Normal dip-slip faults are produced by vertical compression as Earth’s crust lengthens . The hanging wall slides down relative to the footwall. Normal faults are common; they bound many of the mountain ranges of the world and many of the rift valleys found along spreading margins...
What fault is caused by compression?
Compressional stress, meaning rocks pushing into each other, creates a reverse fault . In this type of fault, the hanging wall and footwall are pushed together, and the hanging wall moves upward along the fault relative to the footwall. This is literally the ‘reverse’ of a normal fault
Is a normal fault caused by compression or tension?
In terms of faulting, compressive stress produces reverse faults, tensional stress produces normal faults, and shear stress produces transform faults
What are the cause of normal fault?
Normal Faults: This is the most common type of fault. It forms when rock above an inclined fracture plane moves downward, sliding along the rock on the other side of the fracture . Normal faults are often found along divergent plate boundaries, such as under the ocean where new crust is forming.
What type of motion causes 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 extensional forces and results in extension . Other names: normal-slip fault, tensional fault or gravity fault. Examples: Sierra Nevada/Owens Valley; Basin & Range faults.
How do you identify a normal fault?
If the hanging wall drops relative to the footwall , you have a normal fault. Normal faults occur in areas undergoing extension (stretching). 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.
What happens to a road in a normal fault?
Normal faults occur in areas undergoing extension (stretching) . 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. If you stood on the fault plane, the block on the right would be under your feet.
What are the 3 kinds of faults?
Different types of faults include: normal (extensional) faults; reverse or thrust (compressional) faults ; and strike-slip (shearing) faults.
Which of the following is a normal fault?
normal fault – a dip-slip fault in which the block above the fault has moved downward relative to the block below. This type of faulting occurs in response to extension and is often observed in the Western United States Basin and Range Province and along oceanic ridge systems.
What kind of stress produces reverse faults?
A reverse fault is a dip-slip fault in which the hanging-wall has moved upward, over the footwall. Reverse faults are produced by compressional stresses in which the maximum principal stress is horizontal and the minimum stress is vertical.
What causes the fault to move?
A fault is formed in the Earth’s crust as a brittle response to stress . Generally, the movement of the tectonic plates provides the stress, and rocks at the surface break in response to this. ... If you whack a hand-sample-sized piece of rock with a hammer, the cracks and breakages you make are faults.
What are the three types of faults and its differences?
There are three different types of faults: Normal, Reverse, and Transcurrent (Strike-Slip) . Normal faults form when the hanging wall drops down. ... Reverse faults form when the hanging wall moves up. The forces creating reverse faults are compressional, pushing the sides together.
What does a reverse fault look like?
Reverse faults have sinuous traces and they are associated with half-cylindrical-shaped hills of the uplifted blocks due to drag folds deforming ancient planar erosion surface in the hanging wall.
Is a reverse fault vertical or horizontal?
In normal and reverse faulting, rock masses slip vertically past each other . In strike-slip faulting, the rocks slip past each other horizontally. Encyclopædia Britannica, Inc. A block that has dropped relatively downward between two normal faults dipping toward each other is called a graben.
What type of boundary is a normal fault?
Reverse faults occur at convergent plate boundaries, while normal faults occur at divergent plate boundaries . Earthquakes along strike-slip faults at transform plate boundaries generally do not cause tsunami because there is little or no vertical movement.
What happens to a river in a normal fault?
If a river is flowing toward the hanging wall, a normal fault could produce a waterfall because the hanging wall slides down along the footwall, so it is lower than the footwall. The water would cascade over the edge of the footwall and fall onto the hanging wall below.
