LOCATION SHIRK WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Haplustolls
TYPICAL PEDON:
Shirk clay loam in an area of native range (Colors are for dry soil unless otherwise stated).
A--0 to 8 centimeters (0 to 3 inches); grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate, medium, granular structure; soft, friable; many roots; neutral; clear, smooth boundary.
Bw--8 to 36 centimeters (3 to 14 inches); grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; weak, moderate to coarse, angular blocky structure; slightly hard, firm, slightly sticky, and slightly plastic; few roots; neutral; clear, smooth boundary.
Bt--36 to 51 centimeters (14 to 20 inches); grayish brown (2.5YR 5/2) clay loam, dark brown (10YR 4/3) moist; weak, fine to medium, angular blocky structure; very few faint clay films; slightly hard, firm, sticky, and plastic; few roots; neutral; clear, smooth boundary.
C--51 to 66 centimeters (20 to 26 inches); grayish brown (10YR 5/2) channery clay loam, dark yellowish brown (10YR 3/4) moist; structureless; slightly hard, firm, sticky, and plastic; many fine and few medium chips of platy shale, 1.5 to 3 centimeters (0.5 to 1 inch) in diameter; neutral; clear, smooth boundary.
R--66 centimeters (26 inches); fractured, non-calcareous, platy shale.
TYPE LOCATION: Johnson County, Wyoming in an area of Wormser-Shirk association, in the NE of the SE of section 9, T. 41 N., R. 81W.
RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon: 18 to 36 centimeters (about 7 to 14 inches).
Depth to bedrock: 50 to 100 centimeters (about 20 to 40 inches).
A horizon:
Hue: 10YR to 2.5Y
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3
Organic matter content: 1 to 3 percent
Texture (less than 2 mm): Loam or clay loam
Clay content 27 to 30 percent
Content of rock fragments: 0 to 20 percent channers
Electrical conductivity (mmhos/cm): 0 to 2
Reaction: pH 6.1 to 7.8
Bw horizon:
Hue: 10YR to 2.5Y
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 to 4
Organic matter content: 1 to 3 percent
Texture (less than 2 mm): Loam or clay loam
Clay content 20 to 34 percent
Content of rock fragments: 0 to 20 percent channers
Electrical conductivity (mmhos/cm): 0 to 2
Reaction: pH 6.6 to 7.8
Bt horizon:
Hue: 10YR to 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 4
Organic matter content: 0.5 to 1 percent
Texture (less than 2 mm): Loam or clay loam
Clay content 20 to 34 percent
Content of rock fragments: 0 to 20 percent channers
Electrical conductivity (mmhos/cm): 0 to 2
Reaction: pH 6.6 to 7.8
C horizon:
Hue: 10YR to 2.5Y
Value: 5 or 6 dry, 3 to 5 moist
Chroma: 2 to 4
Organic matter content: 0.5 to 1 percent
Texture (less than 2 mm): Loam or clay loam
Clay content 20 to 34 percent
Content of rock fragments: 10 to 25 percent channers
Electrical conductivity (mmhos/cm): 0 to 2
Reaction: pH 6.6 to 7.8
COMPETING SERIES: These are the
Capps,
Chugter,
Deacon,
Shore,
Tejana,
Valle series.
Capps soils do not have a lithic contact between 50 and 100 centimeters (about 20 and 40 inches).
Chugter soils do not have a lithic contact between 50 and 100 centimeters (about 20 and 40 inches).
Deacon soils do not have a lithic contact between 50 and 100 centimeters (about 20 and 40 inches).
Shore soils do not have a lithic contact between 50 and 100 centimeters (about 20 and 40 inches).
Tejana soils do not have a lithic contact between 50 and 100 centimeters (about 20 and 40 inches).
Valle soils do not have a lithic contact between 50 and 100 centimeters (about 20 and 40 inches).
GEOGRAPHIC SETTING:
Landscape: Sedimentary plains
Landform: Hills
Parent material: Residuum weathered from non-calcareous shale
Elevation: 1,524 to 1,676 meters (about 5,000 to 5,500 feet)
Mean annual temperature: 7 to 9 degrees Celsius (about 45 to 48 degrees Fahrenheit)
Mean annual precipitation: 254 to 356 millimeters (about 10 to 14 inches)
Frost free days: 110 to 125 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Moret and Wormser soils. Moret soils are shallow to a lithic contact and on higher landform positions. Wormser soils have a fine textured particle-size class, are moderately deep to a paralithic contact, and on lower landform positions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderately high saturated hydraulic conductivity
USE AND VEGETATION: These soils are principally used for range and wildlife habitat. The vegetation is western wheatgrass and big sagebrush.
DISTRIBUTION AND EXTENT: Northeastern Wyoming. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Johnson County, Wyoming; 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 36 centimeters (0 to 14 inches), A and Bw horizons.
Particle-size control section: 25 to 66 centimeters (10 to 26 inches).
Cambic horizon: 36 to 51 centimeters (14 to 20 inches), Bt horizon. The Bt horizon does not meet the criteria for an argillic horizon.
Lithic contact: 66 centimeters (26 inches), R horizon.
Moisture regime: Ustic moisture regime bordering on aridic.
Temperature regime: Mesic temperature regime.