LOCATION STARKS             IL+IN 
Established Series
Rev. KAG-JWS-AAC
05/2008

STARKS SERIES


The Starks series consists of very deep, somewhat poorly drained soils formed in loess or other silty material and in the underlying loamy stratified outwash. They are on outwash plains, stream terraces, and alluvial fans. Slope ranges from 0 to 5 percent. Mean annual air temperature is about 11 degrees C (52 degrees F), and mean annual precipitation is about 940 mm (37 inches).

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Aeric Endoaqualfs

TYPICAL PEDON: Starks silt loam - in a nearly level cultivated field at an elevation of about 186 meters (610 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 25 cm (0 to 10 inches); dark grayish brown (10YR 4/2) silt loam, light brownish gray (10YR 6/2) dry; moderate fine granular structure; friable; few very fine roots; neutral; abrupt smooth boundary. [13 to 25 cm (5 to 10 inches) thick

E--25 to 36 cm (10 to 14 inches); grayish brown (10YR 5/2) silt loam; moderate fine subangular blocky structure; friable; few very fine roots; many distinct white (10YR 8/1) (dry) silt coatings on faces of peds; common fine faint brown (10YR 5/3) iron-manganese accumulations in the matrix; neutral; abrupt smooth boundary. [0 to 25 cm (0 to 10 inches) thick]

BE--36 to 43 cm (14 to 17 inches); 80 percent brown (10YR 4/3) and 20 percent grayish brown (10YR 5/2) silty clay loam; moderate fine subangular blocky structure; friable; few very fine roots; many prominent white (10YR 8/1) (dry) silt coatings on faces of peds; common fine faint yellowish brown (10YR 5/4) masses of oxidized iron in the matrix; few fine faint grayish brown (10YR 5/2) iron depletions in the matrix; neutral; abrupt smooth boundary.

Bt--43 to 53 cm (17 to 21 inches); brown (10YR 4/3) silty clay loam; weak fine prismatic structure parting to moderate fine angular blocky; friable; few very fine roots; many faint dark grayish brown (10YR 4/2) clay films on faces of peds; few fine rounded black (7.5YR 2.5/1) weakly cemented iron-manganese concretions throughout; common fine distinct yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; common fine faint grayish brown (10YR 5/2) iron depletions in the matrix; slightly acid; clear smooth boundary.

Btg1--53 to 64 cm (21 to 25 inches); gray (10YR 5/1) silty clay loam; weak fine prismatic structure parting to moderate fine angular blocky; friable; few very fine roots; common faint dark grayish brown (10YR 4/2) clay films on faces of peds; few fine rounded black (7.5YR 2.5/1) weakly cemented iron-manganese concretions throughout; common fine prominent brown (7.5YR 4/4) iron-manganese accumulations in the matrix; slightly acid; clear smooth boundary.

Btg2--64 to 79 cm (25 to 31 inches); grayish brown (2.5Y 5/2) silty clay loam; weak medium prismatic structure parting to moderate fine angular blocky; friable; few distinct dark grayish brown (10YR 4/2) clay films on faces of peds; common fine rounded black (7.5YR 2.5/1) weakly cemented iron-manganese concretions throughout; many medium prominent yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; slightly acid; clear smooth boundary. [Combined thickness of the Bt horizon is 25 to 71 cm (10 to 28 inches).]

2Btg3--79 to 109 cm (31 to 43 inches); grayish brown (2.5Y 5/2) stratified silt loam and sandy loam; weak medium prismatic structure parting to weak fine angular blocky; friable; few distinct dark grayish brown (10YR 4/2) clay films on faces of peds; common fine rounded black (7.5YR 2.5/1) weakly cemented iron-manganese concretions throughout; many medium prominent yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; neutral; clear smooth boundary. [23 to 76 cm (9 to 30 inches) thick]

2Cg--109 to 152 cm (43 to 60 inches); grayish brown (2.5Y 5/2) sandy loam that has thin strata of loamy sand; massive; very friable; many coarse prominent yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; neutral.

TYPE LOCATION: Livingston County, Illinois; about 2.4 kilometers (1.5 miles) south and 0.8 kilometers (0.5 miles) west of Manville; 9 meters (30 feet) south and 183 meters (600 feet) east of the northwest corner of sec. 33, T. 30 N., R. 4 E.; USGS Streator South, Illinois topographic quadrangle; lat. 41 degrees 01 minute 58 seconds N. and long. 88 degrees 46 minutes 27 seconds W., NAD 27; UTM Zone 16, 0350840 easting and 4543911 northing, NAD 83.

RANGE IN CHARACTERISTICS: Depth to the base of the argillic horizon ranges from 89 cm (35 inches) to more than 152 cm (60 inches). Depth to carbonates ranges from 102 to 178 cm (40 to 70 inches). Depth to horizons with more than 15 percent fine sand ranges from 61 to 102 cm (24 to 40 inches). The particle-size control section averages between 27 and 35 percent clay.

The Ap or A horizon has hue of 10YR, value of 4 or 5 (6 or 7 dry), and chroma of 1 to 3. Some pedons have an A horizon less than 18 cm (7 inches) thick with color value of 2 or 3 (4 or 5 dry). Texture is silt loam. Reaction ranges from strongly acid to neutral.

The Eg or E horizon has hue of 10YR, value of 5 or 6, and chroma of 2 or 3. It commonly has redoximorphic features. It is silt loam. Reaction ranges from strongly acid to neutral.

Some pedons have a BE horizon. It is silt loam or silty clay loam.

The Bt has hue of 2.5Y or 10YR, value of 4 to 6, and chroma of 1 to 4. Redoximorphic features have hue of 2.5Y, 10YR, or 7.5YR; value of 4 to 6; and chroma of 1 to 8. Texture is silty clay loam or silt loam. Reaction ranges from very strongly acid to slightly acid.

The 2Btg or 2BCg has hue of 2.5Y, 10YR, or 7.5YR; value of 4 to 6; and chroma of 1 to 6. It is loam, clay loam, silty clay loam, silt loam, or sandy loam. Clay content ranges from 10 to 30 percent and sand content ranges from 15 to 55 percent. Individual subhorizons have as much as 75 percent sand. Rock fragment content is less than 5 percent gravel. Reaction ranges from strongly acid to slightly alkaline.

The 2C has hue of 2.5Y, 10YR, or 7.5YR; value of 4 to 6; and chroma of 1 to 6. It is stratified and textures commonly are sandy loam, loam, silt loam, sandy clay loam, or clay loam. Some pedons contain thin strata of loamy sand. Clay content ranges from 5 to 30 percent and sand content ranges from 15 to 85 percent. Rock fragment content is less than 15 percent gravel. Reaction ranges from strongly acid to moderately alkaline.

COMPETING SERIES: These are the Aptakisic, Caseyville, Creal, Fitchville, Iva, Kendall, Stronghurst, Waynetown, and Yeddo series. Aptakisic soils have carbonates at a depth of 51 to 102 cm (20 to 40 inches). Caseyville, Fitchville, Iva, Stronghurst, and Yeddo soils average less than 15 percent sand in the lower parts of the series control section. Creal soils have a depth to the top of the argillic horizon ranging from 61 to 91 cm (24 to 36 inches). Kendall soils do not have horizons with more than 15 percent sand within a depth of 102 cm (40 inches). Waynetown soils have more than 15 percent gravel in the lower part of the series control section.

GEOGRAPHIC SETTING: Starks soils are on outwash plains, stream terraces, and alluvial fans. Slope ranges from 0 to 5 percent. These soils formed in 61 to 102 cm (24 to 40 inches) of loess or other silty material and in the underlying loamy stratified outwash. Mean annual air temperature ranges from 8 to 12 degrees C (46 to 54 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 104 to 415 meters (340 to 1,360 feet) above sea level.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brooklyn, Camden, Millbrook, and Sexton soils. The poorly drained Brooklyn and Sexton soils are lower on the landscape. The well drained Camden soils are on slightly higher or more sloping parts of the landscape. Millbrook soils are on similar landscapes nearby and form a biosequence with Starks soils. Camden and Sexton soils form a hydrosequence with Starks soils.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained. An intermittent apparent seasonal high water table is present at a depth of 15 to 61 cm (0.5 to 2.0 feet) below the surface at some time between January and May in normal years. The potential for surface runoff is negligible to low. Saturated hydraulic conductivity is moderately high or high (4.23 to 14.11 micrometers per second). Permeability is moderate.

USE AND VEGETATION: Most areas are cultivated. Corn, soybeans, and small grain are the principal crops. Some areas are wooded. Native vegetation is deciduous hardwood forest.

DISTRIBUTION AND EXTENT: Illinois and Indiana. The extent is large in MLRAs 95B, 108A, 108B, 110, 111A, 111B, 111D, 113, 114B, 115A, and 115C.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana.

SERIES ESTABLISHED: Menard County, Illinois, 1949.

REMARKS: A till substratum phase and flooded phase are recognized. These phases will be evaluated during MLRA updating to determine if new series are needed.

Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the surface to a depth of 36 cm (0 to 14 inches) (Ap and E horizon); albic horizon - the zone from 25 to 36 cm (10 to 14 inches) (E horizon); argillic horizon - the zone from about 36 to 79 cm (14 to 31 inches) (Bt, Btg1, Btg2 horizons); aquic conditions - redoximorphic features in all horizons below the Ap horizon; aquic moisture regime; mesic temperature regime.


National Cooperative Soil Survey
U.S.A.