<P> The sediments underlying the tread and riser of a terrace are also commonly, but incorrectly, called terraces, leading to confusion . </P> <P> Terraces are formed in various ways . </P> <P> Fluvial terraces are remnants of the former floodplain of a stream or river . They are formed by the downcutting of a river or stream channel into and the abandonment and lateral erosion of its former floodplain . The downcutting, abandonment, and lateral erosion of a former floodplain can be the result of either changes in sea level, local or regional tectonic uplift; changes in local or regional climate; changes the amount of sediment being carried by the river or stream; change in discharge of the river; or a complex mixture of these and other factors . The most common sources of the variations in rivers and streams that create fluvial terraces are vegetative, geomorphic, and hydrologic responses to climate . More recently, the direct modification of rivers and streams and their watersheds by cultural processes have result in the development of terraces along many rivers and streams . </P> <P> Kame terraces are formed on the side of a glacial valley and are the deposits of meltwater streams flowing between the ice and the adjacent valley side . </P>

When do stream terraces form when do stream terraces form