LOCATION VANPETTEN ILEstablished Series
TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Typic Hapludolls
TYPICAL PEDON: Vanpetten loam - on a 4 percent northeast facing slope in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; very dark gray (10YR 3/1) loam, dark grayish brown (10YR 4/2) dry;moderate very fine granular structure; friable; many fine roots; neutral; abrupt smooth boundary.
A--6 to 12 inches; very dark grayish brown (10YR 3/2) loam, grayish brown (10YR 5/2) dry; moderate fine granular structure; friable; many fine roots; slightly acid; clear smooth boundary. (Combined thickness of the A horizon is 10 to 15 inches.)
Bw1--12 to 16 inches; brown (10YR 4/3) silt loam; moderate fine subangular blocky structure; friable; many fine roots; many thin dark brown (10YR 3/3) organic coats on faces of peds; moderately acid; clear smooth boundary.
Bw2--16 to 24 inches; brown (10YR 4/3) silt loam; moderate medium subangular blocky structure; friable; common fine roots; few thin dark brown (10YR 3/3) organic coats on faces of peds; very strongly acid; clear smooth boundary.
Bw3--24 to 28 inches; brown (10YR 4/3) sandy loam; moderate medium subangular blocky structure; friable; common fine roots; few thin dark brown (10YR 3/3) organic coats on faces of peds; moderately acid; clear smooth boundary. (Combined thickness of the Bw horizon is 5 to 25 inches.)
2Bw4--28 to 37 inches; yellowish brown (10YR 5/4) coarse sand; weak medium subangular blocky structure; very friable; few fine roots; moderately acid; clear smooth boundary.
2Bt--37 to 50 inches; dark yellowish brown (10YR 4/6) loamy coarse sand; common fine distinct strong brown (7.5YR 5/6) mottles; weak coarse subangular blocky structure; very friable; few fine roots; common thin dark yellowish brown (10YR 4/4) clay films on faces of peds; slightly acid; abrupt smooth boundary. (Combined thickness of the 2Bw or 2Bt horizon is 12 to 36 inches.)
3Btg--50 to 66 inches; gray (5Y 5/1) clay loam; common fine prominent strong brown (7.5YR 5/6) mottles; moderate coarse prismatic structure; friable; few fine roots; few thin dark grayish brown (10YR 4/2) clay films on vertical faces of peds; moderately acid.
TYPE LOCATION: Lee County, Illinois; 4 1/2 miles northeast of Harmon; 287 feet north and 2,538 feet west of the southeast corner of sec. 19, T. 21 N., R. 9 E.
RANGE IN CHARACTERISTICS: The solum is 55 to 70 inches in thickness. The mollic epipedon is 10 to 15 inches in thickness. The 3Bt horizon is at depths less than 60 inches.
The A horizon has hue of 10YR, value of 2 or 3 (4 or 5 dry), and chroma of 1 to 3. It is loam or silt loam. It ranges from neutral to moderately acid.
The Bw or Bt horizon in eolian sediments has hue of 10YR, value of 4 or 5, and chroma of 3 or 4. It has mottles in some pedons that have hue of 10YR, value of 5 or 6, and chroma of 2 through 6. Exteriors of peds have organic coatings or clay films that have value of 3 in the upper part and 3, 4, or 5 in the lower part, and chroma of 1 through 3. The Bw or Bt horizon is silt loam or loam in the upper part and sandy loam, loam, or silt
loam in the lower part. It has weak or moderate structure and is friable. It ranges from very strongly acid to moderately acid.
The 2Bw or 2Bt horizon in outwash sediments has hue of 10YR or 7.5YR, value of 4 to 6, and chroma of 2 through 6. Mottles have hue of 10YR, 7.5YR, or 5YR, value of 4 through 6, and chroma of 1 through 8. The 2Bw or 2Bt horizon averages between 3 and
12 percent clay and between 75 and 95 percent sand. Individual subhorizons range from loam to coarse sand. Loamy subhorizons are less than 5 inches in thickness. Commonly there is an increase in content of clay just above the paleosol. The 2Bw or 2Bt horizon has weak or moderate structure and is friable. It ranges from extremely acid to slightly acid and is moderately acid or more acid in at least one subhorizon.
The 3Btg or 3Bt horizon has hue of 5Y, 2.5Y, 10YR, or 7.5YR, value of 3 through 7, and chroma of 1 through 8, and is mottled. It commonly is clay loam but ranges to include silt loam, loam, or silty clay loam. It has weak or moderate subangular blocky or prismatic structure and is friable or firm. It ranges from very strongly acid to neutral.
COMPETING SERIES: These are the
Cott,
Fairhaven,
Kanaranzi,
Wadena, and
Waukee series in the same family and the
Dakota,
Pillot, and
Waukegan series. All of the series in the same family have thinner sola and lack loamy paleosolic horizons in the lower part of the solum. Dakota and Pillot soils have argillic horizons. In addition, Pillot soils and the Waukegan soils contain less than 15 percent fine sand and coarser sand in
the upper part of the B horizon.
GEOGRAPHIC SETTING: Vanpetten soils are on convex slopes of gently undulating till plains that have thin deposits of loamy and sandy sediments. Slope gradients range from 1 to 5 percent. These soils formed in 18 to 35 inches of loamy eolian sediments and 12 to 36 inches of watersorted sandy sediments and in the underlying till that contains a paleosol. The till is believed to be of Illinoian age with a late Sangamon paleosol formed
in it. In some places it was partially truncated or eroded prior to deposition of the sandy and loamy sediments. The truncation of the paleosol and the origin of the sandy sediments is believed to be the result of glacial meltwaters from the nearby Shelbyville morainic system or the Bloomington morainic system.
Mean annual precipitation varies from 32 to 36 inches, and mean annual temperature varies from 48 to 51 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Dakota soils and the
Binghampton,
Nachusa,
Prairieville, and
Sparta soils. The well drained Dakota soils are on similar nearby areas where the sandy sediments extend to depths of 60 inches
or more. The somewhat poorly drained Binghampton and Nachusa soils commonly are downslope from Vanpetten soils and contain mottles higher in the solum. In addition, Nachusa soils lack coarse textured horizons and Binghampton soils lack a mollic
epipedon. The moderately well drained Prairieville soils occupy positions similar to Vanpetten soils but have more clay in the B horizon and lack coarse textured horizons. The excessively drained Sparta soils are sandy throughout the solum and are on higher dune-shaped ridges.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is medium. Permeability is moderate in the loamy sediments, very rapid in the sandy sediments, and moderately slow in the paleosolic horizons. Water commonly is perched above the
paleosolic horizon during winter and spring months.
USE AND VEGETATION: Mainly cropped. Corn, soybeans, and small grain are the principal crops. Native vegetation is prairie grass.
DISTRIBUTION AND EXTENT: Northern Illinois. These soils have small extent.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Lee County, Illinois, 1981. The name is adapted from the former village of Van Petten in Lee County, Illinois.
REMARKS: These soils do not have an argillic horizon within a depth of 40 inches but commonly have an increase in clay in the subhorizon above the paleosolic horizon.
ADDITIONAL DATA: Mechanical analysis and engineering test data for the typical pedon are on file in the SCS Illinois state office. The engineering tests were performed by the Illinois Department of Transportation.