LOCATION LAKASKIA ILEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Vertic Argiaquolls
TYPICAL PEDON: Lakaskia silt loam - on a rarely flooded, nearly level lake plain in a cultivated field at an elevation of about 412 feet above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; very dark gray (10YR 3/1) silt loam, gray (10YR 5/1) dry; weak thin platy structure parting to weak fine granular; friable; common very fine roots; few fine continuous tubular pores; few fine rounded strong brown (7.5YR 4/6) and black (N 2.5/0) iron-manganese nodules with sharp boundaries; neutral; abrupt smooth boundary.
A--8 to 13 inches; very dark gray (10YR 3/1) silty clay loam, dark gray (10YR 4/1) dry; moderate fine angular blocky structure; friable; common very fine roots; few fine continuous tubular pores; few fine rounded strong brown (7.5YR 4/6) and black (N 2.5/0) iron-manganese nodules with sharp boundaries; neutral; abrupt smooth boundary. (Combined thickness of the A horizon is 10 to 18 inches.)
Btg1--13 to 17 inches; dark grayish brown (2.5Y 4/2) silty clay loam; moderate medium prismatic structure; firm; common very fine roots; few fine constricted tubular pores; few distinct very dark gray (10YR 3/1) organo-clay films on faces of peds; few fine prominent dark yellowish brown (10YR 4/4) masses of iron accumulation in the matrix; few fine irregular black (7.5YR 2.5/1) and strong brown (7.5YR 5/6) iron-manganese nodules with clear boundaries; neutral; clear smooth boundary.
Btg2--17 to 26 inches; grayish brown (2.5Y 5/2) silty clay loam; weak medium prismatic structure; firm; few very fine roots; many distinct dark grayish brown (2.5Y 4/2) clay films on faces of peds; few fine distinct light olive brown (2.5Y 5/4) masses of iron accumulation in the matrix; few fine and medium rounded black (7.5YR 2.5/1) and strong brown (7.5YR 4/6) iron-manganese nodules with clear boundaries; neutral; clear smooth boundary. (Combined thickness of the Btg horizon is 8 to 16 inches.)
2Btkg1--26 to 36 inches; grayish brown (2.5Y 5/2) silty clay; weak medium prismatic structure; firm; many distinct dark grayish brown (2.5Y 4/2) clay films on faces of peds; common fine distinct light olive brown (2.5Y 5/6) masses of iron accumulation in the matrix; few fine and medium irregular black (7.5YR 2.5/1) and strong brown (7.5YR 5/6) iron-manganese nodules with clear boundaries; few coarse irregular light gray (10YR 7/2) carbonate concretions; slightly effervescent; slightly alkaline; gradual smooth boundary.
2Btkg2--36 to 50 inches; grayish brown (2.5Y 5/2) silty clay loam; weak coarse prismatic structure; firm; many distinct dark grayish brown (2.5Y 4/2) clay films on faces of peds; common fine distinct light olive brown (2.5Y 5/6) masses of iron accumulation in the matrix; few coarse rounded black (10YR 2/1) iron-manganese concretions and few fine irregular strong brown (7.5YR 5/6) iron-manganese nodules with clear boundaries; few coarse irregular light gray (10YR 7/2) carbonate concretions; slightly effervescent; slightly alkaline; clear smooth boundary. (Combined thickness of the 2Btkg horizon is 18 to 28 inches.)
2BCtkg--50 to 60 inches; olive gray (5Y 5/2) silty clay loam; weak medium prismatic structure; firm; common distinct dark grayish brown (2.5Y 4/2) clay films on vertical faces of peds and lining root channels; few shiny nonintersecting slickensides; common medium prominent dark yellowish brown (10YR 4/6) masses of iron accumulation in the matrix; common fine and medium rounded black (10YR 2/1) iron-manganese concretions and common medium and coarse irregular strong brown (7.5YR 5/6) iron-manganese nodules with diffuse boundaries; common medium and coarse irregular light gray (10YR 7/2) carbonate concretions with white (10YR 8/1) coatings; slightly effervescent; slightly alkaline; clear smooth boundary. (0 to 12 inches thick)
2Cg--60 to 82 inches; light olive gray (5Y 6/2) clay loam; massive with horizontal planes of weakness; friable; few fine and medium vesicular pores; few distinct dark grayish brown (2.5Y 4/2) clay films lining root channels and filling pores; common medium prominent yellowish brown (10YR 5/6) masses of iron accumulation in the matrix; common medium and coarse black (10YR 2/1) masses of iron manganese accumulation with diffuse strong brown (7.5YR 5/6) boundaries; slightly effervescent; slightly alkaline.
TYPE LOCATION: Clinton County, Illinois; about 4 miles south of Germantown; approximately 2,297 feet west and 2,510 feet south of the northeast corner of sec. 27, T. 1 N., R. 4 W.; USGS Breese, IL. topographic quadrangle; lat. 38 degrees 30 minutes 3 seconds N. and long. 89 degrees 31 minutes 27 seconds W.
RANGE IN CHARACTERISTICS: Depth to the base of the argillic horizon is 40 to 74 inches. Loess thickness ranges from about 18 inches to 34 inches. Thickness of the mollic epipedon is 10 to 18 inches and it extends into the Btg horizon in some pedons. Rock fragment content is less than 1 percent by volume in the upper three-quarters of the series control section and less than 10 percent by volume in the lower one-quarter.
The upper part of the series control section (Ap and A) has value of 2 or 3 and chroma of 1 or 2. Texture is silt loam or silty clay loam. Clay content averages 20 to 30 percent and sand content is less than 10 percent. Reaction is moderately acid to neutral, depending on the liming history.
The second part of the series control section (Btg) has hue of 10YR, 2.5Y, or is neutral; value of 3 to 6; and chroma of 0 to 2. Texture is silty clay loam or silty clay. Clay content averages 30 to 42 percent and sand content is less than 10 percent. Individual subhorizons range from 28 to 48 percent clay and range to 15 percent sand. Reaction is moderately acid to slightly alkaline.
The third part of the series control section (2Btg or 2Btkg) has hue of 10YR, 2.5Y, 5Y, or is neutral; value of 4 to 6; and chroma of 0 to 2. Texture is silty clay loam or silty clay. Clay content averages 35 to 45 percent and sand content is less than 10 percent. Individual subhorizons range from 28 to 50 percent clay and range to 15 percent sand. Reaction is slightly acid to moderately alkaline. Carbonates are common, but are not everywhere present.
The fourth part of the control section (2BCtg,2BCg or 2BCtkg) has hue of 10YR, 2.5Y, 5Y, or is neutral; value of 4 to 6; and chroma of 0 to 2. Texture is silt loam, silty clay loam, or silty clay. Clay content averages 25 to 42 percent and sand content is less than 10 percent. Individual subhorizons range from 22 to 48 percent clay and range to 15 percent sand. Reaction is neutral to moderately alkaline. Carbonates are common, but are not everywhere present.
The lower part of the control section (2C or 2Cg) has hue of 10YR, 2.5Y, or 5Y; value of 4 to 6; chroma of 1 to 4. Clay content averages 22 to 35 percent and sand content averages 5 to 15 percent. Individual strata range from 18 to 50 percent clay and range to 35 percent sand. Reaction is neutral to moderately alkaline. Some pedons contain carbonates.
COMPETING SERIES: These are the Conser, Konert, Reed and Rowe series.
The Conser, Konert and Reed soils have a mean annual soil temperature less than 56 degrees F. The Rowe soils average more than 48 percent clay in the middle parts of the series control section.
GEOGRAPHIC SETTING: Lakaskia soils are on nearly level or slightly depressional areas of lacustrine terraces and lake plains that are late Wisconsin age. Slope ranges from 0 to 2 percent. Lakaskia soils formed in loess and lacustrine sediments or a mixture of these materials. Some areas are subject to shallow inudation during rare, extremely high flood events. Near the type location these soils are protected by the Corps of Engineers dam and lake at Carlyle, but are in a position that flooding is possible. Mean annual air temperature is 54 to 57 degrees F., mean annual soil temperature is 56 to 59 degrees F., mean annual precipitation 36 to 40 inches, frost-free period is 180 to 200 days, and elevation is 370 to 450 feet above mean sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bartelso, Birds, Hurst, Okaw, Petrolia, and Wagner series. The somewhat poorly drained Bartelso soils form a hydrosequence with the Lakaskia soils. They are on slightly higher landform positions nearby. The poorly drained Birds and Petrolia soils are on flood plains below the Lakaskia soils. Hurst and Okaw soils have ochric epipedons and are the Alfisol equivalents of Bartelso and Lakaskia soils, respectively. The poorly drained Wagner soils have a moderately dark surface layer and they form a biosequence with the Okaw and Lakaskia soils.
DRAINAGE AND PERMEABILITY: Poorly drained and slow permeability. The potential for surface water runoff is negligble. In drained areas, depth to an intermittent perched high water table is 0.5 foot above the surface to 1.0 foot below from December to April in most years.
USE AND VEGETATION: Most areas are cropped to corn, milo, soybeans, and small grain. Native vegetation is mixed tall and short prairie grasses.
DISTRIBUTION AND EXTENT: Southern Illinois; extent is small, and mainly in MLRA(s) 113 and 114.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Clinton County, Illinois, 1991.
REMARKS: Diagnostic horizons and features in this pedon include: Mollic epipedon - from the surface of the soil to a depth of approximately 13 inches (Ap and A horizons). Argillic horizon - from a depth of approximately 13 to 60 inches (Btg1, Btg2, 2Btkg1, 2Btkg2, and 2BCtkg horizons). Aquic conditions - periodic saturation and reduction, indicated by redoximorphic features throughout the soil. The boundary between the loess and the lacustrine sediments is often difficult to detect from field observations.
The typical pedon was resampled and described to 80 inches for this revision.