In USA soil taxonomy, Entisols are defined as soils that do not show any profile development. An Entisol can have no A horizon or B horizon, and most are basically unaltered from their parent rock. Soil taxonomy provided by United States Department of Agriculture / Natural Resources Conservation Centre provides an elaborate classification of soil types according to several parameters and in several levels: Order, Suborder, Great Group, Subgroup, Family, and Series. ... The A horizon is the layer of soil near the surface, and is roughly equivalent to topsoil. ... In ABC soil, the second or subsurface zone of soil made of clay and oxidized materials and organic matter obtained from the A horizon by leaching; subsoil. ... Sedimentary, volcanic, plutonic, metamorphic rock types of North America. ...

In Australia, most Entisols are known as Rudosols or Tenosols, whilst Arents are known as Anthroposols. In the FAO soil classification, because of the diversity of their properties, suborders of Entisols form individual soil orders (eg. Fluvisols, Lithosols). The FAO developed a supra-national classification, also called World Soil Classification, which offers useful generalizations about soils pedogenesis in relation to the interactions with the main soil-forming factors. ...

Causes of delayed or absent development:

• Unweatherable parent materials - sand, iron oxide, aluminium oxide, kaolinite clay.
• Erosion - common on shoulder slopes; other kinds also important.
• Deposition - continuous, repeated deposition of new parent materials by water, wind, colluvium, mudflows, other means.
• Flooding or saturation.
• Cold climate - must not be suffiently cold in winter for permafrost.
• Dry climate.
• Shallow to bedrock - may be "unweatherable" rock such as quartzite or ironstone.
• Toxic parent materials - serpentinite, mine spoils, sulfidic clays.

Patterns in the sand Sand is an example of a class of materials called granular matter. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metal Group, Period, Block 8 (VIIIB), 4, d Density, Hardness 7874 kg/m3, 4. ... An oxide is a chemical compound of oxygen with other chemical elements, e. ... General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13 (IIIA), 3, p Density, Hardness 2700 kg/m3, 2. ... Clay is a generic term for an aggregate of hydrous silicate particles less than 4 μm (micrometres) in diameter. ... In mathematics, the slope (or gradient, especially where three or more dimensions are discussed) of a straight line (within a Cartesian coordinate system) is a measure for the steepness of said line. ... Water (from the Anglo-Saxon and Low German wæter) is a colourless, tasteless, and odourless substance that is essential to all known forms of life and is the most universal solvent. ... Wind is the quasi-horizontal movement of air (as opposed to an air current) caused by a horizontal pressure gradient force. ... In many parts of the world, winter is associated with snow. ... This article is about frozen ground. ... Quartzite Quartzite is a hard, metamorphic rock which was originally sandstone. ... Ironstone is a fine-grained sedimentary rock, important as a source of iron. ... Serpentine Serpentine is a group of common rock-forming hydrous magnesium iron phyllosilicate ((Mg,Fe)3Si2O5(OH)4) minerals. ...

Suborders:

• Aquents - permentantly or usually wet soils formed on river banks, tidal mudflats etc. Here, general wetness limits development.

• Arents - anthropogenic soils: diagnostic horizons cannot develop because of deep mixing through plowing, spading, or other methods of moving by humans.

• Fluvents - alluvial soils where development is prevented by repeated deposition of sediment in periodic floods. Found in valleys and deltas of rivers, especially those with high sediment load.

• Orthents - shallow or "skeletal soils". Found on recent erosional surfaces or very old landforms completely devoid of weatherable minerals.

• Psamments - Entisols that are sandy in all layers where development is precluded by the impossibility of weathering the sand. Formed from shifting or glacial sand dunes.

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 water or other liquid. ... A flood (in Old English flod, a word common to Teutonic languages; compare German Flut, Dutch vloed from the same root as is seen in flow, float) is an overflow of water, an expanse of water submerging land, a deluge. ... This article is about the physical-geographic term. ... ---- <nowiki><nowiki>--~~~~ ---- --~~~~<nowiki>[[[[ == == == [[Image:NileDelta-EO.JPG|thumb|right|250px|Nile River delta, as seen from Earth orbit. ... Minerals are natural compounds formed through geological processes. ... Austrias longest glacier, the Pasterze, winds its 8 km (5 mile) route at the foot of Austrias highest mountain, the Grossglockner A glacier is a large, long-lasting river of ice that is formed on land and moves in response to gravity. ... This article is about the sand formations, for other meanings see Dune (disambiguation) Mesquite Flat Dunes in Death Valley National Park In physical geography, a dune is a hill of sand built by eolian (wind-related) processes. ...

Paleopedology

Most fossil soils before the development of terrestrial vegetation in the Silurian are Entisols, showing no distinct soil horizons. Entisols have been abundant in the paleopedological record ever since then, though, unlike other soil orders (Oxisols, Ultisols, Gelisols for instance) they do not have value as indicators of climate - though Orthents might in some cases be indicated of an extremely old landscape with very little soil formation (as in Australia today). FOSSIL is a standard for allowing serial communication for telecommunications programs under DOS. FOSSIL stands for Fido Opus Seadog Standard Interface Layer and was made by a group of Fidonet sysops to make their software work on different machines. ... Alternate use: The Silurians, a reptilian race from the science fiction series Doctor Who. The Silurian is a major division of the geologic timescale that extends from the end of the Ordovician period, about 439 million years before the present (BP), to the beginning of the Devonian period, about 408. ... The paleopedological record is, essentially, the fossil record of soils. ... Gelisols are an order in USA soil taxonomy. ...

See also

Pedogenesis
Pedology (soil study)
Soil classification

Pedogenesis or soil evolution (formation) is the process by which soil is created. ... Pedology, (from the Greek pedon = soil), is the study of soils and soil formation. ... Soil classification is the branch of soil science which deals with the systematic categorization of soils based on distinguishing characteristics developed during soil formation as well as criteria that dictate choices in land use and soil management. ...