Bt2--51 to 84 centimeters (20.1 to 33.1 inches); silty clay; 10 percent coarse prominent (10YR 4/8) and 10 percent medium faint (10YR 7/8) mottles; weak medium subangular blocky structure; firm, very sticky, very plastic; few very fine roots between peds and few medium roots between peds; 35 percent distinct clay films on surfaces along pores and 35 percent distinct clay films on top faces of peds; 5YR 2.5/1) manganese masses; 2 percent sandstone fragments; gradual wavy boundary. Lab sample # 13N01589