River Response to Baselevel Change: Implications for Sequence Stratigraphy

TLDR

Baselevel, defined as the sea‑level surface to which sub‑aerial erosion proceeds, influences river behavior, landscape rejuvenation, and sediment delivery, but its effects are generally moderate and depend on change rate, magnitude, direction, river character, and sediment source dynamics. The study finds that large sediment deliveries to shorelines or continental shelves likely result from a combination of baselevel lowering, significant uplift of sediment‑source areas, and possibly climate change.

Abstract

Baselevel is the imaginary horizontal level or surface to which sub-aerial erosion proceeds. It is sea level. Controversy surrounds the effect of baselevel change on river behavior, the rejuvenation of landscapes, and the delivery of sediment to the shelf-slope depositional system. The effect of baselevel change depends upon many factors, such as rate of change, amount of change, direction of change, river character, and dynamics and erodibility of the sediment source area. In most cases the effects of baselevel change will be moderate, and they can be accommodated by changes of channel pattern, width, depth, and roughness. Therefore, the delivery of large amounts of sediment to a shoreline or continental shelf probably reflects not only baselevel lowering, but significant uplift of the sediment-source area and perhaps climate change.