LOCATION BRYCE IL+INEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Vertic Endoaquolls
TYPICAL PEDON: Bryce silty clay - on a concave slope of less than 1 percent in a cropped field at an elevation of 206 meters (675 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap1--0 to 25 cm (0 to 10 inches); black (10YR 2/1) silty clay, dark gray (10YR 4/1) dry; weak very fine granular structure; friable; few fine black (7.5YR 2.5/1) weakly cemented iron-manganese nodules throughout; slightly acid; abrupt smooth boundary.
Ap2--25 to 33 cm (10 to 13 inches); black (10YR 2/1) silty clay, dark gray (10YR 4/1) dry; moderate medium angular blocky structure; friable; moderately acid; abrupt smooth boundary.[Combined thickness of the A horizon is 25 to 46 cm (10 to 18 inches).
Bg--33 to 48 cm (13 to 19 inches); black (10YR 2/1) silty clay, dark gray (10YR 4/1) dry; moderate fine and medium subangular blocky structure; friable; many distinct black (10YR 2/1) organic coatings on faces of peds; common fine distinct dark grayish brown (2.5Y 4/2) and few fine distinct grayish brown (10YR 5/2) iron depletions in the matrix; slightly acid; clear wavy boundary.
Btg1--48 to 61 cm (19 to 24 inches); dark grayish brown (2.5Y 4/2) silty clay; weak medium prismatic structure parting to moderate fine and medium subangular blocky; firm; many distinct dark gray (10YR 4/1) clay films on faces of peds; many distinct black (N 2.5/) organo-clay films on faces of peds; common fine prominent yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; neutral; clear wavy boundary.
Btg2--61 to 89 cm (24 to 35 inches); olive gray (5Y 5/2) silty clay; moderate medium prismatic structure parting to moderate medium subangular blocky; firm; common distinct olive gray (5Y 4/2) clay films on faces of peds; common distinct very dark gray (10YR 3/1) organo-clay films on faces of peds; few slickensides on faces of peds; common fine black (7.5YR 2.5/1) weakly cemented iron-manganese nodules throughout; common fine faint dark gray (2.5Y 4/1) iron depletions in the matrix; common fine prominent strong brown (7.5YR 5/6) masses of oxidized iron in the matrix; neutral; gradual smooth boundary.
Btg3--89 to 114 cm (35 to 45 inches); gray (5Y 5/1) silty clay; weak coarse prismatic structure parting to weak coarse subangular blocky; firm; few fine roots; few distinct dark gray (5Y 4/1) clay films on faces of peds; few slickensides and pressure faces on faces of peds; common medium prominent light olive brown (2.5Y 5/4) and few medium prominent dark yellowish brown (10YR 4/4) iron-manganese accumulations in the matrix; slightly alkaline; clear smooth boundary. [Combined thickness of the Bg and Btg horizons is 20 to 89 cm (8 to 35 inches).]
2BCg--114 to147 cm (45 to 58 inches); gray (5Y 5/1) silty clay; weak very coarse prismatic structure; very firm; few fine white (10YR 8/1) very weakly cemented nodules and concretions of calcium carbonate throughout; common coarse prominent brown (10YR 4/3) iron-manganese accumulations and common medium prominent yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; 1 percent gravel; slightly effervescent; moderately alkaline; clear smooth boundary. (5 to 15 inches or 13 to 38 cm thick)
2Cg--147 to 168 cm (58 to 66 inches); gray (5Y 5/1) silty clay; massive; very firm; many medium prominent olive brown (2.5Y 4/4) iron-manganese accumulations in the matrix; 3 percent gravel; slightly effervescent; slightly alkaline.
TYPE LOCATION: Iroquois County, Illinois; about 5 miles (8 kilometers) north of Cissna Park; 2,559 feet (780 meters) north and 45 feet (14 meters) west of the center of sec. 7, T. 25 N., R. 13 W.; USGS Woodworth topographic quadrangle; lat. 40 degrees 38 minutes 39 seconds N. and long. 87 degrees 52 minutes 23 seconds W., NAD 27; UTM Zone 16, 426178 easting and 4499628 northing, NAD 83.
RANGE IN CHARACTERISTICS: The depth to the base of soil development ranges from 76 cm (30 inches) to more than 152 cm (60 inches). Thickness of the water-sorted sediments typically is about 102 to 122 cm (40 to 48 inches) but ranges from 38 to 140 cm (15 to 55 inches). The mollic epipedon ranges from 25 to 61 cm (10 to 24 inches) in thickness. It includes the upper part of the B horizon in some pedons. Carbonates are in the lower part of the cambic horizon in some pedons. The Cg or 2Cg horizon is calcareous. The particle-size control section averages between 42 and 52 percent clay.
The Ap or A horizon has hue of 10YR or is neutral, value of 2 to 3 (3 to 5 dry), and chroma of 1 or 0. It is silty clay or silty clay loam. Reaction ranges from moderately acid to slightly alkaline.
Some pedons have an AB or BA horizon that is silty clay or silty clay loam.
The Bg, Btg, or BCg horizon has hue of 10YR, 2.5Y, 5Y, or is neutral, value of 2 to 6, and chroma of 0 to 3. Value of 2 or 3 is limited to the upper few inches of the horizon. Texture is silty clay or clay. Clay content ranges from 42 to 52 percent and sand content ranges from 5 to 20 percent. Gravel content is less than 5 percent. Reaction ranges from neutral to moderately alkaline.
The 2BCg or 2Cg horizon commonly has hue of 2.5Y or 5Y and value of 4 to 6. The 2BCg horizon has chroma of 1 or 2 and the 2Cg horizon has chroma of 1 to 8. Texture commonly is silty clay or clay, but some pedons are silty clay loam. Clay content ranges from 38 to 60 percent and sand content ranges from 5 to 20 percent. Gravel content is less than 10 percent. Reaction is slightly alkaline or moderately alkaline. Moist bulk density ranges from 1.60 to 1.75 g/cc.
COMPETING SERIES: This is the only series in this family.
GEOGRAPHIC SETTING: Bryce soils are on low-lying nearly level areas on till plains or glacial lake plains of Wisconsinan Age. They formed in clayey water-sorted sediments and in the underlying clayey calcareous till. The upper sediments are lacustrine or local colluvial sediments from surrounding slopes or a combination of both kinds of sediments and increment or admixed loess. The sediments have a broader spectrum of clay minerals, lower bulk density, and greater available water capacity than the underlying till. Slope gradients commonly are less than 1 percent and range from 0 to 2 percent. Mean annual temperature ranges from 9 to 11 degrees C (48 to 52 degrees F), mean annual precipitation ranges from 740 to 890 mm (29 to 35 inches), frost-free period ranges from 160 to 180 days, and elevation ranges from 183 to 305 meters (600 to 1,000 feet) above mean sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Mokena, Rantoul, Rutland, and Swygert soils. The somewhat poorly drained Mokena, Rutland, and Swygert soils are on nearby higher elevations or more sloping areas or both. Mokena soils are fine-loamy. Rutland soils contain 35 to 45 percent clay in the control section and have loess in the upper few feet of the solum. Swygert soils formed in similar materials and form a drainage sequence with Bryce soils. The very poorly drained, very slowly permeable Rantoul soils are in nearby lower-lying depressions and have higher COLE values.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained. Where drained, the depth to an apparent seasonal high water table is 15 cm (0.5 foot) above the surface to 30 cm (1.0 foot) below the surface at some time between January and May in most years. The potential for surface runoff is negligible. Saturated hydraulic conductivity is moderately low (less than 0.42 micrometers per second). Permeability is very slow.
USE AND VEGETATION: Most areas are used for cropland. Principal crops are corn and soybeans and other crops include small grain and meadow. Native vegetation is marsh grasses and sedges.
DISTRIBUTION AND EXTENT: Northeastern Illinois and northwestern Indiana. These soils are of large extent in MLRAs 110 and 108A
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana.
SERIES ESTABLISHED: Iroquois County, Illinois, 1940.
REMARKS: In soils such as this, with materials in the control section of mixed origin, clay mineralogy determinations are imprecise. Several indicators should be used. The X-ray diffraction patterns at NSSL indicate a montmorillonitic placement. However, that method should be compared to weighted CEC/clay and LE/clay ratios which are outside the limits commonly set for the smectitic mineralogy class. The relative proportions of clay minerals, is a function of the kind and amount of mixing of materials over the till. In all pedons the mineralogy of the till is illitic.
A bedrock substratum phase is recognized. These soils will be evaluated during MLRA updating to determine if new series needed.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon 0 to 48 cm (0 to 19 inches) (Ap1, Ap2, and Bg horizons); cambic horizon 33 to 152 cm (13 to 60 inches) (Bg, Btg1, Btg2, Btg3, and 2BCg horizons).
ADDITIONAL DATA: The typical pedon is S77IL-075-6 (NSSL Nos. 77P 1079 - 77P 1085) from a characterization study of soils formed in fine-textured materials in northeastern Illinois.