LOCATION BLACKHALL WY+CO MT SD UTEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, calcareous, frigid, shallow Ustic Torriorthents
TYPICAL PEDON: Blackhall fine sandy loam-rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; light yellowish brown (2.5Y 6/3) fine sandy loam, olive brown (2.5Y 4/3) moist; moderate very fine granular structure; soft, very friable; few soft sandstone fragments; slightly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (2 to 8 inches thick)
C--4 to 12 inches; pale yellow (2.5Y 7/3) fine sandy loam, light yellowish brown (2.5Y 6/3) moist; massive; slightly hard, very friable, few soft sandstone chips; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (3 to 18 inches thick)
Cr--12 to 20 inches; soft, strongly effervescent sandstone.
TYPE LOCATION: Carbon County, Wyoming; approximately 700 feet east and 200 feet south of the northwest corner of sec. 21. T. 17 N., R. 83 W.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact and bedrock is 6 to 20 inches. The mean annual soil temperature is about 40 to 45 degrees F., and the mean summer soil temperature is about 59 to 66 degrees F. The control section averages 5 to 18 percent clay and has more than 35 percent fine or coarser sand. Sandstone fragments range from 0 to 35 percent and are less than 3 inches in diameter. Textures are sandy loam, fine sandy loam, or very fine sandy loam. The moisture control section is usually dry, but is moist in April, May, and early June..
The A horizon has hue of 2.5Y or 10YR, value of 5 or 7 dry, 3 through 6 moist, and chroma of 2 through 6. It is neutral through moderately alkaline.
The C horizon has hue of 5Y through 10YR, value of 5 through 7 dry, 3 through 6 moist, and chroma of 2 through 6. It is mildly through strongly alkaline. A Bk or Bw horizon may be present but is nondiagnostic.
COMPETING SERIES: These are the Blazon, Byrnie, Cabbart, Niler(T), Seaverson, and Thermopolis series. Blazon, Cabbart, and Niler soils average more than 18 percent clay in the particle-size control section. Byrnie and Thermopolis soils have hue of 5YR through 10R. Seaverson soils have over 15 percent exchangeable sodium throughout.
GEOGRAPHIC SETTING: Blackhall soils are on hills and ridges Slopes are 3 to 65 percent. These soils formed in colluvium, alluvium and residuum weathered from sandstone. Elevations are 4200 to 7,800 feet. The mean annual precipitation ranges from 10 to 14 inches of which half falls as snow and rain during April, May, and June. The mean annual temperature is about 39 to 45 degrees F., and the mean summer temperature is 58 to 65 degrees F. The frost-free season is 60 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carmody and Ryan Park soils. Carmody soils have a paralithic contact at depths of 20 to 40 inches. Ryan Park soils have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium or rapid runoff; moderate or moderately rapid permeability.
USE AND VEGETATION: These soils are used as rangeland. Native vegetation is black sagebrush, needleandthread, sandberg bluegrass, Indian ricegrass, threadleaf sedge, and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Intermountain basins and plains of Wyoming, Colorado, Montana and South Dakota. The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Butte County, South Dakota; 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--0 to 4 inches (A)
Ustic subgroup - Aridic soil moisture regime that borders Ustic.
Paralithic contact--12 inches (Cr)
SIRs'- WY0223, WY0723, WY0889, WY0928