Jackson-Sherman soil weathering stages


Jackson-Sherman soil weathering stages

Table
      Jackson-Sherman soil weathering stages

 
      characteristic minerals in soil clay fraction

      characteristic chemical and physical conditions of soil

      characteristic soil profile features

early stage
      gypsum, carbonates, olivine/pyroxene/ amphibole, Fe2+-bearing micas, and feldspars

      low water and humus content, limited leaching, reducing environments, and limited time for weathering

      minimally weathered soils all over the world, though mainly in arid regions, where low rainfall keeps weathering to a minimum

intermediate stage
      quartz, mica/illite, vermiculite/chlorite, and smectite

      retention of Na, K, Ca, Mg, Fe2+, and silica; alkalinity
and ineffective leaching; igneous rock rich in Ca, Mg, and Fe2+ but no Fe2+ oxides; easily hydrolyzed silicates; and transport of silica into 
the weathering zone

      soils of temperate regions developed under grass or
trees—i.e., the major agricultural soils of the 
world

advanced stage
      kaolin, aluminum and 
iron oxides, and titanium oxides

      removal of Na, K, Ca, Mg, Fe2+, and silica; effective leaching by fresh water; low pH; and dispersion of silica

      intensely weathered soils of the humid tropics, frequently characterized by acidity and low fertility

See as table:

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Universalium. 2010.

Look at other dictionaries:

  • soil — soil1 soilless, adj. /soyl/, n. 1. the portion of the earth s surface consisting of disintegrated rock and humus. 2. a particular kind of earth: sandy soil. 3. the ground as producing vegetation or as cultivated for its crops: fertile soil. 4. a… …   Universalium


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