Definition - What does Outwash mean?
Outwash is the deposit of gravel and sand carried by running water from melting ice at the terminus of a glacier. The gravel and sand are laid down in the stratified deposits found in glaciated areas. The icecaps and glaciers consist of silt and a large amount of sediments which are carried when they erode the underlying rocks while moving slowly downhill. At the snout of a glacier, the melting water carries sediment away from the glacier and accumulates it on a broad plain.
Petropedia explains Outwash
Outwash is also known as sandar, sandr. It is a plain that is formed by the glacial sediment accumulated by the melt-water Outwash at glaciers. A thickness of around 100 meters can be attained by the Outwash at the edge of the glaciers which can extend many kilometers in length. The sheet of the Outwash can be dissected by the postglacial streams or pitted with the undrained kettles. These plains are generally cross-bedded with the units of changing grain size. When they are confined or limited within the walls of a valley, the deposit is known as a valley train.