Also known as fluted moraine, these are elongate streamlined ridges of sediment that are produced beneath a glacier and which are aligned in the direction of ice flow.
They are the smallest landform type in the family of subglacial bedforms, and typically occur as numerous parallel ridges, tens of centimetres to a few metres high and wide, and tens of metres in length.
These rather delicate landforms are best observed close to recently retreated glacier margins, and due to their poor preservation potential are much less commonly found in relation to former ice sheets.
Benn, D.I., and Evans, D.J.A., 1998: Glaciers and Glaciation. London: Arnold.