Entisol

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 flood as diluvium, aeolian processes which means by wind, slope processes as colluvium, mudflows, other means.
• Flooding or saturation.
• Cold climate – must not be sufficiently cold in winter for permafrost.
• Dry climate.
• Shallow to bedrock – may be rock resistant to weathering, such as quartzite or ironstone.
• Toxic parent materials – serpentine soil, mine spoils, sulfidic clays.

  Suborders

• Aquents – permanently or usually wet soils formed on river banks, tidal mudflats etc. Here, general wetness limits development.
• 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.
• Wassents – Entisols that have a positive water potential at the soil surface for more than 21 hours of each day in all years.

  Paleopedology