Earths Changing Surface

1
Earths Changing Surface

• Notes

2
Stress

• Force that pushes and pulls at the earths surface
  (crust) changing its shape and structure.
• Can change both continental and oceanic crust.

3
Three Types of Stress

1. Compression- squeezes rocks together
2. Tension- pulls rocks apart
3. Shearing- pushes rocks in opposite directions

4
(No Transcript)
5
Deformation

• Breaking, tilting and folding of rocks caused by
  stress.

6
Faulting

• A break or crack (fault) along which rocks move.
• Can move up, down or sideways.

7
Hanging Wall

• Rock above the fault.
• Sketch below

8
Foot Wall

• Rock below the fault.
• Sketch below

9
Normal Fault

• Tension causes the hanging wall to move down
  relative to the foot wall.

10
Reverse Fault

• Compression causes the hanging wall to move up
  relative to the foot wall.

11
Lateral Fault

• Shearing causes rocks to move side to side.

12
Thrust Fault

• Compression causes the hanging wall to slide over
  the foot wall.
• Older rocks move on top of the younger rocks.

13
Simulation

• http//www.iris.edu/gifs/animations/faults.htm

14
Fault Block Mountains and Rift Valleys

• Formed by two normal faults.

15
Folding

• Fold- a bend in a rock.
• Anticline- upward fold in a rock.
• Syncline- a downward fold in a rock.

16
Plateau

• Caused by flat top folds, vertical faulting and
  lava flow.