Förkastningsplan

Förkastningsplan is a geological term referring to the surface along which a rock mass has moved relative to another rock mass due to faulting. It is the boundary between the hanging wall and the footwall in a fault. The hanging wall is the block of rock that lies above the fault plane, while the footwall is the block of rock that lies below it. The movement along a förkastningsplan can be in various directions, leading to different types of faults such as normal faults, reverse faults, and strike-slip faults.

The orientation and characteristics of a förkastningsplan provide crucial information about the stresses and tectonic forces acting on a region. For instance, a steeply dipping förkastningsplan is often associated with compressional forces, while a gently dipping one might indicate extensional forces. The surface of a förkastningsplan can exhibit slickensides, which are polished and grooved surfaces created by the friction of rock masses sliding against each other. These features can indicate the direction and sense of movement.

Understanding förkastningsplan is fundamental in fields like structural geology, earthquake seismology, and resource exploration. Their presence and geometry influence the landscape, can create traps for hydrocarbons or mineral deposits, and are the direct cause of seismic activity when stresses build up and are suddenly released along them. Mapping and analyzing förkastningsplan are essential for assessing geological hazards and understanding the Earth's crustal deformation processes.