1. Chapter 11 Deformation of the Crust

2. What causes this to happen?
1. Plate Movement

3. 2. Isostatic Adjustment
change in weight of some parts of the crust causing it to move up and down and deform the crust
(glaciers, mountains)

4. Types of stress
1. Tensional: pulling apart; elongates or breaks rocks

5. 2. Compressional: pushes together; shortens rocks

6. 3. Shear: pushed in opposite horizontal directions, bends and/or twists rocks

7. Stress is stored in rocks as STRAIN
STRAIN greater than rock strength, deformation happens!

8. Results of Stress Folding Anticline Syncline Monocline 2. Fault Normal
Reverse
Thrust
Strike-Slip

9. Anticline
Looks like a dome...

11. Syncline
…looks like a bowl

15. …looks like a stair step
Monocline
…looks like a stair step

19. Results of Stress
2. Faulting: rocks fracture, then move

20. Hanging wall: you could hang a lantern from it...
Foot wall: you could put your foot on it...

21. …relative to the foot wall. Tensional stress.
A. normal fault, the hanging wall moves down...
…relative to the foot wall.
Tensional stress.

25. …relative to the foot wall. Compressional stress.
B. reverse fault, the hanging wall moves up...
…relative to the foot wall.
Compressional stress.

27. C. Thrust fault: type of reverse fault at a low angle.

29. d. Strike-slip fault
Rock slide past each other on the horizontal plane
Shear stress
Transform boundaries
San Andreas fault