Rift Valley:a large elongated depression with steep walls formed by the downward displacement of a block of the earth's surface between nearly parallel faults or fault systems.
mid-oceanic ridge:A mid-ocean ridge is a general term for an underwater mountain system that consists of various mountain ranges (chains), typically having a valley known as a rift running along its spine, formed by plate tectonics
Subduction Zone: A subduction zone is the biggest smash-up on Earth, marking the collision between two of the planet's tectonic plates, the pieces of crust that slowly move across the surface over millions of years. When two tectonic plates meet, one may slide underneath the other, curving down into the mantle.:
Orogenesis: Orogeny refers to forces and events leading to a large structural deformation of the Earth's lithosphere due to the engagement of tectonic plates. Response to such engagement results in the formation of long tracts of highly deformed rock called orogens or orogenic belts.
continental volcanic arc: oceanic arcs form when oceanic crust subducts beneath other oceanic crust on an adjacent plate, creating a volcanic island arc. (Not all island arcs are volcanic island arcs.) continental arcs form when oceanic crust subducts beneath continental crust on an adjacent plate, creating an arc-shaped mountain belt.
Volcanic Island Arc: Offshore volcanoes form islands, resulting in a volcanic island arc. Generally they result from the subduction of an oceanic tectonic plate under another tectonic plate, and often parallel an oceanic trench