Placic Horizon

{
  "id": "MLC-T-ENV-021105",
  "term": "Placic Horizon",
  "field": "Environment",
  "definition": "The placic horizon (Gr. base of plax, flat stone; meaning athin cemented pan) is a thin, black to dark reddish pan that is cemented by iron (or iron and manganese) and organic matter.It is generally between 2 and 10 mm thick but may be as thin as 1 mm. The placic horizon has a maximum thickness of 25mm where it is associated with spodic materials. Where not associated with spodic materials, it has no maximum thickness. It is often associated with stratification in parent materials, such as an abrupt discontinuity of hydraulic conductivity associated with different particle sizes in ash layers.",
  "references": [
    "USDA Natural Resources Conservation Service Soil Taxonomy: A Basic System of Soil Classification for Making and Interpreting Soil Surveys (1999)"
  ],
  "url": "https://mlchart.com/terminology/environment/placic-horizon/"
}