spodosol

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(Image source: USDA NRCS. Used with permission)

Heavily leached E horizon 
is common to spodosol soil

Spodosol soil is commonly found in cool, moist environments under coniferous forest vegetation. Surface litter composed of pine needles breaks down in the presence of water to form a weak organic acid. Acidic soil water removes base ions in solution to create an acidic soil. Easily dissolved materials are leached from surface layers leaving behind the most resistant material like quartz creating an ashy-grey, near-surface layer. Layers at depth are stained with iron and aluminum oxides.