What Types Of Materials Do Glaciers Deposit?
Glaciers are very effective at rearranging earth materials. Rocks ranging in size from the finest powder to boxcar-sized boulders have been eroded, transported, and deposited by glaciers. Even larger slabs of rock, up to 1 mile (1.6 km) in length, can be shown to have moved under the influence of glaciers. Sediment is released from the ice when the glacier melts. A variety of sediment types are deposited by, or are the result of, glaciers. Till is the term used to describe unsorted glacial sediment. In South Dakota, tills contain a large amount of clay- and silt-sized particles (roughly 65 percent by weight), as well as sand and scattered larger rock fragments. When water from melting ice interacts with the sediment, a number of “sorted” sediments result. Sand and gravel deposits (outwash ) result when meltwater removes finer silts and clays. Fine-grained sediments are deposited when meltwater becomes ponded in lakes or slower moving sections of meltwater streams. Loess is the term use
