1. Kinds of Faults

2. Faults
Is a break in Earth’s crust where slabs of crust slip past each other.
Usually occur along plate boundaries , where the forces of plate motion compress, pull, or shear the crust so much that the crust breaks.

3. Three Types of Faults
Normal Faults
Reverse Faults
Strike-Slip Faults

4. Fault Terminology
Fault Plane - the plane along which the rock or crustal material has fractured
Hanging Wall Block - the rock material which lies above the fault plane
Footwall Block - the rock material which lies below the fault plane.

5. Hanging vs. Foot The footwall of a fault is always under the fault
The hanging wall of a fault is always above the fault

7. Normal Faults Caused by tension forces where plates diverge
The fault is at an angle
One block lies above the fault (hanging wall)
The other block lies below the fault (footwall)
When movement occurs along a normal fault, the hanging wall slips downward

8. Normal Faults

9. Normal Fault
Footwall
Hanging Wall

10. Normal Faults

11. Normal Faults

12. Normal Faults

13. Reverse Faults
Caused by compression forces along convergent plate boundaries
Has the same structure as a normal fault, but blocks move in opposite direction
One side lies at an angle above the other
Where the hanging wall is displaced upward relative to the footwall
OR where the footwall is displaced downward relative to the hanging wall

14. Reverse Fault

15. Reverse Fault
Hanging Wall
Footwall

16. Reverse Fault

17. Reverse Fault

18. Reverse Fault

19. Strike-Slip Fault Created by shearing along transform boundaries
Rocks on either side of fault slip past each other sideways with little up-or-down motion

20. Strike-Slip Faults

21. Strike-Slip Fault

22. Strike-Slip Fault

23. Strike-Slip Fault

24. Strike-Slip Fault

25. Whose Fault?
Side View

26. Whose Fault?
Side View

27. Whose Fault?
Birds-eye View

28. Whose Fault?
Side View

29. Whose Fault?
Side View

30. Whose Fault?
Birds-eye View

31. Whose Fault?
Side View