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Fault Motion
These animations are very elementary examples
of fault motion intended for simple demonstrations. For more about
faults see the NOAA
slide show and information page - a rich source of images
and textual information.
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1] DIP-SLIP FAULTS
a) Normal Fault
In a normal fault, the block above the fault moves down relative
to the block below the fault. This fault motion is caused by
tensional forces and results in extension. [Other names: normal-slip
fault, tensional fault or gravity fault] |
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b) Reverse Fault
In a reverse fault, the block above the fault moves up relative
to the block below the fault. This fault motion is caused by
compressional forces and results in shortening. A reverse fault
is called a thrust fault if the dip of the fault plane is small.
[Other names: thrust fault, reverse-slip fault or compressional
fault] |
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2] STRIKE-SLIP FAULT
In a strike-slip fault, the movement of blocks along a fault
is horizontal. If the block on the far side of the fault moves
to the left, as shown in this animation, the fault is called
left-lateral. If the block on the far side moves to the right,
the fault is called right-lateral. The fault motion of a strike-slip
fault is caused by shearing forces. [Other names: transcurrent
fault, lateral fault, tear fault or wrench fault] |
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3] OBLIQUE-SLIP FAULT
Oblique-slip faulting suggests both dip-slip faulting and strike-slip
faulting. It is caused by a combination of shearing and tension
of compressional forces. |
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