Continental rift

A region where continental lithosphere stretches and thins as tectonic plates move apart. Continued rifting can split a continent and develop into a new ocean basin.

Rift valley: An elongated depression formed where the crust subsides between faults during extension. Many continental rifts expose their extension in a central valley bounded by active faults.
East African Rift: An active continental rift system extending through eastern Africa. It shows ongoing extension within a continent before complete ocean-basin formation.
Pangaea: A supercontinent that assembled most of Earth's landmasses during the late Paleozoic and early Mesozoic. Its breakup began with rifting that opened the Atlantic Ocean.
Mid-ocean ridge: A submerged mountain chain where plates diverge and new oceanic crust forms. It is the mature oceanic spreading system that a successful continental rift can precede.
Normal fault: A fault in which the hanging wall moves downward relative to the footwall. Normal faults accommodate the crustal stretching that shapes many rift basins.
Baikal Rift Zone: A continental rift system surrounding Lake Baikal in southern Siberia. Its deep basin records extension far from an active ocean boundary.
Central Atlantic Magmatic Province: A vast, approximately 201-million-year-old igneous province formed across several continents. Its volcanism accompanied rifting during Pangaea's early breakup.
Subduction zone: A plate boundary where one tectonic plate descends beneath another. It consumes lithosphere, opposite to the extension and thinning characteristic of rifts.
Lithospheric stretching: Tectonic extension that lengthens and thins the lithosphere. It is the broad deformation that initiates continental rifting.
Rio Grande Rift: A north–south continental rift extending through the southwestern United States. It is a well-studied example of active extension within continental North America.

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