LOCATION CHAUNCEY IL+MOEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Typic Argialbolls
TYPICAL PEDON: Chauncey silt loam - on an east-facing slope of about 2 percent in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 10 inches; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak fine granular structure; friable; slightly acid; abrupt smooth boundary.
A--10 to 13 inches; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak fine granular structure; friable; slightly acid; gradual smooth boundary. (The combined thickness of the Ap and A horizons is 10 to 15 inches.)
E1--13 to 19 inches; dark grayish brown (10YR 4/2) silt loam; few fine distinct dark yellowish brown (10YR 4/6) mottles; weak coarse platy structure parting to weak fine granular; friable; moderately acid; gradual smooth boundary.
E2--19 to 28 inches; grayish brown (10YR 5/2) silt loam; common fine distinct dark yellowish brown (10YR 4/6) mottles; weak medium platy structure parting to weak fine granular; friable; few fine black (10YR 2/1) concretions (Iron and manganese oxides); strongly acid; abrupt smooth boundary. (The combine thickness of the E horizon is 11 to 25 inches.)
Btg1--28 to 34 inches; dark gray (10YR 4/1) silty clay; many coarse distinct dark yellowish brown (10YR 4/6) mottles; strong medium prismatic structure parting to strong medium angular blocky; very firm; continuous thick dark gray (10YR 4/1) clay films on faces of peds; strongly acid; gradual smooth boundary.
Btg2--34 to 50 inches; gray (10YR 5/1) silty clay loam; many fine and coarse prominent strong brown (7.5YR 5/6) mottles; moderate coarse prismatic structure parting to weak medium and coarse angular blocky; firm; few fine distinct stains (Iron and manganese oxides); continuous thick dark gray (10YR 4/1) clay films of faces of peds; strongly acid; gradual smooth boundary.
Btg3--50 to 60 inches; gray (10YR 6/1) silty clay loam; common fine and medium prominent strong brown (7.5YR 5/6) mottles; weak coarse prismatic structure; firm; many thin dark gray (10YR 4/1) clay films on faces of peds; slightly acid; clear smooth boundary. (The combined thickness of the Bt horizon is 15 to 35 inches.)
TYPE LOCATION: Bond County, Illinois; about 4 miles south and 4 miles east of Pocahontas; 50 feet north and 115 feet east of the SW corner of sec 20, T. 4 N., R. 3 W.
RANGE IN CHARACTERISTICS: The thickness of the mollic epipedon ranges from 10 to 15 inches. The depth to the top of the argillic horizon ranges from 24 to 36 inches. The depth to the base of the argillic horizon ranges from 40 to 70 inches. The particle size control section averages between 35 and 42 percent clay and less than 10 percent sand.
The upper part of the control section (Ap or A horizon) has value of 2 or 3 moist (4 or 5 dry), and chroma of 1 or 2. Reaction ranges from slightly acid to very strongly acid.
The next part of the control section (E, Eg, or EBg horizon to a depth of at least 24 inches) has value of 4 to 7 moist (6 to 8 dry), and chroma of 1 or 2. Mottles have value of 3 to 5, and chroma of 2 to 8. Reaction ranges from moderately acid to very strongly acid.
Some pedons have a BE horizon which is less than 3 inches in thickness.
The next part of the control section (Btg horizon) has hue of 10YR, 2.5Y, or 5Y, value of 4 to 6, and chroma of 1 or 2. Mottles have hue of 10YR or 7.5YR, value of 3 to 6, and chroma of 2 to 6. It is silty clay loam or silty clay. Reaction ranges from very strongly acid to moderately acid.
The lower part of the control section (BCg, Cg, or 2Cg horizon) has hue of 10YR, 7.5YR, 2.5Y, or 5Y, value of 4 to 6, and chroma of 1 or 2. Mottles have hue of 10YR, 7.5YR, or 2.5Y, value of 4 or 5, and chroma of 1 to 8. It is silt loam, loam, clay loam, or silty clay loam. Reaction ranges from moderately acid to neutral.
COMPETING SERIES: These are the Barbert, Edina, Fillmore, Massie, Plankinton, Rolfe, Scott, and Sperry soils. Barbert soils average more than 45 percent clay in the particle size control section. Edina, Fillmore, Massie, Plankinton, Rolfe, Scott, and Sperry soils have the top of the argillic horizon within a depth of 24 inches.
GEOGRAPHIC SETTING: Chauncey soils are on nearly level plane interfluves or slightly concave foot slopes on till plains. They formed in more than 50 inches of loess. Slopes range from 0 to 3 percent. Mean annual air temperature ranges from 52 to 57 degrees F.; mean annual precipitation ranges from 35 to 45 inches; frost free days range from 170 to 200 days; and elevation ranges from 400 feet to 1,020 feet above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cisne, Cowden, Oconee, Richview, and Newberry soils. All the associated soils have dark colored surface layers less than 10 inches thick. The poorly drained Cowden, Cisne and Newberry soils are on broad, nearly level plains and interstream divides near Chauncey soils. The Oconee and Richview soils are better drained and are on convex ridges up slope from Chauncey soils.
DRAINAGE AND PERMEABILITY: Poorly drained. Surface runoff is slow. Permeability is slow.
USE AND VEGETATION: Most areas are used to grow corn, soybeans, and small grain. Native vegetation is wet-prairie grasses.
DISTRIBUTION AND EXTENT: Southern Illinois and Missouri. Chauncey soils are moderately extensive (about 19,000 acres correlated).
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Lawrence County, Illinois, 1952.
REMARKS: In some areas the lower part of the profile formed in Roxana silt and/or in pedisediment at the surface of the buried Sangamon soil.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon -- the zone form the surface to a depth of 13 inches (Ap and A horizon); albic horizon -- the zone from 13 to 28 inches (E horizon); argillic horizon -- the zone from 28 to 63 inches (Btg horizons); abrupt textural change between the E and Btg horizons.