Faults

1. 
   
   
     Caused by movement within Earth’s crust
   
   
   
2. 
   
   
     Are fractures in the crust where a lot of movement occurs
   
   
   
3. 
   
   
     Located along plate boundaries
   
   
   
4. 
   
   
     Causes deformation of rock and earthquakes
   
   
   
5. 
   
   
     Assist geologist in determining movement of forces in Earth’s crust 

Types of movement:

Can be horizontal, vertical, or a combination

n      Fault movements are mainly vertical

n      Often called dip slip faults

n      Can be either up or down a plane

n      Rocks on one side of the fault can be pushed up or dropped down in contrast to the other side.

n      To see the difference between the two faults two terms are used.  The rock that is higher than the fault surface is called the hanging wall.  (you can hang a coat from it)

n      The rock that is lower is called the footwall (you can walk on it).

Normal Fault Slip

n      The hanging wall moves downward in relation to the footwall.

n       (animation)

Reverse Fault

n      Reverse faults happen when the hanging wall moves upward in relation to the footwall.

n      Thrust faults are reverse faults with a low angle.

n       Animation

Strike Slip Faults

•       Also called transform faults

•       Horizontal movement

•       Many are associated with plate boundaries

•       Also called shear fault (like ripping paper)

Comparison of Slip Faults

n      The kind of  transform fault can be determined when you look at fault.  No matter from what side you are looking at the fault, if the land across from the  fault was moved left it is a left lateral fault.

n      Left Lateral Fault Slip (animation)

n      If the land has moved right it is a right lateral fault slip

n      Right Lateral Fault Slip (animation)