LOCATION ARGYLE ILEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Mollic Hapludalfs
TYPICAL PEDON: Argyle silt loam on a northeast-facing, linear convex, 5 percent slope, moderately eroded, in a cultivated field at an elevation of 267 meters (878 feet) (Colors are for moist soil unless otherwise noted.)
Ap--0 to 18 cm (0 to 7 inches); black (10YR 2/1) silt loam; moderate fine and medium granular structure; friable; many fine and medium roots; moderately acid; clear smooth boundary. [15 to 25 cm (6 to 10 inches) thick]
BE--18 to 30 cm (7 to 12 inches); yellowish brown (10YR 5/4) silty clay loam; moderate fine and medium subangular blocky structure; firm; common fine and medium roots; very dark gray (10YR 3/1) worm channels; light gray (10YR 7/1) silt coatings on faces of peds; moderately acid; clear smooth boundary. [0 to 18 cm (0 to 7 inches) thick]
Bt1--30 to 56 cm (12 to 22 inches); yellowish brown (10YR 5/4) silty clay loam; strong fine and medium subangular blocky structure; firm; common fine roots; common distinct dark yellowish brown (10YR 4/4) clay films on faces of peds; strongly acid; abrupt smooth boundary. [15 to 33 cm (6 to 13) inches thick]
2Bt2--56 to 97 cm (22 to 38 inches); red (2.5YR 4/6) gravelly clay loam; moderate medium and coarse angular blocky structure; firm; few fine roots; common faint yellowish red (5YR 4/6) clay films, especially on pebbles; common fine black (N 2.5/) masses of iron and manganese oxides or organic coats; stone line in upper part of horizon; 25 percent gravel; strongly acid; clear smooth boundary.
2Bt3--97 to 178 cm (38 to 70 inches); red (2.5YR 4/6); gravelly sandy clay loam; moderate coarse angular blocky structure; firm; few fine roots; common distinct dark reddish brown (2.5YR 3/4) clay films on faces of peds; 20 percent gravel; strongly acid; clear smooth boundary. [Combined thickness of the 2Bt horizon is 64 to 127 cm (25 to 50) inches thick]
2BC--178 to 213 cm (70 to 84 inches); dark red (2.5YR 3/6) sandy loam; weak coarse angular blocky structure; friable; 5 percent gravel; slightly acid.
TYPE LOCATION: Carroll County, Illinois; about 4 miles northeast of Shannon; 2,200 feet south and 1,300 feet east of the northwest corner of sec. 4, T. 25 N., R. 7 E.; USGS Shannon topographic quadrangle; lat. 42 degrees 11 minutes 34 seconds N. and long. 89 degrees 42 minutes 11 seconds W., NAD 27.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 122 to more than 244 cm (4 to 8 or more feet). Thickness depends upon the amount of truncation of the Paleosol, which is the 2B horizon, before the loess was deposited. Where the solum is more than 5 feet thick, chroma is either less than 5 and hue is 7.5YR or redder or clay content decreases more than 20 percent from the maximum within depths of 152 cm (60 inches). The particle-size control section averages 27 to 35 percent clay and 15 to 35 percent fine and coarser materials.
The Ap horizon has a hue of 10YR, value of 2 or 3, and chroma of 1 or 2 It is silt loam. It averages 20 to 27 percent clay and 0 to 15 percent sand. It has weak or moderate, fine or medium granular structure and is friable. It ranges from strongly acid to slightly acid.
The E horizon, where present, has a hue of 10YR, value of 4 to 6, and chroma of 2 or 3. It is silt loam. It averages 15 to 26 percent clay and 0 to 20 percent sand. It has weak or moderate, thin or medium platy structure and is friable. It ranges from strongly acid to slightly acid. (some eroded pedons do not have an E horizon or the E horizon is less than 10 cm (4 inches) thick.)
The BE or Bt horizon has a hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 4 to 6. It is silty clay loam. It averages 27 to 35 percent clay and 0 to 20 percent sand. It has weak or moderate, fine or medium subangular blocky structure and is firm or friable. It ranges from strongly acid to slightly acid.
The 2Bt horizon has a hue redder than of 7.5YR to 2.5YR, value of 3 to 5, and chroma of 4 to 6. At least one horizon has a hue of 5YR or redder. It is clay loam, loam, sandy clay loam, or sandy loam. It averages 5 to 30 percent clay, 35 to 85 percent sand, 0 to 35 percent gravel, and 0 to 5 percent cobbles. It has moderate or strong, fine or medium, subangular blocky or angular blocky structure in the upper part of the 2Bt horizon and weak or moderate, medium or coarse, subangular blocky, angular blocky, or prismatic structure in the lower part of the 2Bt horizon. It is firm or friable. It ranges from strongly acid to slightly acid. The clay fraction contains a moderate amount of illite. Many of the properties are inherited from the soil formed in till prior to the time that the loess mantle was deposited. Some pedons have gravelly light sandy loam, sandy loam, or loam glacial till in which illite is the dominant clay mineral.
The 2BC horizon has a hue of 7.5YR to 2.5YR, value of 3 to 5, and chroma of 4 to 6. It is clay loam, loam, sandy clay loam, or sandy loam. It averages 5 to 30 percent clay 35 to 85 percent sand, 0 to 35 percent gravel, and 0 to 5 percent cobbles. It is weak medium or coarse subangular blocky, angular blocky, or prismatic structure. It is friable. It ranges from strongly acid to slightly
acid.
COMPETING SERIES: These are the Angus, Bassett, Blooming, Caleb, Cortland, Gara, Koronis, Lester, Newcomer, Orwood, Racine, Sebbo, Taopi, Waucoma, and Winneshiek Series. Angus, Blooming, Gara, Orwood, and, Racine soils lack hues redder than 7.5YR in the lower solum. Bassett series have 20 to 28 percent clay in the particle-size control section and lack hues redder than 7.5YR in the lower solum. Caleb soils formed in alluvial sediments derived from glaciers and lack red hues redder than 7.5YR in the lower solum. Cortland soils have 18 to 35 percent clay in the particle-size control section. Koronis and Lester soils contain Bk horizons and lack hues redder than 7.5YR in the lower solum. Newcomer, Waucoma and Winneshiek soils have a lithic contact within depths of 152 cm (60 inches). Sebbo soils have 18 to 25 percent clay in the particle-size control section and lack hues redder than 7.5YR in the lower solum. Taopi soils have a thinner solum, soft limestone or siltstone within 102 cm (40 inches), and lack hues redder than 7.5YR in the lower solum.
GEOGRAPHIC SETTING: Argyle soils are on gently rolling to moderately steep till plains and moraines. Slopes range from 2 to 18 percent. The upper part of the solum formed in 38 to 64 cm (15 to 25 inches) of loess or silty material and the lower part in reddish paleosols formed in glacial drift. Mean annual temperature is 7 to 14 degrees C (45 to 57 degrees F), and mean annual precipitation is 710 to 1020 mm (28 to 40 inches).
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pecatonica and Durand soils. Argyle soils are intermediate in properties between Pecatonica soils and the Durand soils which are on the same landscape. The Pecatonica soils have thinner A horizons and thicker or lighter colored E horizons. Durand soils have a mollic epipedon.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. Runoff is low on gentle slopes and medium on the steeper slopes. Saturated hydraulic conductivity is 4.23 to 14.11 micrometers per second (moderate permeability).
USE AND VEGETATION: Much of the Argyle soil is under cultivation. Crops most commonly grown are corn, soybeans, small grain, and meadow. Some is in pasture. Native vegetation was probably widely spaced trees and grass.
DISTRIBUTION AND EXTENT: Northwestern Illinois; LRRs K and M, MLRAs 108B and 95B. The series is of small extent.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Boone County, Illinois, 1935.
REMARKS: Diagnostic horizons and features in this pedon include:
Ochric epipedon - from a depth of 0 to 30 cm (0 to 12 inches) (Ap and BE horizons).
Argillic horizon - from a depth of 30 to 178 cm (12 to 70 inches) (Bt and 2Bt horizons)
Udic moisture regime; Mesic temperature regime
Particle-size control section--from a depth of 30 to 80 cm (12 to 32 inches) (Bt1 and 2Bt2 horizons)
Series control section - from a depth of 0 to 178 cm (0 to 70 inches) (Ap, BE, Bt2, 2Bt2, and 2Bt3 horizons)