Brunette Girl Posing In The Sand

Sand is transported by wind and water and deposited in the form of beaches, dunes, sand spits, sand bars and related features. In environments such as gravel-bed rivers and glacial moraines it often occurs as one of the many grain sizes that are represented. Sand-bed rivers, such as the Platte River in Nebraska, USA, have sandy beds largely because there is no larger source material that they can transport. Dunes, on the other hand, are sandy because larger material is generally immobile in wind, and are a distinctive geographical feature of desert environments.
Study
The study of individual grains can reveal much historical information as to the origin and kind of transport of the grain. Quartz sand that is recently weathered from granite or gneiss quartz crystals will be angular. It is called grus in geology or sharp sand in the building trade where it is preferred for concrete, and in gardening where it is used as a soil amendment to loosen clay soils. Sand that is transported long distances by water or wind will be rounded, with characteristic abrasion patterns on the grain surface. Desert sand is typically rounded.