A landform composed of sediments brought by a river and found where it enters a main valley or emerges from a mountain on to a plain is called a/an

A landform composed of sediments brought by a river and found where it enters a main valley or emerges from a mountain on to a plain is called an Alluvial fan. An alluvial fan is a triangle-shaped deposit of gravel, sand, and even smaller pieces of sediment, such as silt. This sediment is called alluvium. Alluvial fans are usually created as flowing water interacts with mountains, hills, or the steep walls of canyons.