LOCATION CERLIN IAEstablished Series
TAXONOMIC CLASS: Fine-loamy over clayey, mixed, superactive, mesic Aquic Argiudolls
TYPICAL PEDON: Cerlin silt loam - on a 1 percent convex southeast-facing slope in a bluegrass pasture. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; black (10YR 2/1) coatings on faces of peds; moderate fine granular structure; friable; slightly acid; clear smooth boundary.
A--8 to 14 inches; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; black (10YR 2/1) coatings on faces of peds; weak fine granular structure; friable; slightly acid; gradual smooth boundary. (Combined thickness of the A horizons is 10 to 17 inches.)
BA--14 to 18 inches; mottled brown (10YR 4/3) and dark grayish brown (10YR 4/2) silty clay loam; very dark gray (10YR 3/1) and very dark grayish brown (10YR 3/2) coatings on faces of peds; weak fine subangular blocky structure; friable; slightly acid; clear wavy boundary. (0 to 5 inches thick)
Bw1--18 to 24 inches; olive brown (2.5Y 4/4) silty clay loam; brown (10YR 4/3) coatings on faces of peds; many fine distinct light olive brown (2.5Y 5/6) and common fine distinct dark grayish brown (10YR 4/2) mottles; weak medium subangular blocky structure; friable; slightly acid; gradual smooth boundary.
Bw2--24 to 31 inches; olive brown (2.5Y 4/4) clay loam; dark grayish brown (10YR 4/2) and grayish brown (10YR 5/2) coatings on faces of peds; few fine distinct brownish yellow (10YR 6/6) mottles; weak medium subangular blocky structure; firm; medium acid; abrupt smooth boundary. (Combined thickness of the Bw horizons is 11 to 18 inches.)
2Bt1--31 to 37 inches; olive brown (2.5Y 4/4) silty clay; continuous dark gray (10YR 4/1) clay films on faces of peds; weak medium prismatic structure parting to strong very fine subangular blocky; very firm; few white (10YR 8/1) dry silt coats on faces of peds; medium acid; gradual smooth boundary.
2Bt2--37 to 54 inches; gray (10YR 5/1) silty clay; dicontinuous gray (10YR 5/1) clay films on faces of peds; few fine distinct brown (10YR 4/3) mottles; weak medium prismatic structure parting to moderate fine and medium subangular blocky; very firm; slightly acid; gradual smooth boundary.
2Bt3--54 to 63 inches; gray (10YR 5/1) silty clay; discontinuous gray (10YR 5/1) clay films on faces of peds; common fine distinct dark yellowish brown (10YR 4/4) mottles; moderate medium subangular blocky structure; very firm; a few coarse sand grains; neutral; gradual smooth boundary. (Combined thickness of the 2Bt horizons is 20 to 36 inches.)
2C--63 to 90 inches; gray (5Y 5/1) silty clay; common medium distinct olive brown (2.5Y 4/4) mottles; few strong brown (7.5YR 5/8) concretions (iron oxides); massive; extremely firm; neutral.
TYPE LOCATION: Cerro Gordo County, Iowa; about 2 miles west of Mason City; 800 feet west and 300 feet north of the center, sec. 1, T. 96 N., R. 21 W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 45 to 76 inches. Carbonates are absent in the solum. Reaction is medium acid or strongly acid in the most acid part of the loamy sediments and ranges from medium acid to neutral in the clayey paleosol. The surficial loamy sediments typically are 24 to 36 inches thick but range from 20 inches to 40 inches. In some pedons, a sandy loam or loamy sand horizon less than 5 inches thick is between the surficial sediments and the clayey material.
The Ap or A horizon typically is very dark brown (10YR 2/2), but ranges from black (10YR 2/1) to very dark grayish brown (10YR 3/2) with very dark brown (10YR 2/2 or black 10YR 2/1) coatings on faces of peds. An AB horizon is in some pedons. The A horizon typically is silt loam or loam with about 20 to 40 percent sand.
The BA horizon and the Bw horizon are clay loam or silty clay loam with about 15 to 40 percent sand. The BA horizon has hue of 10YR, value of 4 or 5, and chroma of 2 or 3. The Bw horizon has hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 3 or 4 and have few to many mottles with chroma of 2 to 6.
The 2Bt horizon dominantly has hue of 10YR through 5Y, value of 4 to 6, and chroma of 1 or 2. The upper part typically has chroma ranging from 2 to 4. Mottles range from few to many and from red (2.5YR 4/8) to olive brown (2.5Y 4/4). A few pedons lack mottles. The 2Bt horizon typically is clay or silty clay with about 42 to 55 percent clay. White (10YR 8/1) dry, uncoated sand grains and silt coatings typically are on the faces of peds in the 2Bt1 horizon.
The 2C horizon has hue of 10YR to 5Y, value of 5 or 6, and chroma of 1 to 6. It is silty clay, clay, clay loam, or loam. Clay content ranges from 25 to 45 percent.
COMPETING SERIES: These are the Papineau series in the same family and the Donnan, Jacwin, and Kenyon series. Papineau soils are shallower to carbonates and have a higher content of sand in the surficial materials. Donnan soils lack mollic epipedons. Jacwin soils have shale substrata. Kenyon soils contain less clay in the 2B and 2C horizons.
GEOGRAPHIC SETTING: Cerlin soils are on long, smooth convex slopes in a landscape with a dendritic drainage system. They are generally on convex ridges, but are also on convex sideslopes and slightly concave headslopes. Slope gradients typically are 1 to 5 percent but range from 0 to 9 percent. They formed in about 20 to 40 inches of surficial loamy sediments and highly weathered glacial till (paleosol). Mean annual temperature ranges from 45 to 50 degrees F, and mean annual precipitation ranges from about 30 to 34 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Donnan and Kenyon soils and the Dinsdale, Floyd, Klinger, and Readlyn soils. Donnan soils are on similar landscape positions as Cerlin soils. Dinsdale, Kenyon, Klinger, and Readlyn soils developed in loamy or silty surficial sediments and loam or clay loam glacial till. They are on convex slopes above and below Cerlin soils. Floyd soils occupy lower concave slopes and developed in loamy surficial sediments and stratified glacial till.
DRAINAGE AND PERMEABILITY: Moderately well and somewhat poorly drained. Permeability is moderate in the surficial sediments and very slow in the clayey material (paleosol) in the lower part of the solum. Surface runoff is slow to medium.
USE AND VEGETATION: This soil is commonly cropped to corn and soybeans and occasionally to small grains and hay. Native vegetation was tall prairie grasses.
DISTRIBUTION AND EXTENT: Northeastern and north central Iowa. They are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Cerro Gordo County, Iowa, 1978.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon--the zone from the surface of the soil to a depth of 14 inches (Ap and A horizons); argillic horizon--the zone from a depth of 31 to 63 inches (2Bt1, 2Bt2, and 2Bt3 horizons).