The presence of an argillic horizon is a primary diagnostic criterion for several soil orders in the USDA Soil Taxonomy, most notably:

The altered layer must be at least 15 centimeters thick.

Cambic Horizon

The presence of an argillic horizon is a primary diagnostic criterion for several soil orders in the USDA Soil Taxonomy, most notably:

The altered layer must be at least 15 centimeters thick. cambic horizon