Stress and Faults

3 Types of Stress1. Tension: stress that pulls rock

apartRock gets thinner in the middle

2. Compression: stress that pushes rock together

3. Shearing: stress that pushes rock in opposite directions

FaultsA fault is a break in the earth’s crust.

Fault’s occur along plate boundaries where forces push and pull the earth’s plates.

3 Types of Faults1. Normal Fault: occurs when the rock above the fault (the hanging wall) moves down (along the footwall)Tension stress causes this type of faultCreates valleys

2. Reverse Fault: occurs when rock above the fault (H.W.) move up (along the F.W.)Compression stress causes this type of faultCreates mountains

3. Strike-Slip Fault: occurs when rock on either side of the fault move past each other in opposite directionsThere is no up or down motionShearing stress causes this type of faultExample: San Andreas Fault, Cal.