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A diagram of various depositional environments. In geology, depositional environment or sedimentary environment describes the combination of physical, chemical, and biological processes associated with the deposition of a particular type of sediment and, therefore, the rock types that will be formed after lithification, if the sediment is preserved in the rock record.
Evaporite depositional environments that meet the above conditions include: Graben areas and half-grabens within continental rift environments fed by limited riverine drainage, usually in subtropical or tropical environments Example environments at the present that match this is the Denakil Depression, Ethiopia; Death Valley, California
Normally graded beds generally represent depositional environments which decrease in transport energy (rate of flow) as time passes, but these beds can also form during rapid depositional events. They are perhaps best represented in turbidite strata , where they indicate a sudden strong current that deposits heavy, coarse sediments first, with ...
There are a few distinctly different channel types based on their geological structure and depositional environment. Braided rivers carry fairly coarse-grained sediment down a fairly steep gradient. They typically exhibit numerous channels that split off and rejoin each other to give a braided appearance.
Concretion rock with white core from the Middle Jurassic of Iran. Detailed studies have demonstrated that concretions form after sediments are buried but before the sediment is fully lithified during diagenesis.
Robert J. Dunham published his classification system for limestone in 1962. [2] The original Dunham classification system was developed in order to provide convenient depositional-texture based class names that focus attention on the textural properties that are most significant for interpreting the depositional environment of the rocks.
These structures are within sedimentary bedding and can help with the interpretation of depositional environment and paleocurrent directions. They are formed when the sediment is deposited. Cross-bedding Cross-bedding is the layering of beds deposited by wind or water inclined at an angle as much as 35° from the horizontal. [1]
Walther's law of facies, or simply Walther's law, named after the geologist Johannes Walther, states that the vertical succession of facies reflects lateral changes in environment. Conversely, it states that when a depositional environment "migrates" laterally, sediments of one depositional environment come to lie on top of another. [ 4 ]