Outwash Fan

An outwash fan is a fan shaped body of sediment laid down by braided meltwater streams flowing away from a melting glacier. The sediment originates within the glacier itself, gathered through abrasion and plucking of the underlying rock, and is carried out by meltwater once the ice releases it, then spread across the fan by braided channels near the edge of the ice. Because the material has traveled only a short distance it is generally poorly sorted, though flowing water still separates it to some degree, leaving coarser pebbles closer to the ice and carrying finer silt and clay farther away. How quickly and how far an outwash fan grows depends on the glacier own rate of melting, making the landform a record of the glacier activity.