UNI101Y1 Chapter Notes - Chapter 4: Parent Material, Podzol, Temperate Climate
16 Feb 2013
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Document Summary
In the temperate zone (mild temps. , moderate precipitation), sand grains and clay particles resist weathering and form stable components of the soil. Ppooddssoolliizzaattiioonn occurs in acidic soils in cool, moist regions of the temperate zone when clay particles in the e horizon break down and their soluble ions are transported downward and deposit in the lower b horizon. Usually occurs in regions where rainfall exceeds evaporation. B/c water continuously moves downward, little clay-forming material is transported upward. Acidic soils occur in cool regions dominated by needle-leaved trees. Slow decomposition of the needles produce organic acids which promote high conc. of. E: light-coloured, leached of clay (region of eluviation), consists mainly of sandy material. B: dark band, fe2+ and al3+ oxides are redeposited here (region of illuviation) Soil in warm, humid climates weather (tropics, subtropics) to great depths. Llaatteerriizzaattiioonn is the breakdown of clay particles resulting in the leaching of si4+ from the soil, leaving oxides of fe2+ and al3+
