Normal Fault Hanging Wall And Footwall

Low angle normal faults with regional tectonic significance may be designated detachment faults.

Normal fault hanging wall and footwall.

Normal faults are common. A type of fault in which the hanging wall moves down relative to the footwall and the fault surface dips steeply commonly from 50 o to 90 o groups of normal faults can produce horst and graben topography or a series of relatively high and low standing fault blocks as seen in areas where the crust is rifting or being pulled apart by plate tectonic activity. Any fault plane can be completely described with two measurements. An upthrown block between two normal faults dipping away from each other is a horst.

Where the fault plane is sloping as with normal and reverse faults the upper side is the hanging wall and the lower side is the footwall. If you imagine undoing the motion of a normal fault you will undo the stretching and thus shorten the horizontal distance between two points on either side of the fault. A downthrown block between two normal faults dipping towards each other is a graben. Normal faults occur in areas undergoing extension stretching.

In a normal fault the hanging wall moves downward relative to the footwall. When the fault plane is vertical there is no hanging wall or footwall. If the hanging wall drops relative to the footwall you have a normal fault. They bound many of the mountain ranges of the world and many of the rift valleys found along spreading margins.

Other articles where normal fault is discussed. Normal dip slip faults are produced by vertical compression as earth s crust lengthens.