LOCATION CREIGHTON WY+NEEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Aridic Haplustolls
TYPIFYING PEDON: Creighton very fine sandy loam, grassland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 6 inches; grayish brown (10YR 5/2) very fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate very fine granular structure; soft, very friable, nonsticky and nonplastic; many fine roots; neutral (pH 7.2); clear smooth boundary. (4 to 8 inches thick)
A2--6 to 10 inches; grayish brown (10YR 5/2) very fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure parting to moderate fine granular; hard, very friable, nonsticky and nonplastic; many fine roots; neutral (pH 7.2); clear smooth boundary. (3 to 7 inches thick)
Bw--10 to 20 inches; brown (10YR 5/3) very fine sandy loam, brown (10YR 4/3) moist; moderate coarse prismatic structure parting to moderate coarse subangular blocky; hard, very friable; slightly sticky and slightly plastic; common fine and medium roots; slightly alkaline (pH 7.6); gradual wavy boundary. (8 to 15 inches thick)
Bk--20 to 60 inches; very pale brown (10YR 7/2) very fine sandy loam, brown (10YR 5/3) moist; massive; hard, very friable; few fine roots; strongly effervescent, calcium carbonate as soft masses, thin seams and streaks; moderately alkaline (pH 8.2).
TYPE LOCATION: Goshen County, Wyoming; approximately the center of sec. 21, T.19N., R.64W. 41 degrees 36 minutes 2 seconds north latitude and 104 degrees 32 minutes 46 seconds west longitude.
RANGE IN CHARACTERISTICS: The mollic epipedon is 7 to 19 inches thick. Depth to accumulations of secondary calcium carbonate ranges from 6 to about 20 inches.
The particle size control section is typically very fine sandy loam with clay ranging from 5 to 18 percent, silt from 10 to 50 percent, and sand from 40 to 75 percent with more than 15 percent but less than 35 percent being fine or coarser sand. Rock fragments range from 0 to 15 percent. Average annual soil temperature ranges from 47 degrees to 58 degrees F.
The A horizon has hue of 5Y through 7.5YR, value of 4 or 5 dry and 2 or 3 moist, and chroma of 2 or 3. Reaction is slightly acid through slightly alkaline.
The Bw horizon has hue of 5Y through 7.5YR, value of 5 through 7 dry and 3 through 6 moist, and chroma of 2 through 6. Reaction is neutral or slightly alkaline.
The Bk or C horizon has hue of 5Y through 7.5YR. It is very fine sandy loam or loam with less than 18 percent clay. Reaction is moderately to strongly alkaline. Calcium carbonate equivalent ranges from 3 to 14 percent. Bk horizons have less than a 5 percent increase in calcium carbonate equivalent over an underlying horizon.
COMPETING SERIES: These are the Alice, Blanche, Busher, Chappell, Jayem, Phiferson, Stapleton, and Unaweep series. Alice soils have more than 35 percent fine or coarser sand in the particle size control section. Blanche and Phiferson soils are moderately deep. Busher soils have a paralithic contact at a depth of 40 to 60 inches. Chappell soils have a lithologic discontinuity at a depth of 20 to 40 inches. Jayem and Stapleton soils are noncalcareous throughout. Unaweep soils have hue of 5YR or redder.
GEOGRAPHIC SETTING: The Creighton soils are on gently to moderately sloping alluvial fans,hillslopes and valley fills. Slopes range from 0 to 20 percent. The soil formed in alluvium derived from fine grained sandstone, siltstones and limestones. The average annual precipitation is about 16 inches with peak periods of precipitation occurring in the spring months. The average annual temperature is about 49 degrees F. The average frost free period is 110 to 130 days.
PRINCIPAL ASSOCIATED SOILS: These are the Hargreave and Rosebud soils. Both of these soils have argillic horizons and have bedrock at depths of less than 40 inches.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used for native pasture or for dry or irrigated cropland. Principal native plants are blue grama, western wheat, needleandthread, big sagebrush, and cactus.
DISTRIBUTION AND EXTENT: Colorado, Wyoming, and Nebraska. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Goshen County, Wyoming, 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 10 inches (A1,A2)
Cambic horizon - 10 to 20 inches (Bw)
MLRR- G
SIR- WY0174