Solid Surfaces in Natural Soils

The structural similarity in illitic mica, vermiculite, and smectite minerals was noted in Sec. 1.1 (Table 1.3). The basal planes of these minerals are 

The three examples of the effects of pedochemical weathering on the surface structures in soil clays just described illustrate the complexity of the reactive solid materials in natural soils. To these examples can be added many others, including the formation of iron oxyhydroxide or calcium carbonate coatings on the external surfaces (as opposed to interlayer surfaces) of phyllosilicates, the development of thick envelopes of colloidal organic matter on aggregates of metal oxides and aluminosilicates, and the 

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