Outwash Plain
When the farthest ends of a glacier melt and the glacier begins to recede, meltwater floods the valley below. Meltwater contains gravel, sand, and fine silt. When this sediment is deposited by meltwater carried away from glacier, it is called outwash. Because of the way water transports sediment, outwash is always sorted by particle size. The area at the leading edge at the leading edge of the glacier where meltwater flows and deposits outwash is called an outwash plain.
This outwash plain is at the terminus of Peyto Glacier in Banff National Park, Canada. This happens when glaciers release a great deal of water as they melt, usually in streams that exit from the snout carrying large quantities of fresh-ground rock. When the ground is relatively flat, the sediment builds up in an outwash plain and the meltwater streams wander over it in a braided pattern, helpless to dig into the sedimentary abundance.