1. A fan-shaped deposit formed by a stream either where it issues from a narrow moutain valley onto a plain or broad valley, or where a tributary stream joins a main stream. 2. A low, cone shaped deposit of terrestrial sediment formed where a stream undergoes an abrupt reduction of slope. 3. A fan-shaped wedge of sediment that typically accumulates on land where a stream emerges from a steep canyon onto a flat area. In map view it has the shape of an open fan. Typically forms in arid or semiarid climates.
Related terms: