Floodplain sedimentation: inherited memories

Swampy inherited floodplains are found throughout the steppe and forest steppe over the Russian Plain. These floodplains were formed during the Late Glacial/Holocene transition on the relicts of large meandering palaeochannels in the former periglacial zone as a result of dramatic decrease in river channel widths (up to 1/15). Inherited floodplains were only partly reworked by the activity of the Holocene rivers. The remnants of the ancient fluvial relief control the flow hydraulics and sediment transport delivery to the river channels on the wide floodplains, causing sediment discontinuity. Such discontinuity reaches its maximum in the chain-of-lakes channels, and decreases with the evolution of the inherited floodplain into a typical floodplain with developed continuous channels.