Deposition (geology)

Map of Cape Cod showing shores undergoing erosion (cliffed sections) in red, and shores characterized by marine deposition (barriers) in blue^[1]

Deposition is the geological process by which material is added to a landform or land mass. Fluids such as wind and water, as well as sediment flowing via gravity, transport previously eroded sediment, which, at the loss of enough kinetic energy in the fluid, is deposited, building up layers of sediment.

Deposition occurs when the forces responsible for sediment transportation are no longer sufficient to overcome the forces of particle weight and friction, creating a resistance to motion. Deposition can also refer to the buildup of sediment from organically derived matter or chemical processes. For example, chalk is made up partly of the microscopic calcium carbonate skeletons of marine plankton, the deposition of which has induced chemical processes (diagenesis) to deposit further calcium carbonate. Similarly, the formation of coal begins with deposition of organic material, mainly from plants, in anaerobic conditions.

See also

• Cementation
• Cross-bedding
• Diagenesis
• Overbank
• Sedimentary rock
• Sediment
• Sediment transport
• Sedimentary structures
• Geologists
  • Shen Kuo - 11th century Chinese scientist
  • Georgius Agricola - 16th century German sciences

References

1. ^ Oldale, Robert N.. "Coastal Erosion on Cape Cod: Some Questions and Answers". U.S. Geological Survey. http://woodshole.er.usgs.gov/staffpages/boldale/capecod/index.html. Retrieved 2009-09-11.