Deposition of Eroded Sediments

What is deposition? Deposition is the laying down of weathered and eroded sediments (bits and pieces of larger rock masses). Most deposition occurs in bodies of water.

Factors which affect deposition: Particle size As particle size increases the rate of deposition (how fast the particles fall to the bottom of a column of water) also increases. Settling rate Particle size

Particle shape... Smooth rounded particles will settle out more quickly than flatter more irregularly shaped particles.

Particle density... Denser particles will fall faster than less dense particles of similar size and shape. Settling rate Particle density

Stream velocity…(see page 6 of Reference Tables) Stream velocity generates kinetic energy. The faster a stream is flowing, the more energy it has. As stream velocity increases, the volume and size of sediments being carried also increases. Volume and particle size Velocity of stream

Likewise, as streamvelocity decreases, the settling rate increases. Incoming stream with sediments Coarse gravel Finer sand Finer silt Finest clay

Major stream deposits Deltas - triangular fan shaped deposits that develop as a stream or river flows into a larger body of water. Alluvial Fans - Similarly shaped deposits which develop as a stream from a mountain flows out onto flat land, thus losing kinetic energy and depositing its sediment load.