1. MOVEMENT OF THE EARTH’S CRUST

2. Earth’s crust can be deformed through:
Faulting
Folding
Uplifting

3. How does the crust change it’s shape over time?
As rocks undergo stress (push-pull force)
they slowly change SHAPE and VOLUME
Stress causes breaking, tilting and folding
►DEFORMATION

4. 3 Types of Deformation
Compression - squeezes rocks together causing crustal rocks to be pushed higher and deeper.
Tension – pulls rocks apart causing crustal rocks to be thinner in the middle than at the ends.
Shearing – pushes rocks horizontally in two directions.

5. FAULTS - a break or crack along which rocks move
Hanging Wall – block of rocks above the fault.
Foot Wall – block of rocks below the fault.

6. Types of Faults
Normal Fault : tension causes the hanging wall to move down relative to the foot wall.
Reverse Fault : compression causes the hanging wall to move up relative to the foot wall.
Strike – Slip Fault : shearing causes the blocks of rock to move horizontally past one another.

7. Types
Normal Fault Reverse Fault Strike-slip Fault

8. Many Normal Faults in one area may create mountains & valleys.
Fault Block Mountains
Many Normal Faults in one area may create mountains & valleys.
Mountains formed by blocks of rock uplifted are called fault-block mountains. Ex : Grand Tetons, WY

9. Fold – a bend in a rock
Sometimes when stress is applied to crustal rocks, they bend but do not break
Anticline – upward fold
Syncline – downward fold

10. Normal Faults

11. Reverse Fault

12. Strike-Slip Faults

13. Folds & Faults