ABSTRACT
The term ‘‘alluvial fan’’ is used in both geomorphology and geology. An alluvial fan in the geomorphological sense is a semiconical depositional landform produced by fluvial and/or debris-flow processes. Fans have concave-up to straight long profiles but convex-up cross profiles. A body of deposits forming such a landform is also called an alluvial fan. Deltas and delta deposits may also have semiconical shapes but are mainly produced by marine processes and so are not alluvial fans. When alluvial fans enter a standing water body, they are described as fan deltas.
