LOCATION SONSAC MO+ILEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, mixed, active, mesic Typic Hapludalfs
TYPICAL PEDON: Sonsac very cobbly silt loam - On a north facing 11 percent slope at an elevation of 965 feet. (Colors are for moist soil unless otherwise stated.)
A--0 to 3 inches; very dark grayish brown (10YR 3/2) very cobbly silt loam; grayish brown (10YR 5/2) dry; moderate fine granular structure; very friable; many fine roots; few fine interstitial and tubular pores; 10 percent chert gravel, 35 percent chert cobbles, 5 percent chert stones; moderately alkaline (pH 8.0); abrupt smooth boundary.(1 to 7 inches thick)
BA--3 to 6 inches; strong brown (7.5YR 4/6), and very dark grayish brown (10YR 3/2) very cobbly silt loam; light brown (7.5YR 6/3), and grayish brown (10YR 5/2) dry; weak fine subangular blocky structure; friable; many fine roots; few fine interstitial and tubular pores; 15 percent chert gravel, 35 percent chert cobbles, 5 percent chert stones; neutral (pH 7.0); abrupt smooth boundary.(0 to 10 inches thick)
Bt1--6 to 9 inches; brown (10YR 4/3) very cobbly silty clay loam; moderate fine subangular blocky structure; firm; common fine roots; common faint clay films on faces of peds; 10 percent chert gravel, 40 percent chert cobbles and 5 percent chert stones; slightly acid (pH 6.5); clear smooth boundary.(3 to 10 inches thick)
2Bt2--9 to 15 inches; reddish brown (5YR 4/4) extremely cobbly clay; moderate fine subangular blocky structure; firm; common fine roots; common distinct clay films on faces of peds; 15 percent chert gravel, 45 percent chert cobbles and 5 percent chert stones; slightly acid (pH 6.5); clear wavy boundary.
2Bt3--15 to 21 inches; dark red (2.5YR 3/6) very cobbly clay; moderate fine angular blocky structure; firm; few fine roots; many distinct clay films on faces of peds; few fine rounded masses of iron accumulation; 5 percent chert gravel, 45 percent chert cobbles and 5 percent stones; slightly acid (pH 6.5); gradual wavy boundary.
2Bt4--21 to 31 inches; yellowish red (5YR 4/6) very cobbly clay; moderate fine and medium angular blocky structure; firm; few very fine and fine roots; common distinct clay films on faces of peds; few fine irregular masses of iron accumulation; 10 percent chert gravel, 30 percent chert cobbles and 5 percent chert stones; neutral (pH 6.8); clear wavy boundary. (combined thickness of the 2Bt horizon ranges from 20 to 35 inches thick)
2R--31 inches; limestone
TYPE LOCATION: Dade County, Missouri; about 8 miles north of Greenfield, west off H highway; 1900 ft. west of and 2000 ft. north of the southeast corner of section 17, T. 32 N., R. 26 W.; USGS Crisp quadrangle; lat. 37 degrees 30 minutes 37 seconds N. and 93 degrees 48 minutes 30 seconds W. NAD 27
RANGE IN CHARACTERISTICS:
Depth to Bedrock: 20 to 40 inches
Surface Cover: 0 to 3 percent stones or rock outcrop
Particle size control section: averages 35 to 60 percent rock fragments; and 35 to 50 percent clay.
A or Ap horizon
Hue: 7.5YR or 10YR
Value: 3 or 4 (where the surface layer is 6 or more inches thick, the value dry is 6)
Chroma: 2 or 3
Fine earth: silt loam (may be silty clay loam where eroded)
Total rock fragments: 0 to 70 percent; 0 to 70 percent gravel, 0 to 40 percent cobbles, 0 to 40 percent flags, and 0 to 10 percent stones
Reaction: strongly acid to moderately alkaline
E horizon (where present)
Hue: 10YR
Value: 5 or 6
Chroma: 3 to 6
Fine earth: silt loam
Total rock fragments: 2 to 80 percent; 2 to 65 percent gravel, 0 to 40 percent cobbles, 0 to 40 percent flags, and 0 to 10 percent stones
Reaction: strongly acid to slightly acid
BA or BE horizon (where present)
Hue: 7.5YR or 10YR
Value: 3 or 4
Chroma: 2 to 6
Fine earth: silt loam
Total rock fragments: 2 to 75 percent; 2 to 60 percent gravel, 0 to 50 percent cobbles, 0 to 50 percent flags, and 0 to 8 percent stones
Reaction: strongly acid to neutral
Bt horizon
Hue: 7.5YR or 10YR
Value: 3 to 5
Chroma: 3 to 6
Fine earth: silt loam, loam, clay loam, silty clay loam, or silty clay
Total rock fragments: 5 to 80 percent; 5 to 80 percent gravel, 0 to 55 percent cobbles, 0 to 40 percent flags, 0 to 10 percent stones
Reaction: strongly acid to moderately alkaline
2Bt horizon
Hue: 2.5YR to 2.5Y
Value: 3 to 8
Chroma: 2 to 8
Fine earth: silty clay or clay
Total rock fragments: 5 to 80 percent; 5 to 80 percent gravel, 0 to 45 percent cobbles, 0 to 45 percent flags, and 0 to 30 percent stones
Reaction: strongly acid to moderately alkaline
Note: 2.5Y hue and 2 chroma colors are relict and do not indicate wetness.
Some pedons have a 2BC, 2C, or 2Cr horizon that is highly variable in color and texture.
COMPETING SERIES: This is the Gobbler series. Gobbler soils have a lithic contact from 40 to 60 inches.
GEOGRAPHIC SETTING: Sonsac soils are on moderately sloping to steep upland side slopes. They have formed colluvium and the underlying residuum derived from limestone that has a high chert content and is primarily Ordovician or Mississippian in age. Slopes range from 5 to 70 percent. Mean annual temperature ranges from 54 to 57 degrees F, and mean annual precipitation ranges from 36 to 44 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alsup, Goss, Moko and Wilderness series. Alsup soils are in the fine family class and are deep to a paralithic contact. Goss and Wilderness soils are very deep to a lithic contact. Wilderness soils have a fragipan. Moko soils are very shallow and shallow to a lithic contact. These soils are on similar landscape positionsas the Sonsac soils.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. The saturated hydraulic conductivity is moderately high. The surface runoff index is medium to high.
USE AND VEGETATION: Most areas are in pasture or woodland. Native vegetation was mixed hardwoods.
DISTRIBUTION AND EXTENT: The Ozark Highland (MLRA 116A) and the Springfield Plain (MLRA 116B) areas in Missouri and the River Hills (MLRA 115) area of southeast Missouri and southwest Illinois. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Dade County, Missouri, 1996.
REMARKS: Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the surface of the soil to a depth of 6 inches (A and BA horizons);
argillic horizon - the zone from approximately 6 to 31 inches (Bt1, 2Bt2, 2Bt3 and 2Bt4 horizons).
ADDITIONAL DATA: University of Missouri soil characterization lab number M92057060.