LOCATION KARNAK                  IL+KY

Established Series
WMM/Rev. MDJ/JRT
03/2015

KARNAK SERIES

TAXONOMIC CLASS: Fine, smectitic, nonacid, mesic Vertic Endoaquepts

TYPICAL PEDON: Karnak silty clay - in a cultivated field. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 13 centimeters (0 to 5 inches); very dark grayish brown (10YR 3/2) silty clay, gray (10YR 6/1) and light brownish gray (10YR 6/2), dry; weak fine granular structure; firm; slightly acid (pH 6.1); abrupt smooth boundary.

Bg1--13 to 30 centimeters (5 to 12 inches); dark gray (5Y 4/1) silty clay; weak medium subangular blocky structure; firm; 15 percent faint dark gray (5Y 4/1) pressure faces on all faces of peds; 1 percent fine prominent cylindrical very weakly cemented yellowish brown (10YR 5/8) iron-manganese masses with diffuse boundaries on surfaces along root channels, 1 percent fine prominent cylindrical very weakly cemented yellowish brown (10YR 5/6) iron-manganese masses with diffuse boundaries on surfaces along root channels, and 5 percent fine distinct irregular olive (5Y 5/4) masses of oxidized iron with diffuse boundaries throughout; slightly acid (pH 6.1); clear smooth boundary.

Bg2--30 to 51 centimeters (12 to 20 inches); dark gray (5Y 4/1) silty clay; moderate fine prismatic structure parting to weak medium angular blocky; firm; 1 percent faint dark gray (5Y 4/1) clay films on surfaces along root channels and 5 percent faint dark gray (5Y 4/1) pressure faces on all faces of peds; 5 percent fine prominent spherical strongly cemented black (N 2.5/) iron-manganese concretions with sharp boundaries throughout, 5 percent fine prominent spherical strongly cemented yellowish brown (10YR 5/8) iron-manganese concretions with sharp boundaries throughout, and 10 percent fine prominent irregular light olive brown (2.5Y 5/6) masses of oxidized iron with diffuse boundaries throughout; slightly acid (pH 6.1); clear smooth boundary.

Bg3--51 to 84 centimeters (20 to 33 inches); dark gray (5Y 4/1) silty clay; moderate medium prismatic structure parting to weak fine angular blocky; firm; 1 percent faint dark gray (5Y 4/1) clay films on surfaces along root channels and 5 percent faint gray (N 5/) pressure faces on all faces of peds; 2 percent fine prominent irregular yellowish brown (10YR 5/6) masses of oxidized iron with diffuse boundaries throughout, 5 percent fine prominent spherical strongly cemented yellowish brown (10YR 5/8) iron-manganese concretions with sharp boundaries throughout, and 10 percent fine prominent irregular light olive brown (2.5Y 5/6) masses of oxidized iron with diffuse boundaries throughout; slightly acid (pH 6.3); clear smooth boundary.

Bg4--84 to 127 centimeters (33 to 50 inches); dark gray (N 4/) silty clay; weak fine prismatic structure parting to weak fine subangular blocky; firm; 1 percent faint gray (N 5/) clay films on surfaces along root channels and 5 percent faint gray (N 5/) pressure faces on all faces of peds; 2 percent fine prominent irregular light olive brown (2.5Y 5/6) masses of oxidized iron with diffuse boundaries throughout and 5 percent fine prominent irregular yellowish brown (10YR 5/6) masses of oxidized iron with diffuse boundaries throughout; slightly acid (pH 6.3); clear smooth boundary.

Cg--127 to 203 centimeters (50 to 80 inches); gray (5Y 5/1) silty clay loam; massive; very firm; 1 percent fine faint irregular light gray (5Y 7/1) iron depletions with diffuse boundaries throughout, 5 percent fine prominent irregular light olive brown (2.5Y 5/6) masses of oxidized iron with diffuse boundaries throughout, and 21 percent fine prominent irregular yellowish brown (10YR 5/8) masses of oxidized iron with diffuse boundaries throughout; slightly alkaline (pH 7.6).

TYPE LOCATION:
County: Massac
State: Illinois
USGS Quadrangle: Karnak
Latitude (Decimal Degrees, NAD 83): 37.2916720 north
Longitude (Decimal Degrees, NAD 83): 88.9253710 west
UTM Zone: 16
UTM Easting: 329336 meters
UTM Northing: 4128967 meters
Legal Description: SE , SE , SW , SW , of Section 18, T. 14 S., R. 3 E. of the third principal meridian.

RANGE IN CHARACTERISTICS:
Depth to the top of the Cambic horizon: 10 to 25 cm (4 to 10 inches)
Depth to the base of the Cambic horizon: 50 to 203 cm (20 to 80 inches)
Solum Thickness: 50 to 203 cm (20 to 80 inches)
Depth to Bedrock: Greater than 203 cm (80 inches)
Depth Class: Very Deep
Depth to Seasonal High Water Table: 0 to 25 cm (0 to 10 inches), November to May

Range of Individual Horizons:
Ap horizon, or A if it occurs:
Color--hue of 10YR through 5Y, value of 3 through 6, and chroma of 1 through 3; or is neutral with value of 3 through 6
Texture (fine-earth fraction)--silty clay, clay or silty clay loam
Redoximorphic features (if they occur)--Redoximorphic concentrations with hue of 5YR through 5Y, value of 4 through 7, and chroma of 3 through 8. Iron depletions with hue of 10YR through 5Y, value of 4 through 6, and chroma of 1 or 2; or neutral with value of 4 through 7
Reaction--slightly acid or moderately acid except where limed
Other features--Overwash phases include silt loam. Some pedons have thin O horizons on the soil surface.

Bg horizon, or Bgss and Btg if they occur:
Color--hue of 10YR through 5Y, value of 4 through 6, and chroma of 1 or 2, or is neutral with value of 4 through 6
Texture (fine-earth fraction)--silty clay, clay or silty clay loam
Redoximorphic features--Redoximorphic concentrations with hue of 5YR through 5Y, value of 4 through 7, and chroma of 3 to 8; or is neutral with value of 2.5. Iron depletions (where they occur) with hue of 10YR through 5Y, values of 4 through 6, chroma of 1 or 2, or is neutral with value of 4 through 6
Reaction--strongly acid to slightly alkaline
Other features--Some pedons have few clay films on ped surfaces. Slickensides occur in most pedons. The control section averages 40 to 60 percent clay.

BCg or similar transitional horizon (if it occurs)
Colors, textures, redoximorphic features, and reaction are similar to the Cg horizon

Cg horizon:
Color--hue of 10YR through 5Y, value of 4 through 6, and chroma of 1 or 2, or is neutral with value of 4 through 6
Texture (fine-earth fraction)--silty clay, clay or silty clay loam (some pedons are stratified with silt loam or loam)
Redoximorphic features--Redoximorphic concentrations with hue of 5YR through 5Y, value of 4 through 7, and chroma of 3 to 8. Iron depletions with hue of 10YR through 5Y, values of 4 through 7, chroma of 1 or 2, or is neutral with value of 4 through 6
Mottles (if they occur)--some pedons have inherent mottles with similar colors as the redoximorphic features.
Reaction--moderately acid to moderately alkaline

COMPETING SERIES:
Owego soils--have carbonates in the upper part of the control section.
Quenzer soils--formed in alluvium from granitic origin and occur where mean annual precipitation is about 250 millimeters (10 inches).

GEOGRAPHIC SETTING:
Landscape: river valley or lake plain
Landform: flood plain or terrace
MLRA(s): 113, 114, 115, 120A, 122, and 134
Geomorphic Component: flood plain in river valleys or on lake plains and less commonly terraces on lake plains
Parent Material: clayey non-acid slackwater alluvium
Slope: 0 to 2 percent
Elevation: 90 to 140 meters
Frost-free period: 170 to 230 days
Mean Annual Air Temperature: 12 to 15 degrees C.
Mean Annual Precipitation: 1000 to 1400 millimeters

GEOGRAPHICALLY ASSOCIATED SOILS:
Belknap soils--are on higher positions on the landscape, are somewhat poorly drained, have an acid reaction class, and have less than 18 percent clay in the control section.
Bonnie soils--average 18 to 27 percent clay in the control section and have an acid reaction class.
Birds soils--average 18 to 27 percent clay in the control section.
Cape soils--have an acid reaction class.
Darwin soils--have a dark surface.
Jacob soils--average more than 60 percent clay in the control section and have an acid reaction class.
Melvin soils--average 18 to 35 percent clay in the control section.
Petrolia soils--average 27 to 35 percent clay in the control section.
Piopolis soils--average 27 to 35 percent clay in the control section and have an acid reaction class.
Wakeland soils--are on higher positions on the landscape, are somewhat poorly drained, and average less than 18 percent in the control section.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage Class (Agricultural): Poorly and very poorly
Saturated Hydraulic Conductivity Class: Low or moderately low
Shrink-swell Potential: Very high
Flooding Frequency and Duration: Rare to frequent, brief to very long duration
Ponding Frequency and Duration: None to frequent, were ponding occurs, duration is brief to very long

USE AND VEGETATION:
Major Uses: Cropland and Forest
Dominant Vegetation: Corn and Soybeans where cultivated. Bald Cypress, Green Ash, Overcup Oak, Pin Oak, Silver Maple, Swamp White Oak, Swamp Chestnut Oak, Tupelo, and Willow Oak are common where forested. Some areas are swamps dominated by Buttonbush and Duckweed.

DISTRIBUTION AND EXTENT:
Distribution: Illinois and Kentucky
Extent: Moderate
Physiographic Division: Interior Plains
Physiographic Province: Interior Low Plateaus

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia

SERIES ESTABLISHED: Johnson County, Illinois, 1942.

REMARKS:
Diagnostic horizons and soil characteristics recognized in this pedon are:
ochric epipedon--the zone from 0 to 13 cm (5 inches) (Ap horizon)
cambic horizon--the zone from 13 to 127 cm (5 to 50 inches) (Bg horizons)
aquic moisture regime

Other soil features identified with this pedon:
Vertic subgroup based on linear extensibility greater than 6.0 cm between the surface and a depth of 100 cm
The 03/2015 revision converted to a semi-tabular format, expanded the Range in Characteristics to include reaction through slightly alkaline in the B horizons, and expanded the range of texture in the B horizon to include silty clay loam. The pedon description was updated to convert mottles to appropriate redoximorphic features.

ADDITIONAL DATA: Characterization data is available from the NSSL for the following pedons: 69IL-001-007

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National Cooperative Soil Survey
U.S.A.