A subsurface soil horizon, at least one-tenth the thickness of the overlying horizon, that is identified by the illuvial (see illuviation) accumulation of silicate clays. The amount of clay necessary is defined in comparison with the quantity in the overlying eluvial (see eluviation) horizon, but it is at least 20% more. Cutans may be used to identify an argic horizon. The name is from the Latin argilla meaning ‘white clay’.
Subjects: Science and technology — Life Sciences