Terrace deposit
A
river terrace is
geological term for a flat platform of land created on either side of a
river where, at some time in the past, the river has cut itself a deeper channel. The former
floodplain of the river is therefore at a higher point and is known as a terrace. Rivers can create a sequence of terraces over millennia as they erode away more material.
Terraces are formed during
river rejuvenation, when the river gains in
gravitational potential energy. The terraces themselves are often made from fluvial material previously dumped by the river to create the earlier floodplain, These terrace deposits are broadly horizontal layers of
gravel,
sand and finer sediments that can sometimes contain
prehistoric archaeological finds.
Another notable source of stream terracing is the agradation of legacy sediments behind dams. These sediment deposits can accumulate very radidly, in under 300 years, and can be observed to be in excess of 5m in height.
River Terrace is also a neighborhood in Washington, D.C. Thhis is the only neighborhood in the District of Columbia in which there is no connection to another neighbohood.
