In geology, a rift is a place where the Earth's crust and lithosphere are being pulled apart and is an example of extensional tectonics.
Typical rift features are a central linear downdropped fault segment, called a graben, with parallel normal faulting and rift-flank uplifts on either side forming a rift valley, where the rift remains above sea level. The axis of the rift area commonly contains volcanic rocks and active volcanism is a part of many, but not all active rift systems.
Most rifts occur along the central axis of a mid-ocean ridge, where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates.
