Alluvial

About

Alluvial refers to loose clay, silt, sand, or gravel that has been deposited by running water in various settings including stream beds, floodplains, alluvial fans, and beaches. The term derives from the Latin word alluvius, meaning "to wash against." Alluvium is also known as alluvial deposit and is typically geologically young, remaining unconsolidated rather than forming solid rock. Sediments deposited in underwater environments such as seas, estuaries, lakes, or ponds are not classified as alluvium. Floodplain alluvium is notably fertile and historically supported some of the earliest human civilizations.