<P> Parent material is classified by its last means of transport . Material that was transported to a location by glacier, then deposited elsewhere by streams, is classified as stream - transported parent material, or glacial fluvial parent material . </P> <P> Glacial till is material dragged with a moving ice sheet . Because it is not transported with liquid water, the material is not sorted by size . </P> <P> Within water transported parent material there are several important types . </P> <P> Parent material transported by streams is called alluvium of which there are three main types . Floodplains are the parts of river valleys that are covered with water during floods . Due to their seasonal nature, floods create stratified layers in which larger particles tend to settle nearer the channel and smaller particles settle nearer the edges of the flooding area . Alluvial fans are sedimentary areas formed by narrow valley streams that suddenly drop to lowlands and widen dramatically . Sedimentary in these types of deposits tend to be larger closer to the uplands and finer near the edges of the fan . Delta deposits, the third of type of alluvium, are finer sediments that are discharged from streams into lakes and eventually settle near the mouth of the river . </P>

The parent material layer of soil is composed of weathered