Alluvium
From Encyclopedia Jr, free information reference for Kids
Alluvium (from the Latin, alluvius, from alluere, "to wash against") is soil or sediments deposited by a river or other running water. Alluvium is typically made up of a variety of materials, including fine particles of silt and clay and larger particles of sand and gravel.
Flowing water associated with glaciers may also deposit alluvium, but deposits directly from ice are not alluvium (see
A river is continually picking up and dropping solid particles of rock and soil from its bed throughout its length. Where the river flow is fast, more particles are picked up than dropped. Where the river flow is slow, more particles are dropped than picked up. Areas where more particles are dropped are called alluvial or
Even small streams make alluvial deposits, but it is in the
The amount of solid matter carried by a large river is enormous. The names of many rivers derive from the color that the transported matter gives the water. For example, the
Alluvium often contain valuable ores such as gold and platinum and a wide variety of gemstones. Such concentrations of valuable ores is termed a
Throughout history, many shallow lakes have been filled in with alluvium to leave