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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.
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.
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 ...
Lacustrine deposits have gained more attention recently due to containing valuable source rocks of oil, coal, and uranium. Lacustrine deposits generally provide productive mining conditions but can prove challenging when underground mines are attempted due to the poor shear strength of clays and silts as well as the amount of moisture often locked in the layers due to a low permeability ...
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]
SEDEX deposits belong to the large class of non-magmatic hydrothermal ore deposits formed by basinal brines. [11] This class includes also: Mississippi valley type (MVT) zinc-lead deposits. [8] Sediment-hosted stratiform Cu-Co-(Ag) deposit, typified by the Copperbelt of Zambia and DRC. [12]
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
Mudrocks are a class of fine-grained siliciclastic sedimentary rocks. The varying types of mudrocks include siltstone , claystone , mudstone and shale . Most of the particles of which the stone is composed are less than 1 ⁄ 16 mm (0.0625 mm; 0.00246 in) and are too small to study readily in the field.