What is "palaeochannel"

A palaeochannel or paleochannel is a remnant of an inactive river or stream channel that has been either filled or buried by younger sediment. The sediments that the ancient channel is either cut into or buried by can be either unconsolidated, semi-consolidated, consolidated, or lithified. The word palaeochannel is formed from the words "palaeo" or 'old', and channel; i.e.; a palaeochannel is an old channel. This may be synonymous with palaeovalley and palaeoriver.