Silt is soil or rock derived granular material of a specific grain size. Soil, often typeset as SOiL, is a four piece rock band from Chicago Illinois United States founded by Shaun Glass Tom Schofield Tim King and Adam Zadel In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere 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 Particle size, also called grain size, refers to the Diameter of individual grains of Sediment, or the lithified particles in Clastic Silt may occur as a soil or alternatively as suspended sediment in a water column of any surface water body. Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of A water column is a conceptual column of water from surface to bottom sediments A body of water is any significant accumulation of Water, usually covering the Earth or another planet It may also exist as deposition soil at the bottom of a water body.

Source

Silt is generated by a variety of modi capable of breaking and splitting up generally sand-sized quartz crystals of primary rocks by exploiting deficiencies in their lattice^[1]. In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. These involve chemical weathering of rock^[2] and regolith, and a number of physical weathering processes such as frost shattering^[3] and haloclasty^[4]. Weathering is the decomposition of earth rocks, Soils and their Minerals through direct contact with the planet's Atmosphere. Regolith ( Greek: "blanket rock" is a layer of loose Heterogeneous material covering solid rock. Weathering is the decomposition of earth rocks, Soils and their Minerals through direct contact with the planet's Atmosphere. Haloclasty is a type of physical weathering caused by the growth of Salt crystals. However, it is mainly by abrasion through transport-processes such as fluvial comminution, aeolian attrition and glacial grinding ^[5] most effectively operating in semi-arid environments ^[6] that substantial quantities of silt are produced. Abrasion is mechanical scraping of a rock surface by Friction between rocks and moving particles during their transport in Wind, Glacier, Waves Fluvial is used in Geography and Earth science to refer to the deposits and landforms created by the action of rivers or streams and the processes associated with Comminution is one of the four main groups of mechanical processing and describes the movement of the Particle size distribution (grains drops bubbles into a range of finer Attrition is a form of coastal or river Erosion, when the bed load is eroded by itself "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. 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. Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in Feldspar is the name of a group of rock-forming Minerals which make up as much as 60% of the Earth 's crust. Sedimentary rock composed mainly of silt is known as siltstone. Sedimentary rock is one of the three main rock types (the others being igneous and Metamorphic rock) Siltstone is a Sedimentary rock which has a composition intermediate in grain size between the coarser Sandstones and the finer Mudstones and

Grain size criteria

In the Udden-Wentworth scale (due to Krumbein), silt particles range between ¹⁄₂₅₆ and ¹⁄₁₆ mm (3. William Christian Krumbein (1902-1979 was a notable geologist after whom the Krumbein Medal of the International Association for Mathematical Geology (IAMG was named 9 to 62. 5 μm), larger than clay but smaller than a sand. Clay is a naturally occurring material composed primarily of fine-grained Minerals which show plasticity through a variable range of Water content, and Sand is a naturally occurring Granular material composed of finely divided rock and Mineral particles ISO 14688 grades silts between 0. 002 mm and 0. 063 mm, with clay particles being smaller and sands larger. 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. Clays are formed from thin plate-shaped particles held together by electrostatic forces, so present a cohesion. According to the USDA Soil Texture Classification system, the sand-silt distinction is made at the 0. 05 mm particle size. ^[7] 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. The Unified Soil Classification System (or USCS) is a Soil classification system used in Engineering and Geology disciplines to describe the AASHTO, the American Association of State Highway and Transportation Officials, is a standards setting body which publishes specifications test protocols and 075 mm particle size (i. e. material passing the #200 sieve). Silts and clays are distinguished by their plasticity.

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

Environmental impacts

Silt can occur as a deposit or as material transported by a stream or by a current in the ocean. New Orleans (nʲuːˈɔrliənz nʲuːˈɔrlənz French: La Nouvelle-Orléans) is a major United States port city and the largest city in Louisiana The London Avenue Canal is a drainage Canal in New Orleans Louisiana, used for pumping rain water into Lake Pontchartrain. A stream is a body of Water with a current, confined within a bed and stream-banks A current, in a River or Stream, is the Flow of Water influenced by Gravity as the water moves Downhill to reduce its An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere. Silt is easily transported in water and is fine enough to be carried long distances by air as 'dust'. Water is a common Chemical substance that is essential for the survival of all known forms of Life. Dust is a general name for minute Solid particles with Diameters less than 500 micrometers. Thick deposits of silty material resulting from aeolian deposition are often called loess (a German term) or limon (French). Loess is a homogeneous typically non stratified porous Friable,slightly coherent often calcareous fine-grained Silty pale yellow or buff windblown ( aeolian Silt and clay contribute to turbidity in water. Turbidity is the cloudiness or haziness of a fluid caused by individual particles ( suspended solids) that are generally invisible to the Naked eye

The main source of river siltation and storm sewer sedimentation in urban areas is disturbance of soil by construction activity. The main cause of river siltation in rural areas is erosion from extensive plowing of farm fields, clearcut logging or slash and burn treatment of forests. Erosion is the carrying away or displacement of solids ( Sediment, Soil, rock and other particles usually by the agents of currents such as wind Slash and burn consists of cutting and burning of Forests or Woodlands to create fields for Agriculture or Pasture for Livestock, or A forest is an area with a high density of Trees There are many definitions of a forest based on various criteria When the total ground surface is stripped of vegetation, 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. Madagascar, or Republic of Madagascar (older name Malagasy Republic) is an Island nation in the Indian Ocean off the southeastern In Geology and Earth science, a plateau, also called a high plateau or tableland, is an area of highland, usually consisting Vegetation is a general term for the plant life of a region it refers to the Ground cover provided by plants Shifting cultivation is a farming system which sometimes incorporates the slash and burn method in some regions of the world. For methods see Slash and burn Shifting cultivation is an Agricultural system in which plots of land are cultivated temporarily then abandoned Slash and burn consists of cutting and burning of Forests or Woodlands to create fields for Agriculture or Pasture for Livestock, or The resulting sediment load can cause extensive fish kills, hampering economic development.

Silt, deposited by annual floods along the Nile River, created the rich and fertile soil that sustained the ancient Egyptian civilization. The Nile (النيل, Ancient Egyptian iteru or Ḥ'pī, Coptic piaro or phiaro) is a major north-flowing River Ancient Egypt was an Ancient Civilization in eastern North Africa, concentrated along the lower reaches of the Nile River in what is now This silt was depended on for this purpose. A decrease in silt deposited by the Mississippi River throughout the 20th century due to a system of levees has contributed to the disappearance of protective wetlands and barrier islands in the delta region surrounding New Orleans. The Mississippi River is the second longest River in the United States, with a length of from its source in Lake Itasca in Minnesota to The twentieth century of the Common Era began on Dike (constructionEmbankmentA levee, levée, dike (or dyke) embankment, floodbank or stopbank is a natural or artificial A wetland is an area of Land consisting of Soil that is Saturated with Moisture, such as a Swamp, Marsh, or Bog A shoal or sandbar (also called sandbank) is a somewhat Linear Landform within or extending into a body of Water, 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 New Orleans (nʲuːˈɔrliənz nʲuːˈɔrlənz French: La Nouvelle-Orléans) is a major United States port city and the largest city in Louisiana [1]

References

1. ^ Moss, A J; Green, P (1975). "Sand and silt grains: Predetermination of their formation and properties by microfractures in quartz". Australian Journal of Earth Sciences 22 (4): 485-495.  
2. ^ Nahon, D; Trompette, R (1982). "Origin of siltstones:glacial grinding versus weathering". Sedimentology 29: 25-35.  
3. ^ Lautridou, J P; Ozouf, J C (1982). "Experimental frost shattering: 15 years of research at the Centre de Geomorphologie du CNRS". Progress in Physical Geography 6: 215-232.  
4. ^ Goudie, A S; Viles, H A (1995). "The nature and pattern of debris liberated by salt weathering: a laboratory study". Earth Surface Processes and Landforms 9: 95-98.  
5. ^ Wright, J S; Smith, B J; Whalley W B (1998). "Mechanisms of loess-sized quartz silt production and their relative effectiveness: laboratory simulations". Geomorphology 23: 15-34.  
6. ^ Haberlah, D (2007). "A call for Australian loess". AREA 39 (2): 224-229.  
7. ^ 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. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1279 BC - Rameses II (The Great (19th dynasty becomes pharaoh of Ancient Egypt.