1. Chapter 11, Section 1 Forces Inside the Earth

2. Elastic Deformation
The ability of an object to bend and stretch without breaking.

3. Elastic Limit
The point at which an object that has elasticity breaks.

4. Rocks and Elasticity
Rocks will bend and stretch in response to forces within the Earth until they reach an elastic limit, at which time they break.

5. Review of Forces Compression Tension Shearing
Pushes/squeezes rocks together
Tension
Pulls rocks apart
Shearing
Slides rocks past each other

6. Faults Occur when rocks reach an elastic limit and break.
Rocks on either side of the break move.

7. Anatomy of a Fault Fault Plane Hanging Wall Foot Wall
Surface of the fault.
Hanging Wall
Rocks above the fault plane.
Foot Wall
Rocks below the fault plane.

8. Faults
3 types:
Normal faults
Reverse faults
Strike-slip faults

9. Faults
Normal Fault
Rocks in the hanging wall move down relative to the rocks in the footwall.
Caused by tension

11. Faults
Reverse Fault
Rocks in the hanging wall move up relative to the rocks in the footwall.
Caused by compression.
Thrust fault
Special type of reverse fault where the rocks in the hanging wall are pushed up and over the rocks in the foot wall at a very low angle.
Common in steep mountains.

14. Faults Strike-slip faults
Rocks on either side of the fault plane are moving past each other with little up or down motion.