooden blocks in water…
Mountains Uplift as they are eroded… Basins depress as they fill…

20. Isostatic Mountains
Old volcanic center erupted 18 million years ago, and collapsed on itself, and then rebounded into the current mountain range
Superstition Mountains

21. Fault Block Mountains
Nevada, US

22. Plate Tectonics and Mountain Building:
Stress and Strain
Faulting
- Normal Fault
- Reverse Fault
- Strike Slip Fault

23. Stress and Strain My Snickers Tension Compression Shear
Stress - force on the rock; Strain - the resulting response

24. Types of Faults
Your Snickers

25. a.
Slide #1 c. b.

26. a.
Slide #2 c. b.

27. a.
Slide #3 c. b.

28. a.
Slide #4 c. b.

29. Things to Know:
Alfred Wegner and his early proposal of Continental Drift, but known today as plate tectonics
The energy source that drives plate tectonics
The name for the most recent super continent, Pangea
The major plate boundaries: convergent, divergent, and transform, and also hot spots
Continental shields and terrain accretion
Three ways to generate mountains: convergent plate boundaries, Isostatic, and Fault Block
The difference between stress and strain
Under what circumstances will a rock behave in a ductile or brittle fashion
The major fault types: normal, reverse, and strike slip (be able to diagram them)
Help: Chapter TL