LOCATION DUNHAM IL+OHEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Endoaquolls
TYPICAL PEDON: Dunham silty clay loam - on a north-facing slope with less than 1 percent gradient in a cultivated field at an elevation of 267 meters (877 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 15 cm (0 to 6 inches); black (N 2.5/) silty clay loam, dark gray (10YR 4/1) dry; weak fine subangular blocky structure parting to moderate fine and medium granular; friable; common very fine roots; neutral; clear smooth boundary.
A--15 to 30 cm (6 to 12 inches); black (N 2.5/) silty clay loam, dark grayish brown (10YR 4/2) dry; weak medium subangular blocky structure parting to moderate fine and medium granular; friable; common very fine roots; moderately acid; abrupt smooth boundary. [Combined thickness of the A horizon is 25 to 51 cm (10 to 20 inches).]
BAg--30 to 38 cm (12 to 15 inches); dark grayish brown (2.5Y 4/2) silty clay loam; weak fine and medium subangular blocky structure; friable; common very fine roots; common distinct very dark gray (2.5Y 3/1) organic coatings on faces of peds and in pores; few fine strong brown (7.5YR 5/6) very weakly cemented iron oxide concretions throughout; common fine distinct olive brown (2.5Y 4/4) masses of iron accumulation in the matrix; moderately acid; clear smooth boundary. [0 to 15 cm (0 to 6 inches) thick]
Btg1--38 to 61 cm (15 to 24 inches); grayish brown (2.5Y 5/2) silty clay loam; weak medium prismatic structure parting to moderate fine and medium subangular blocky; firm; common very fine roots; common distinct dark grayish brown (2.5Y 4/2) clay films on faces of peds; very few distinct very dark gray (2.5Y 3/1) organic coatings in root channels and pores; common fine black (10YR 2/1) very weakly cemented iron-manganese oxide concretions throughout; few fine strong brown (7.5YR 5/6) very weakly cemented iron oxide concretions throughout; common medium prominent yellowish brown (10YR 5/6) and common fine and medium distinct light olive brown (2.5Y 5/4) masses of iron accumulation in the matrix; slightly acid; gradual smooth boundary.
Btg2--61 to 79 cm (24 to 31 inches); grayish brown (2.5Y 5/2) silty clay loam; moderate medium prismatic structure parting to moderate medium angular blocky; firm; few very fine roots; few distinct dark grayish brown (2.5Y 4/2) clay films on faces of peds; very few distinct very dark grayish brown (2.5Y 3/2) organic coatings in root channels and pores; few fine dark brown (7.5YR 3/4) very weakly cemented iron oxide concretions throughout; common medium prominent strong brown (7.5YR 5/6) masses of iron accumulation in the matrix; slightly acid; clear smooth boundary.
Btg3--79 to 89 cm (31 to 35 inches); grayish brown (2.5Y 5/2) silty clay loam; weak medium prismatic structure parting to moderate medium subangular blocky; firm; few very fine roots; few distinct dark grayish brown (2.5Y 4/2) clay films on faces of peds; very few distinct very dark grayish brown (2.5Y 3/2) organic coatings in root channels and pores; many medium and coarse prominent strong brown (7.5YR 5/6) masses of iron accumulation in the matrix; 1 percent gravel; neutral; clear smooth boundary. [Combined thickness of the Btg horizon is 30 to 89 cm (12 to 35 inches).]
2Btg4--89 to 99 cm (35 to 39 inches); olive gray (5Y 5/2) clay loam; weak medium subangular blocky structure; friable; few very fine roots; few distinct olive gray (5Y 4/2) clay films on faces of peds; very few distinct dark olive gray (5Y 3/2) organic coatings in root channels and pores; many medium and coarse prominent strong brown (7.5YR 5/6) masses of iron accumulation in the matrix; 3 percent gravel; neutral; abrupt smooth boundary. [8 to 30 cm (3 to 12 inches) thick]
3Cg--99 to 112 cm (39 to 44 inches); olive gray (5Y 5/2) gravelly sandy loam; massive; very friable; few very fine roots; common fine faint light olive gray (5Y 6/2) iron depletions in the matrix; common fine prominent strong brown (7.5YR 4/6) masses of iron accumulation in the matrix; 25 percent gravel; strongly effervescent; slightly alkaline; clear smooth boundary.
3C--112 to 152 cm (44 to 60 inches); brown (10YR 5/3) gravelly loamy sand and gravelly loamy fine sand; single grain; loose; few very fine roots; common fine and medium faint grayish brown (10YR 5/2) iron depletions in the matrix; common fine and medium distinct yellowish brown (10YR 5/6) masses of iron accumulation in the matrix; 25 percent gravel; strongly effervescent; slightly alkaline.
TYPE LOCATION: McHenry County, Illinois, about 4.8 kilometers (3 miles) southwest of Harvard; 286 meters (939 feet) south and 25 meters (81 feet) west of the center of sec. 15, T. 45 N., R. 5 E.; USGS Capron, Illinois, topographic quadrangle; lat. 42 degrees 22 minutes 33 seconds N. and long. 88 degrees 38 minutes 16 seconds W., NAD 27; UTM Zone 16, 365154 easting and 4692807 northing, NAD 83.
RANGE IN CHARACTERISTICS: The depth to the base of the cambic horizon ranges from 91 to 140 cm (36 to 55 inches). The depth to horizons with more than 15 percent sand ranges from 61 to 127 cm (24 to 50 inches). The depth to horizons with more than 75 percent sand and more than 15 percent rock fragments ranges from 81 to 140 cm (32 to 55 inches). The mollic epipedon ranges from 25 to 51 cm (10 to 20 inches) in thickness. The depth to carbonates ranges from 76 to 127 cm (30 to 50 inches). The series control section ranges from moderately acid to neutral in the upper part and from slightly acid to moderately alkaline in the lower part.
The Ap or A horizon has hue of 10YR, 2.5Y, or is neutral, value of 2 to 3, and chroma of 0 to 2. Texture is silty clay loam and less commonly silt loam. Some pedons have an AB horizon.
The BAg, Btg and/or Bg horizon has hue of 10YR, 2.5Y, 5Y, or is neutral, value of 4 to 6, and chroma of 0 to 2. Redoximorphic features have chroma of 0 to 8. Texture is silty clay loam in the upper part and silty clay loam or silt loam in the lower part.
The 2Btg or 2BCg horizon has hue of 10YR, 2.5Y, 5Y, or is neutral, value of 5 or 6, and chroma of 0 to 2. Redoximorphic features have chroma of 0 to 8. Texture is loam, clay loam, silt loam, sandy loam, or their gravelly analogs. Rock fragment content ranges from 0 to 20 percent.
The 3Cg or 3C horizon has hue of 7.5YR, 10YR, 2.5Y, 5Y, or is neutral, value of 4 to 7, and chroma of 0 to 8. It ranges from gravelly sandy loam to extremely gravelly coarse sand. Rock fragment content ranges from 15 and 70 percent. Sand content ranges from 75 to 98 percent.
COMPETING SERIES: These are the Chalmers, Chetomba, Dolbee, Drummer, Elpaso, Elvira, Garwin, Gillett Grove, Hartsburg, Madelia, Marcus, Mascoutah, Maxfield, Maxcreek, Maxmore, Ossian, Patton, Pella, Rushmore, Sable, and Wacousta series. All competing series except the Rushmore series contain less than 15 percent rock fragments in the lower part of the series control section. Rushmore soils average less than 75 percent sand in the lower part of the series control section.
GEOGRAPHIC SETTING: Dunham soils are in depressions or on nearly level parts of outwash plains and stream terraces. Slope gradients range from 0 to 2 percent. Dunham soils formed in 61 to 127 cm (24 to 50 inches) of loess or other silty material and in the underlying loamy outwash over sandy and gravelly deposits. Mean annual air temperature ranges from 7 to 12 degrees C (44 to 53 degrees F), mean annual precipitation ranges from 740 to 1020 mm (29 to 40 inches), frost-free period ranges from 140 to 180 days, and elevation ranges from 155 to 320 meters (510 to 1050 feet) above mean sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Bowes, Grundelein, Millstream, Rush, and Waupecan soils. The associated soils are on higher positions on the landform. The somewhat poorly drained Grundelein and well drained Waupecan soils form a drainage sequence with Dunham soils. The well drained Bowes and Rush soils and the somewhat poorly drained Millstream soils do not have mollic epipedons.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained. In drained conditions an apparent high water table is at 15 cm (0.5 foot) above the surface to 30 cm (1 foot) below the surface in most years and, in undrained conditions, it is 15 cm (0.5 foot) above the surface to 15 cm (0.5 foot) below the surface. The potential for surface runoff is negligible. Saturated hydraulic conductivity is moderately high or high (4.23 to 14.11 micrometers/s) in the solum and very high (> 141.11 micrometers/s) in the underlying material. Permeability is moderate in the solum and very rapid in the underlying material.
USE AND VEGETATION: Most areas are used to grow corn and soybeans. Some areas are used for growing small grain or meadow. Native vegetation is hydrophytic grasses, reeds, and sedges.
DISTRIBUTION AND EXTENT: MLRAs 95B, 110, and 111D in northern Illinois, southwest Ohio, and possibly southern Wisconsin. The extent is moderate.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana.
SERIES ESTABLISHED: McHenry County, Illinois, 1996.
REMARKS: This soil was formerly mapped Drummer in McHenry County. It is named for the McHenry County township in which the type location resides. It was determined that Dunham soils range from 15 to 70 percent gravel in the lower part of series control section. Drummer series will be restricted to 0 to 15 percent gravel in the lower part.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface to a depth of 30 cm (12 inches) (Ap and A horizons); cambic horizon - the zone from approximately 30 to 99 cm (12 to 39 inches) (BAg, Btg1, Btg2, Btg3, and 2Btg4 horizons); aquic conditions - redoximorphic features present in the zone from approximately 30 to 152 cm (12 to 60 inches) (BAg, Btg1, Btg2, 2Btg3, 2Btg4, 3Cg, and 3C horizons).