Silt is soil or rock derived granular material of a specific grain size. Silt may occur as a soil or alternatively as suspended sediment in a water column of any surface water body. It may also exist as deposition soil at the bottom of a water body. Silt is a type of soil or earth material. ... Loess field in Germany Surface-water-gley developed in glacial till, Northern Ireland Technically, soil forms the pedosphere: the interface between the lithosphere (rocky part of the planet) and the biosphere, atmosphere, and hydrosphere. ... “Rock” redirects here. ... A granular material is a conglomeration of discrete solid, macroscopic particles characterized by a loss of energy whenever the particles interact (the most common example would be friction when grains collide). ... Particle size, also called grain size, refers to the diameter of individual grains of sediment, or the lithified particles in clastic rocks. ... This article or section cites very few or no references or sources. ... A water column is a conceptual column of water from surface to bottom sediments. ...

Source

Silt is produced by the mechanical weathering of rock, as opposed to the chemical weathering that results in clays. This mechanical weathering can be due to grinding by glaciers, erosian abrasion (sandblasting by the wind) as well as water erosion of rocks on the beds of rivers and streams. Silt is sometimes known as 'rock flour' or 'stone dust', especially when produced by glacial action. Mineralogically, silt is composed mainly of quartz and feldspar. Sedimentary rock composed mainly of silt is known as siltstone. Weathering is the decomposition of rocks, soils and their minerals through direct contact with the air. ... A chemical substance is any material substance used in or obtained by a process in chemistry: A chemical compound is a substance consisting of two or more chemical elements that are chemically combined in fixed proportions. ... This article is about the geological formation. ... Glacially abraded rocks in western Norway near Jostedalsbreen glacier. ... Man sandblasting a stone wall Device used for adding sand to the compressed air (top of which is a sieve for adding the sand) Diesel powered compressor used as an air supply for sandbasting Sandblasting or bead blasting[1] is a generic term for the process of smoothing, shaping and... For morphological image processing operations, see Erosion (morphology). ... The bed of this stream is made up of rocks, some very rounded (having had a longer life in the stream) and some not. ... For other uses, see Quartz (disambiguation). ... This article does not cite any references or sources. ... Two types of sedimentary rock: limey shale overlaid by limestone. ... Siltstone Siltstone is a geological term for a sedimentary rock whose composition is intermediate in grain size between the coarser sandstone and the finer mudstone. ...

Silt, deposited by annual floods along the Nile River, created the rich and fertile soil that sustained the ancient Egyptian civilization. This silt was depended on for this purpose. A decrease in silt deposited by the Mississippi River throughout the 20th century has contributed to the disappearance of protective wetlands and barrier islands in the delta region surrounding New Orleans.[1] There is also Nile, a death metal band from South Carolina, USA. The Nile in Egypt Length 6 695 km Elevation of the source 1 134 m Average discharge 2 830 m³/s Area watershed 3 400 000 km² Origin Africa Mouth the Mediterranean Basin countries Uganda - Sudan - Egypt The... For the river in Canada, see Mississippi River (Ontario). ... (19th century - 20th century - 21st century - more centuries) Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s As a means of recording the passage of time, the 20th century was that century which lasted from 1901–2000 in the sense of the Gregorian calendar (1900–1999... A subtropical wetland in Florida, USA, with an endangered American Crocodile. ... In geography, a bar is a linear shoaling landform feature within a body of water. ... False-color image of the larger Mississippi Delta Closeup of the currently active delta front Mississippi Delta Lobes The Mississippi River Delta is the modern area of land (the river delta) built up by alluvium deposited by the Mississippi River as it slows down and enters the Gulf of Mexico. ... New Orleans is the largest city in the state of Louisiana, United States of America. ...

Grain size criteria

In the Udden-Wentworth scale (due to Krumbein), silt particles range between ¹⁄₂₅₆ and ¹⁄₁₆ mm (3.9 to 62.5 μm), larger than clay but smaller than a sand. In actuality, silt is chemically distinct from clay, and unlike clay, grains of silt are approximately the same size in all dimensions; furthermore, their size ranges overlap. According to the USDA Soil Texture Classification system, the sand-silt distinction is made at the 0.05 mm particle size.^[1] The USDA system has been adopted by the Food and Agriculture Organization (FAO). In the Unified Soil Classification System (USCS) and the AASHTO Soil Classification system, the sand-silt distinction is made at the 0.075 mm particle size (i.e. material passing the #200 sieve). Silts and clays are distinguished by their plasticity. Particle size, also called grain size, refers to the diameter of individual grains of sediment, or the lithified particles in clastic rocks. ... William Christian Krumbein (1902-1979) was a notable geologist, after whom the Krumbein Medal of the International Association for Mathematical Geology (IAMG) was named. ... For other uses, see Clay (disambiguation). ... For other uses, see Sand (disambiguation). ... “USDA” redirects here. ... The Food and Agriculture Organization of the United Nations (FAO) is a specialized agency of the United Nations that leads international efforts to defeat hunger. ... The Unified Soil Classification System (or USCS) is a soil classification system used in engineering and geology disciplines to describe the texture and grain size of a soil. ... This page is a candidate to be moved to Wiktionary. ... In general, a sieve separates wanted/desired elements from unwanted material using a tool such as a mesh, net or other filtration or distillation methods. ... For other uses, see Plasticity. ...

Silt deposits around house and car in New Orleans left by flooding from a breach in the London Avenue Canal

Image File history File linksMetadata Download high-resolution version (2592x1944, 1835 KB) New Orleans after Hurricane Katrina: Residential neighborhood a few blocks from the lower breach of the London Avenue Canal; flooding left house and automobile deep in silt. ... Image File history File linksMetadata Download high-resolution version (2592x1944, 1835 KB) New Orleans after Hurricane Katrina: Residential neighborhood a few blocks from the lower breach of the London Avenue Canal; flooding left house and automobile deep in silt. ... New Orleans is the largest city in the state of Louisiana, United States of America. ... The London Avenue Canal in New Orleans, Louisiana does not connect Lake Pontchartrain to the Mississippi River. ...

Environmental impacts

Silt can occur as a deposit or as material transported by a stream or by a current in the ocean. Silt is easily transported in water and is fine enough to be carried long distances by air as 'dust'. Thick deposits of silty material resulting from aeolian deposition are often called loess (a German term) or limon (French). Silt and clay contribute to turbidity in water. Butchers Creek, Omeo, Victoria A stream, brook, beck, burn or creek, is a body of water with a detectable current, confined within a bed and banks. ... A current is a movement or flow of fluids, especially water in a river or ocean. ... Animated map exhibiting the worlds oceanic waters. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... Look up dust in Wiktionary, the free dictionary. ... This article or section does not cite any references or sources. ... Turbidity standards of 5, 50, and 500 NTU Turbidity is a cloudiness or haziness of a fluid caused by individual particles (suspended solids) that are generally invisible to the naked eye, similar to smoke in air. ...

One of the main causes of river siltation in the year 2006 is the result of slash and burn treatment of tropical forests. When the total ground surface is stripped of vegetation and then seared of all living organisms, the upper soils are vulnerable to both wind and water erosion. In a number of regions of the earth, entire sectors of a country have been rendered unproductive; for example, on the Madagascar high central plateau, comprising approximately ten percent of that country's land area, virtually the entire landscape is sterile of vegetation, with gully erosive furrows typically in excess of 50 meters deep and one kilometer wide. Shifting cultivation is a farming system which sometimes incorporates the slash and burn method in some regions of the world. The resulting sediment load in rivers flowing to the west is ongoing, with most rivers a dark red brown colour. The resulting fish kills in most of these rivers have resulted in the process of extinction of a variety of Madagascar's fish species. Assarting in Finland in 1892 Slash and burn (a specific practice that may be part of shifting cultivation or swidden-fallow agriculture) is an agricultural procedure widely used in forested areas. ... The tropics are the geographic region of the Earth centered on the equator and limited in latitude by the two tropics: the Tropic of Cancer in the north and the Tropic of Capricorn in the southern hemisphere. ... This article is about a community of trees. ... For other uses, see Plateau (disambiguation). ... Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants, and is, by far, the most abundant biotic element of the biosphere. ... Shifting cultivation is an agricultural system in which plots of land are cultivated temporarily, then abandoned. ... Assarting in Finland in 1892 Slash and burn (a specific practice that may be part of shifting cultivation or swidden-fallow agriculture) is an agricultural procedure widely used in forested areas. ... For other uses, see Species (disambiguation). ...

See also

• Particle size
• Sediment

Particle size, also called grain size, refers to the diameter of individual grains of sediment, or the lithified particles in clastic rocks. ... This article or section cites very few or no references or sources. ...

References

1. ^ Particle Size (618.43). National Soil Survey Handbook Part 618 (42-55) Soil Properties and Qualities. United States Department of Agriculture - Natural Resource Conservation Service. Retrieved on 2006-05-31.