Spodic Materials

Publisher Summary This chapter discusses spodic materials. Spodic materials are generally associated with vertical and/or lateral translocation of organically complexed (cheluviated) forms of iron and aluminium. Fine organic and inorganic constituents composing spodic materials accumulate as a result of eluviation/illuviation processes and in situ transformations. Translocation of constituents is generally regarded to occur by organo-complexation of metals, but translocation of inorganic compounds is known to occur as well. These processes, in part governed by the properties of the soil in which they form, result in a variety of materials and distribution patterns in thin sections. One of the earliest applications of microscopic examination of undisturbed soil materials was for elucidation of the nature of spodic processes. This technique is important to determine the relative development of spodic horizons, especially the type, amount, and distribution of amorphous fine organic materials, the degree of cementation, and the sequence of the soil-forming processes.