Contrast 2 types of depositional Environments: In geology, the depositional environment or sedimentary environment refers to the combination of physical, chemical, and biological processes associated with the deposition of a specific type of sediment and, consequently, the rock types that will form after lithification if the sediment is preserved in the rock record.
The environments associated with specific rock types or associations of rock types can usually be matched to existing analogues.
Contrast 2 types of depositional Environments.
Continental
- Alluvial – 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 – processes due to moving water, mainly streams. Common sediments are gravel, sand, and silt.
- Lacustrine – 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 – Rise and fall of the sea level under astronomical gravitational influences – 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 body of water 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 the sea or other body of water. Caused by waves and longshore currents. Creates beaches, spits, and sandbars with the common sediments of gravel and sand.
- Lake – Large body of relatively still water
Marine
- Shallow water marine environment – 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 – Portion of the seafloor that is shallow enough to be agitated by everyday wave action
- Lower shoreface – Portion of the seafloor, and the sedimentary depositional environment, that lies below the everyday wave base
- 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 – A shoal of rock, coral or other sufficiently coherent material, lying beneath the surface of water 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
- Till – angular to rounded grains, poorly sorted, unstratified (massive)
- Outwash – ripple marks, cross-beds, similar to stream channel
- Volcanic
- Tsunami – Sedimentary unit deposited by a tsunami
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