Editing Retrogradation (section)

{{short description|Movement of the front of a river delta inland over time}}
{{About|the geological term related to [[river delta]]s|other uses|Retrograde (disambiguation)}}

'''Retrogradation''' is the landward change in position of the front of a [[river delta]] with time. This occurs when the [[mass balance]] of sediment into the delta is such that the [[volume]] of incoming [[sediment]] is less than the volume of the delta that is lost through [[subsidence]], [[sea-level rise]], and/or [[erosion]]. As a result, retrogradation is most common:
*during periods of [[sea-level rise]] which results in [[marine transgression]]. This can occur during major periods of [[global warming]] and the melting of continental [[ice sheets]].
*with extremely low sediment input.