Rifted continental margins are formed by progressive extension of the lithosphere. The development of these margins plays an integral role in the plate tectonic cycle, and an understanding of the extensional process underpins much hydrocarbon exploration.
A key issue is whether the lithosphere extends uniformly, or whether extension varies with depth. Crustal extension may be determined using seismic techniques. Lithospheric extension may be inferred from the waterloaded subsidence history, determined from the pattern of sedimentation during and after rifting. Unfortunately, however, many rifted margins are sediment-starved, so the subsidence history is poorly known.