LOCATION BLOUNT OH+IL IN MI WIEstablished Series
TAXONOMIC CLASS: Fine, illitic, mesic Aeric Epiaqualfs
TYPICAL PEDON: Blount silt loam - on a northwest-facing, concave, 1 percent slope in a cultivated field at an elevation of 867 feet. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 7 inches; dark grayish brown (10YR 4/2) silt loam, light brownish gray (10YR 6/2) dry; moderate fine and medium granular structure; friable; common roots; 3 percent pebbles; slightly acid; abrupt smooth boundary. (5 to 10 inches thick)
Btg--7 to 12 inches; grayish brown (10YR 5/2) silty clay; moderate medium subangular blocky structure; firm; common roots; common distinct dark grayish brown (10YR 4/2) clay films on surfaces of peds; common distinct light gray (10YR 7/1) (dry) clay depletions on vertical surfaces of peds; many distinct yellowish brown (10YR 5/4) masses of iron accumulation with clear boundaries in the matrix; 3 percent pebbles; strongly acid; clear wavy boundary.
Bt--12 to 23 inches; dark yellowish brown (10YR 4/4) clay; weak fine and medium prismatic structure parting to moderate medium subangular blocky; firm; few roots; many distinct grayish brown (10YR 5/2) clay films on faces of peds; many distinct dark grayish brown (10YR 4/2) iron depletions with clear boundaries in the matrix; common prominent gray (10YR 5/1) iron depletions with clear boundaries and distinct yellowish brown (10YR 5/6) masses of iron accumulation with diffuse boundaries in the matrix; 4 percent pebbles; slightly acid; clear wavy boundary. (Combined thickness of the Btg and/or Bt horizons is 12 to 35 inches.)
BCtg--23 to 30 inches; grayish brown (10YR 5/2) silty clay loam; weak medium subangular blocky structure; firm; few faint dark grayish brown (10YR 4/2) clay films on vertical surfaces of peds; few distinct light gray (10YR 7/2) calcium carbonate coatings on vertical surfaces of peds; many distinct dark yellowish brown (10YR 4/4) and common prominent yellowish brown (10YR 5/6) masses of iron accumulation with clear boundaries in the matrix; 8 percent pebbles; slightly effervescent; slightly alkaline; clear wavy boundary. (0 to 18 inches thick)
CBd--30 to 42 inches; brown (10YR 4/3) clay loam; weak medium platy structure; very firm; common distinct white (10YR 8/1) calcium carbonate coatings on surfaces; common faint grayish brown (10YR 5/2) iron depletions with diffuse boundaries in the matrix; 10 percent pebbles; strongly effervescent; moderately alkaline; gradual wavy boundary. (0 to 16 inches thick)
Cd1--42 to 54 inches; brown (10YR 5/3) clay loam; massive; very firm; common distinct light gray (10YR 7/1) calcium carbonate coatings on surfaces; few distinct dark gray (10YR 4/1) iron depletions with diffuse boundaries in the matrix; 10 percent pebbles; strongly effervescent; moderately alkaline; gradual wavy boundary.
Cd2--54 to 80 inches; brown (10YR 4/3) clay loam; massive; very firm; 10 percent pebbles; strongly effervescent; moderately alkaline.
TYPE LOCATION: Mercer County, Ohio; approximately 1.25 miles east of Wabash; in Washington Township; 130 feet west and 1880 feet south of the northeast corner of sec. 3, T. 6 S., R. 1 E.; Erastus Quadrangle; lat. 84 degrees 46 minutes 45 seconds N. and long. 40 degrees 33 minutes 35 seconds W., NAD 1927.
RANGE IN CHARACTERISTICS: The depth to the base of the argillic horizon ranges from 20 to 45 inches. The depth to carbonates ranges from 19 to 40 inches. Depth to the densic horizon is greater than 30 inches. The particle-size control section averages between 35 and 45 percent clay. Rock fragments are predominantly igneous, limestone, and dolomite pebbles.
The Ap horizon has a hue of 10YR, value of 3 or 4 (6 or more dry), and chroma of 1 to 3. Some pedons have an A horizon less than 5 inches in thickness that has color value of 2 or 3 ( 4 or 5 dry), and chroma of 1 or 2. The Ap or A horizon typically is silt loam but includes loam texture in some pedons. Some eroded pedons are silty clay loam. Rock fragment content ranges from 0 to 5 percent. Reaction ranges from strongly acid to neutral.
Some pedons have an E, BE or an EB horizon 3 to 6 inches thick. The E horizon has a hue of 10YR or 2.5Y, value of 4 or 5, and chroma 1 to 3.
The BE or EB horizon has color in the same range as the Bt horizon. It typically is silty clay loam but includes silt loam. Rock fragment content ranges from 0 to 10 percent. It ranges from strongly acid to neutral.
The Bt and Btg horizons have hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 1 to 4. They are silty clay loam, clay loam, clay, or silty clay. The clay content ranges from 35 to 48 percent in individual subhorizons. The sand content averages 10 to 25 percent. Rock fragment content ranges from 3 to 10 percent. They range from slightly acid to very strongly acid in the upper part and from moderately acid to slightly alkaline in the lower part.
The BCtg horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 1 to 6. It is silty clay loam, clay loam, or silty clay. Rock fragment content ranges from 3 to 15 percent. Reaction ranges from slightly acid to slightly alkaline and contains carbonates in some pedons. Some pedons have secondary carbonates (Bk horizon) as masses or as coatings on the underside of rock fragments in the lower B horizons. Some pedons do not have a BCtg horizon
The CBd and Cd horizons have hue of 10YR or 2.5Y, value of 4 through 6, and chroma of 2 to 4. They are silty clay loam or clay loam. Clay content ranges from 27 to 40 percent. Rock fragment content ranges from 5 to 15 percent. They are slightly alkaline or moderately alkaline. They have 22 to 35 percent calcium carbonate equivalent. Some pedons do not have a CBd horizon.
COMPETING SERIES: These are the Bennington, Brockport, Caneadea, Churchville, Del Rey, Fulton, Lockport, Kimmell, Mahoning, Nappanee, Odessa, Remsen, and Rhinebeck soils. Bennington and Mahoning soils have a calcium carbonate equivalent less than 22 percent and rock fragments that are dominantly shale, siltstone, or sandstone. Brockport and Lockport soils have a lithic or paralithic contact within 40 inches. Caneadea, Del Rey, Fulton, Odessa, and Rhinebeck soils contain less than 10 percent sand and generally less than 5 percent rock fragments in the lower part of the series control section. Churchville soils are formed in lacustrine deposits in the upper part of the series control section and have more rock fragments in the lower part of the series control section than Blount soils. Kimmell soils contain less than 5 percent rock fragments in the lower part of the series control section. Nappanee soils average more than 45 percent clay in the particle-size control section. Remsen soils contain more than 40 percent clay in the lower part of the series control section.
GEOGRAPHIC SETTING: Blount soils are on till plains of Wisconsinan Age. Slopes commonly are 1 to 3 percent and range from 0 to 6 percent. The soils formed in silty clay loam or clay loam till. Some areas have a mantle of loess or other silty material as much as 18 inches thick. Elevation ranges from 600 to 1500 feet. Mean annual temperature ranges from 45 to 55 degrees F, and mean annual precipitation ranges from 29 to 42 inches. The frost-free period is 130 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ashkum, Beecher, Glynwood, Lybrand, Morley, and Pewamo soils. The poorly drained Ashkum and Pewamo soils are in depressions and drainageways. The Beecher soils have a darker colored surface layer and are on similar nearby landforms. The moderately well drained Glynwood soils and well drained Lybrand and Morley soils are nearby on slightly higher or more sloping parts of the landform.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. The potential for surface runoff is low to medium. Permeability is slow. An intermittent perched seasonal high water table is at a depth of 0.5 to 2.0 feet in most years.
USE AND VEGETATION: Almost all areas of Blount soils are cultivated. Corn, soybeans, small grain, and meadow are the principal crops. Native vegetation is hardwood forest.
DISTRIBUTION AND EXTENT: Blount soils are in northern Illinois, Indiana, Michigan, Ohio, and Wisconsin. Dominant acreage is in MLRA 111, with lesser acreages in MLRA's 95B, 97, 98, 108, and 110. The extent of Blount soils is large; the acreage more than 2,500,000.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana.
SERIES ESTABLISHED: Vermilion County, Illinois, 1931.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
ochric epipedon - the zone from the surface of the soil to a depth of 7 inches (Ap horizon);
argillic horizon - the zone from approximately 7 to 30 inches (Btg, Bt, and BCtg horizons);
aquic conditions - 7 to 54 inches (Btg, Bt, BCtg, CBd, Cd1 horizons);
densic contact - 30 inches.
Supporting laboratory data is needed to confirm the presence of densic materials in the CBd and Cd horizons. Densic horizon is defined with this revision as being at depths of greater than 30 inches. Blount series is in major land region M and Churchville series is entirely in major land region R. There is some overlap in rock fragments in the lower part of the series control section but Churchville series is usually greater 15 percent and Blount series is less than 10 percent in most cases.
ADDITIONAL DATA: Laboratory characterization data is available for MC-20, the typical pedon. Other data are given in SSSA proc. 28: 674-679, Morley and Blount soils: A Statistical Summary of Certain Physical and Chemical Properties of some Selected Profiles in Ohio.