Silt is a fine-grained or muddy material made up of tiny particles of rock that settle at the bottom of rivers and other bodies of water. A material which sinks in water or air is known as sediment. Common examples of sediment are clay, silt, sand, and gravel. Silt is made up of particles ranging from 0.004 to 0.0625 millimeter (1/6,500 to 1/400 inch) in diameter. Most lands with silt deposits are fertile.
