1. Earth’s Crust in Motion

2. Stress in the Crust
Earthquake is the shaking and trembling that results from the movement of rock beneath Earth’s surface.

3. Types of Stress
Shearing
Tension
Compression

4. Types of Stress

5. Faults
Strike-Slip Fault
Normal Fault
Reverse Fault

6. Strike-Slip Fault
Stress that causes Strike-Slip Faults:
Shearing

7. Strike-Slip Fault Example
The San Andreas Fault in California.

8. Normal Fault
Stress that causes Normal Fault is:
Tension

9. Normal Fault Example
The Sandia Mountains in New Mexico were created by a Normal Fault.

10. Reverse Fault
Stress that causes a reverse fault:
Compression

11. Reverse Fault Example
Mt Gould in Glacier National Park

12. Friction Along Faults
Little Friction- quicker movement, less force to overcome friction.
More Friction- stress must build up to move one plate past another. When stress is released more powerful earthquake can result.

13. Mountain Building Mountains Formed by Faulting.
Fault Block Mountains- Teton Range Wyoming
(2 normal faults)

14. Mountains by Folding
Folds are bends in rock that form when compression shortens and thickens part of Earth’s crust

15. Folded Mountains
Example: Himalayas and Alps

16. Anticlines and Synclines

17. Examples of Anticlines and Synclines
Anticline-Black Hills South Dakota
Syncline-Illinois Basin

18. South Dakota

19. Plateau
Example- Colorado Plateau including Four Corners (Arizona, Utah Colorado, New Mexico)