FAULT TYPES By Ashlyn Boswell

Strike Slip Strike Slip Fault NormalNormal Fault ReverseReverse Fault ThrustThrust Fault

Strike Slip Fault  The most famous strike slip fault in the United States is the San Andreas Fault in California.  Earthquakes are most common along strike slip faults.  A strike slip fault occurs when two plates slide past one another in a parallel motion.

Normal Fault  Normal faults exist everywhere in the United States, but they are most prevalent in the Rocky Mountain areas of Utah.  Normal faults occur through a force called tension, which is the pulling apart of tectonic plates.  In a normal fault, the footwall is above the hanging wall. OL101/study/Images/NormalFault.gif

Reverse Fault  The reverse fault that we will be focused on are the reverse faults close to Seattle, Washington.  Reverse faults are caused by a force called compression, which is the pushing together of tectonic plates.  In a reverse fault, the hanging wall is above the footwall /study/Images/ReverseFault.gif

Thrust Fault  The thrust fault we will by studying is the Mississippian Madison Formation in Montana.  A thrust fault is caused by the compression force, which is the pushing together of two tectonic plates.  A thrust fault is very similar to a reverse fault, but the fault plane is less than thirty degrees in a thrust fault. L101/study/Images/Thrust.gif

Quiz Question 1: What type of fault most commonly produces Earthquakes? Answer…

Quiz Question 2: What type of fault has a fault plane of less than thirty degrees? Answer…

Quiz Question 3: What type of fault is caused by tension? Answer…

Quiz Question 4: Which fault type is characterized by the footwall being pressed under the hanging wall? Answer…