Parasmectic - Biasiallitic soil material in which smectite is identified, but is not the dominant mineral, smectite content ranges from 10 to 50 percent of the clay fraction. Quartz is not the dominant mineral in the clay fraction.

Biorthic - Typical bisiallitic soil material that consists of clay fractions containing appreciable amounts of vermiculite, mica and/or chlorite or identifiable amounts of smectite (usually > 10%). Various amounts of interstratified mica-vermiculite-chlorite, partially hydroxyinterlayered vermiculite or smectite, and interstratified mica-smectite have been identified in the Southern Region. Cation exchange capacities are generally greater than 30 meq/100g of clay. Typically, coarse fractions contain greater than 10% weatherable minerals.