Sequence stratigraphy aims to subdivide the sedimentary record into genetically related units separated by unconformities that represent pronounced temporal gaps. As many unconformities are erosional surfaces, incised valleys might be considered their prototypical expression. Five years ago, Strong and Paola utilized an experimental basin to examine the relation between morphodynamic and stratigraphic expressions of relative changes in sea level on a simulated fluvial-deltaic system. The results revealed complex interactions of erosion and deposition within this system that continuously modified the shape of incised valleys. The results suggested that these dynamics create “stratigraphic” valleys that never had physiographic expression in the fluvial landscape.
Valleys that Never Were: Time Surfaces VersusStratigraphic Surfaces, by Nikki Strong and Chris Paola, Journal of Sedimentary Research, v. 78, p. 579-593.