Accommodation
Aggradation
Aggradational
Boundaries
Falling Stage Systems Tract
Incised Valley
Lowstand Systems Tract
mfs
Progradation
Progradational Parasequence Set
Sequence
Stacking Patterns
Type-1 Sequence Boundary
Type-2 Sequence Boundary
Transgressive Systems Tract

The regressive deposits that form when sediment accumulation rates exceed the rate of relative sea-level rise and increase in accommodation constitutes the upper systems tract in either a type 1 or type 2 sequence.

The base of this systems tract is formed by the maximum flooding surface (mfs) over which the Highstand Systems Tract sediments prograde and agrade. The top of this systems tract is formed by the eroded unconformity surface that develops when a sea level fall initiates erosion of the now subaerial Highstand system sediment surface and the start of the Falling Stage Systems Tract.

This systems tract is commonly widespread on the shelf and may be characterized by one of more aggradation to progradational parasequence sets with prograding clinoform geometry. They onlap the sequence boundary in a landward direction and downlap the top of the Transgressive and/or Lowstand Systems Tracts in a basinward direction.