Fault Motion Animations : IRIS (original) (raw)

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.

| | 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] | | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | 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] | | | | | | 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] | | | 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. |