Saint Anthony Falls Laboratory Research Articles

Fluvial Landscapes and Stratigraphy in a Flume

We use data from an experiment conducted in the Experimental EarthScape (XES) facility, National Center for Earth-surface Dynamics (NCED), St.Anthony Falls Laboratory (SAFL), University of Minnesota, to demonstrate why incised valleys preserved in the stratigraphic record probably bear little resemblance to the actual valleys as they appeared in the paleolandscape. In an experiment designed to study fluvial response to changes in sea level,we find that preserved incised-valley structures are typically broader and have more gentle side slopes, than the topographic features from which they develop. Also, because of widening driven by valley wall erosion during both relative sea-level rise and fall, there is virtually no remnant of terraces formed during falling relative sea level preserved in the stratigraphic record.The process of filling an incised valley due to rising relative sea level is not a passive depositional process that simply buries and preserves the original shape of the valley; rather, it includes an energetic erosional component that substantially reshapes the original valley form.