A rift zone is a feature of some volcanoes, especially the shield volcanoes of Hawaii, in which a linear series of fissures in the volcanic edifice allows lava to be erupted from the volcano's flank instead of from its summit. For example, in the currently ongoing eruption of Kilauea lava is emitted continuously from the Puʻu ʻŌʻō vent located in Kilauea's East Rift Zone roughly 15 km east of Kilauea Crater. Rift zones tend to extend for tens of kilometers radially outward from the volcanic summit; most Hawaiian volcanoes have two or sometimes three of them. The accumulated lava of repeated eruptions from rift zones causes many Hawaiian volcanoes to have an elongated shape. Perhaps the best example of this is Mauna Loa, which in Hawaiian means "long mountain".

The origin of the fractures that comprise the rift zones is spreading of the volcano. The more material a shield volcano accumulates, the heavier it gets, and it begins to settle due to the simple effects of gravity. The surface spreads and ruptures.

In geology, a rift or chasm 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 downfaulted 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.

Major rifts occur along the central axis of mid-ocean ridges, where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates.

Failed rifts are where continental rifting began, but then failed to continue to the point of break-up. Typically the transition from rifting to spreading develops at a triple junction where three converging rifts meet over a hotspot. Two of these evolve to the point of seafloor spreading, while the third ultimately fails, becoming an aulacogen.

Zone may refer to: