LOCATION BROWNTON MN+IAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, calcareous, mesic Vertic Endoaquolls
TYPICAL PEDON: Brownton silty clay loam with slightly convex slope of less than 1/2 percent on a glacial lake plain in a cultivated field. (Colors for moist conditions unless otherwise stated.)
Ap--0 to 7 inches; black (10YR 2/1) silty clay loam; weak fine subangular blocky structure; friable; slightly alkaline; slight effervescence; abrupt smooth boundary.
A--7 to 15 inches; black (10YR 2/1) silty clay loam; moderate very fine and fine subangular blocky structure; friable; slightly alkaline, slight effervescence; clear wavy boundary. (Combined thickness of A horizon is 12 to 20 inches.)
AB--15 to 22 inches; very dark gray (10YR 3/1) silty clay; moderate fine subangular blocky structure; friable; common worm casts; few thin tongues of olive gray (5Y 5/2); strongly effervescent; slightly alkaline; gradual smooth boundary. (0 to 10 inches thick)
Bg--22 to 38 inches; dark gray (5Y 4/1) silty clay; moderate fine and very fine subangular blocky structure; firm; few channel fillings of very dark gray (10YR 3/1); many fine faint olive gray (5Y 5/2) Fe depletions and few fine distinct olive (5Y 5/4) Fe concentrations; strongly effervescent; slightly alkaline; clear wavy boundary. (6 to 20 inches thick)
2Cg1--38 to 44 inches; olive gray (5Y 5/2) clay loam; moderate fine and very fine subangular blocky structure; firm; about 5 percent gravel; few fine distinct olive (5Y 5/4) Fe concentrations; strongly effervescent; slightly alkaline; clear wavy boundary.
2Cg2--44 to 60 inches; olive gray (5Y 5/2) clay loam; massive; friable; common soft lime masses; about 5 percent gravel; common medium prominent light olive brown (2.5Y 5/6) Fe concentrations; strongly effervescent; slightly alkaline; clear wavy boundary.
TYPE LOCATION: Blue Earth County, Minnesota; about 6 miles east of Amboy; 1,980 feet north and 925 feet east of the southwest corner of sec. 23, T. 105 N., R. 29 W.
RANGE IN CHARACTERISTICS: The thickness of solum ranges from 24 to 44 inches. These soils have free carbonates in all parts, and the content of free carbonates ranges from 5 to 20 percent. The thickness of the lacustrine sediments and the depth to glacial till range from 30 to 60 inches or more. The lacustrine sediments contain less than 2 percent rock fragments by volume and the till contains 2 to 8 percent rock fragments. The 10 to 40 inch section averages between 35 and 55 percent clay (excluding clay-size carbonates) and from 2 to 25 percent sand. The solum is slightly alkaline or moderately alkaline. The mollic epipedon ranges from 12 to 24 inches in thickness.
The A horizon has hue of 10YR or 5Y, value of 2 or 3, and chroma of 1, or it is neutral with value of 2 or 3. It is silty clay loam, silty clay, or clay.
The B horizon has hue of 2.5Y or 5Y, value of 4 or 5, and chroma of 1 or 2. It is silty clay, clay, or silty clay loam.
The Cg horizon has hue of 2.5Y or 5Y, value of 4 to 6, and chroma of 2. It is silty clay loam, silty clay, or clay, but in some pedons it is silt loam. The reaction is slightly alkaline or moderately alkaline.
The 2Cg horizon has hue of 2.5Y or 5Y, value of 4 to 6, and chroma of 1 or 2. It is loam or clay loam. The reaction is slightly alkaline or moderately alkaline.
COMPETING SERIES: Egas and Kolda (T) series are in this family. Other similar soils are Marna, Silver Creek, and Spicer. The Egas soils have Cz horizons in the control section. The Kolda soils are drier in the soil moisture control section during the 120 days following the summer solstice. The Marna soils do not have free carbonates in the solum. The Silver Creek soils have formed in alluvium and are drier in the soil moisture control section. The Spicer soils are fine-silty.
GEOGRAPHIC SETTING: These soils have slightly concave to slightly convex slopes with gradients of less than 2 percent on glacial lake plains or lacustrine-mantled glacial moraines. They formed in 30 to 60 or more inches of clayey lacustrine sediments and loamy glacial till. These sediments are from the Des Moines lobe and are Late Wisconsinan in age. Mean annual temperature is 45 to 49 degrees F, and mean annual precipitation is 26 to 30 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the well drained Kamrar soils, the moderately well and somewhat poorly drained Guckeen and Collinwood soils, the poorly drained Barbert, Marna, and Waldorf soils, and the very poorly drained Lura soils. All of these soils formed at least in part from clayey lacustrine sediments. All of these soils do not have carbonates in all parts of their solums.
DRAINAGE AND PERMEABILITY: Poorly drained. Surface runoff is slow. Permeability is slow.
USE AND VEGETATION: Most of these soils are cropped to corn and soybeans. Native vegetation was a wet-site community of the tall grass prairie.
DISTRIBUTION AND EXTENT: South-central Minnesota and possibly north- central Iowa. Moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Blue Earth County, Minnesota, 1975.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface to 22 inches (Ap, A, and AB horizons); cambic horizon - the zone from 22 to 38 inches (Bg horizon); aquic moisture regime - low chroma immediately below mollic epipedon; calcareous family - effervescence in all parts between 10 and 20 inches (A, AB, and Bg horizons).
Classification only was changed 5/94. Competing series and other updates will be made later.
ADDITIONAL DATA: Refer to MAES Central File Code No. 966 for results of some laboratory analysis of a representative pedon of this series.