1626. B horizon : Is a mineral horizon in which rock structure is obliterated or is but faintly evident, characterized by one or more of the following features: a) an illuvial cementation of silicate clay, iron, alumininum, or organic matter, above or in combination; b) a residual concentration of sesquioxides relative to source materials; c) an alteration of material from its original condition to the extent that silicate clays are formed, oxides are liberated, or both, or granular, blocky, or prismatic structure is formed. |