The R layer is phyllite, calcareous metasiltstone and metasandstone, or metalimestone. The Bangor, Becket, Berkshire, Chatham, Chesuncook, Dixfield, Groveton, Houghtonville, Howland, Marlow, Plaisted, and Potsdam soils are more than 40 inches deep to bedrock. Battydoe soils have free carbonates. Dekapen, Revel and Welcome soils have a xeric moisture regime. In addition, Dekapen soils are moderately deep over basal till, Revel soils are moderately deep to a paralithic contact and Welcome soils are deep to a paralithic contact.
Elliottsville soils have less crushable rock fragments throughout.
Lombard soils have saprolite within 40 inches. Michigamme soils have less silt in the substratum. Tunbridge soils have less silt and less crushable rock fragments throughout. Onota soils have redder hues in the lower B horizons. Rawsonville soils have a spodic horizon 16 inches or more thick, or a Bh horizon 4 inches or more thick.