1. Forces in Earth’s Crust
Created by the Marvelous Mr. Christine
8th Grade Science

2. What does forces cause?

3. Are You Stressed Out
Stress: Force that acts on rock to change its shape or volume.
3 Types
Tension, Compression, and Shearing
Tension: Stretches rock so that it becomes thinner in the middle
Compression: Squeezes rock until it breaks or folds.
Shearing: Pushes mass of rock in opposite directions, in a sideways movement.

4. Tension

5. Compression

6. Shearing

7. You’re at Fault
Fault: A break in Earth’s crust where masses of rock slip past each other.
3 Types
Normal, Reverse, Strike-Slip

8. Normal Fault
Type of fault where hanging wall slides downward; caused by tension in crust

9. Reverse Fault
Type of fault where hanging wall slides upward; caused by compression

10. Strike-Slip Fault
Fault which rocks on either slide move past each other sideways with little up or down motion.

11. Principle of Original Horizontality
Sedimentary Rock are deposited in layers

12. Folding Earthquakes change the horizontality by folding.
Folding is where rock is compressed and changes its shape
Older Rock can now be found over younger rock

13. Anticline
Upward fold of rock formed by compression or Earth’s crust.

14. Syncline
Downward fold in rock formed by compression