Aggradation

Aggradation 

Vertical build up of a sedimentary sequence. Usually occurs when there is a relative rise in sea level produced by subsidence and/or eustatic sea-level rise, and the rate of sediment influx is sufficient to maintain the depositional surface at or near sea level (i.e. carbonate keep-up in a HST [highstand Systems Tract] or clastic HST). Occurs when sediment flux = rate of sea-level rise. Produces Aggradational stacking patterns in parasequences when the patterns of facies at the top of each parasequence are essentially the same (Posamentier, 1999; Wilgus et al.; 1988, Emery, 1996).