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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
Near the top of the formation is a thick layer of gypsum of very high quality. The whole rock is interrupted by gypsum veins as well as having a disrupted texture because of the precipitation of gypsum crystals after deposition of the rock. The Chugwater consists mainly of siltstone and shales with interspersed sandstones. While this ...
In an aeolian environment, cross-beds often exhibit inverse grading due to their deposition by grain flows. Winds blow sediment along the ground until they start to accumulate. The side that the accumulation occurs on is called the windward side. As it continues to build, some sediment falls over the end. This side is called the leeward side ...
The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone , sandstone , siltstone , and limestone and is light gray, greenish gray, or red.
The Carmel Formation consists of up to 1,000 feet (300 m) of mudrock and sandstone interbedded with limestone and gypsum. It was laid down in a shallow marine to sabkha environment, [1] into which terrigenous sediment was periodically carried. This gives the formation considerable lithological complexity. [3]
Below this is a gypsum mush where nodules of anhydrite and other sulfates may develop. These might also form a “chicken wire” crystalline structure. Below this are the intertidal deposits typified by laminated, organic-rich muds formed by the microbial mats that grade downward into more bioturbated muds.
Depositional environments may have included restricted marine bodies and ephemeral lakes (gypsum), hypersaline waters (limestone), hypersaline microbial mats (oil shale), and sabkhas (dolomite). The marine waters of the shallow continental sea retreated during the deposition of the formation, reflected in a change from dominantly nearshore ...