Depositional environment

Types of depositional environments

Continental

• Alluvial – Loose soil or sediment that is eroded and redeposited in a non-marine setting – type of Fluvial deposit. Caused by moving water in a fan shape (Alluvial Fan) and containing mostly impermeable and nonporous sediments well sorted.
• Aeolian – Processes due to wind activity. Often in deserts and coastal regions and well sorted, large scale cross-beds
• Fluvial – Natural flowing freshwater stream – processes due to moving water, mainly streams. Common sediments are gravel, sand, and silt.
• Lacustrine – Sediment deposited by a lake – processes due to moving water, mainly lakes. Common sediments are sand, silt, and clay.

Transitional

• Deltaic – Silt deposition landform at the mouth of a river (possible cross beds, ripple marks) Common sediments are sand, silt, and clay.
• Tide – Change in sea level due to gravity – processes due to tidal currents, creates tidal flats (fine-grained, ripple marks, cross-beds). Common sediments are silt and clay
• Lagoonal – Shallow body of water separated from a larger one by a narrow landform. Little transportation, creates lagoon bottom environment. Common sediments are carbonates (in tropical climates).
• Beach – Area of loose particles at the edge of a body of water. Caused by waves and longshore currents. Creates beaches, spits, and sandbars with the common sediments of gravel and sand.
• Lake – Large inland body of relatively still water

Marine

• Shallow water marine environment – Marine environment between the shore and the continental shelf – processes due to waves and tidal currents, creates shelves and slopes, lagoons. Common sediments are carbonates (in tropical climates) or sand, silt, and clay (elsewhere)
  • Upper shoreface – Maximum depth at which a water wave's passage causes significant water motion
  • Lower shoreface – Maximum depth at which a water wave's passage causes significant water motion
• Deep water marine environment – Flat area on the deep ocean floor (abyssal plains) caused by ocean currents. Common sediments are clay, carbonate mud, silica mud.
• Reef – Submerged ridge of rock, coral or other material caused by waves and tidal currents. Also creates adjacent basins. Common sediments are carbonates.

Others

• Evaporite – Water-soluble mineral deposit formed by evaporation from an aqueous solution
• Glacial – Persistent body of ice that moves downhill under its own weight
  • Till – angular to rounded grains, poorly sorted, unstratified (massive)
  • Outwash – ripple marks, cross-beds, similar to stream channel
• Volcanic – Rupture in a planet's crust where material escapes
• Tsunami – Sedimentary unit deposited by a tsunami