lowstand systems tract

views updated

lowstand systems tract (LST) In the genetic stratigraphic sequence model used in sequence stratigraphy, a bounding surface formed either from allochthonous deposits eroded from the platform margin and slope, or from autochthonous wedges deposited on the upper slope. See SYSTEMS TRACT. Compare HIGHSTAND SYSTEMS TRACT; and TRANSGRESSIVE SYSTEMS TRACT. See also REGRESSIVE SYSTEMS TRACT.