Podsolization
Podsolization, or podzolization, is a pedogenic process in which highly leached, acidic soils remove soluble bases and silicate minerals from the upper horizons and accumulate iron and aluminum oxides and humus in a lower horizon. This translocation creates a characteristic sequence of eluviated and illuviated horizons. The upper eluviated layer, an E horizon, is pale in color due to depletion of iron and organic matter, while the lower illuvial horizon, often called a spodic horizon, concentrates organic matter with iron and aluminum oxides, and is commonly labeled Bh, Bhs, or Bs depending on composition.
Chemical mechanism involves organic acids from litter and humification processes mobilizing aluminum and iron, as well
Podsolization occurs most readily in cool, humid climates with well-drained sandy or acidic parent materials, especially