1. n. [Geology]

The accumulation of sequences by deposition in which beds are deposited successively landward because sediment supply is limited and cannot fill the available accommodation. Thus, the position of the shoreline migrates backward onto land, a process called transgression, during episodes of retrogradation.

Antonyms: progradation

See: accommodation,  bed,  onlap,  sequence,  sequence stratigraphy,  transgression