külgdislokatsioon

Külgdislokatsioon refers to a geological fault where the movement between the two sides of the fault is predominantly horizontal. This type of fault is also known as a strike-slip fault. The movement occurs parallel to the strike of the fault line, meaning the rock masses slide past each other horizontally.

There are two primary types of strike-slip faults: dextral (right-lateral) and sinistral (left-lateral). In a dextral strike-slip fault, if an observer stands on one side of the fault and looks across to the other side, the opposite block appears to have moved to the right. Conversely, in a sinistral strike-slip fault, the opposite block appears to have moved to the left.

Strike-slip faults are often associated with transform plate boundaries, where tectonic plates slide past each other. The San Andreas Fault in California is a famous example of a dextral strike-slip fault. These faults can be responsible for significant earthquakes due to the friction that builds up as the rock masses are forced to move past one another. The energy released during these movements can cause seismic waves.

Geologists identify strike-slip faults through various geological features, including offset streams, linear valleys, scarps, and the alignment of geological formations across the fault trace. The absence of significant vertical displacement is a key characteristic distinguishing them from dip-slip faults, which involve primarily vertical movement. Understanding the type and direction of movement along strike-slip faults is crucial for seismic hazard assessment and geological mapping.