Application Phase

1. Explain that faults are often (but not always) found near plate boundaries and that each type of fault is frequently associated with specific types of plate movements. However, you can probably find all types of fault movement associated with each type of plate boundary.

   1. Normal faults are often associated with divergent (tensional) boundaries.
   2. Thrust faults are often associated with convergent (compressional) boundaries.
   3. Strike-slip faults are often associated with transform (sliding) boundaries.

2. Ask the following questions:

   1. What kind of faults would you expect to find in the Himalaya Mountains? Why?
   2. What kind of faults would you expect to find along the Mid-Atlantic Ridge? Why?
   3. What kind of fault is the San Andreas Fault? Is California likely to "fall off into the Pacific Ocean"? Why?

3. Explain that not all faults are associated with plate boundaries. Explain that there is a broad range of faults based on type, linear extension, displacement, age, current or historical activity and location on contintental or oceanic crust. Have students research examples of non-plate boundary faults.

4. Explain to students that the stresses and strains in the earth's upper layers are induced by many causes: thermal expansion and contraction, gravitational forces, solid-earth tidal forces, specific volume changes because of mineral phase transitions, etc. Faulting is one of the various manners of mechanical adjustment or release of such stress and strain.

5. Have students research and report on the types of faults found in your state?

Extension

1. Have students Identify the fault movements in the recent Loma Prieta, California earthquake.

2. Have students research the fault histories and recent theories concerning the Northridge, California Earthquake, the New Madrid, Missouri , and the Anchorage, Alaska fault zones.

Coloring Key