LOCATION EMIGRANT WY+SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Aridic Argiustolls
TYPICAL PEDON: Emigrant loam-rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 5 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many fine roots; few fine tubular and many very fine interstitial pores; neutral (pH 7.0); clear smooth boundary. (3 to 6 inches thick)
Bt1--5 to 8 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; weak medium prismatic structure parting to moderate fine subangular blocky; hard, friable, sticky and plastic; many distinct clay films on faces of peds; neutral (pH 7.0); clear smooth boundary. (0 to 4 inches thick)
Bt2--8 to 20 inches; grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; hard, firm, sticky and plastic; many prominent clay films on faces of peds; slightly alkaline (pH 7.6); clear smooth boundary. (10 to 20 inches thick)
Btk--20 to 26 inches; grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; very hard, firm, sticky and plastic; common distinct clay films on faces of peds; strongly effervescent, few fine threads and soft rounded masses of calcium carbonate; moderately alkaline (pH 8.2); gradual wavy boundary. (4 to 6 inches thick)
Bk--26 to 32 inches; light gray (2.5Y 7/2) clay, grayish brown (2.5Y 5/2) moist; massive; hard, firm, sticky and plastic; strongly effervescent, common soft masses of calcium carbonates; moderately alkaline (pH 8.2) abrupt wavy boundary. (3 to 10 inches thick)
Cr--32 inches; amorphous, yellowish slightly calcareous cretaceous shale.
TYPE LOCATION: Crook County, Wyoming; about 5 miles south of Colony; NW corner NW1/4 SW1/4 sec. 36, T.56N., R.61W.
Middle Creek Butte quadrangle, 44 degrees 48 minutes 7 seconds north latitude and 104 degrees 7 minutes 17 seconds west longitude.
RANGE IN CHARACTERISTICS: Depth to bedrock is typically 28 to 35 inches but ranges from 20 to 40 inches. Depth to horizons of calcium carbonate accumulation is 10 to 23 inches. Rock fragments are typically less than 5 percent but range from 0 to 15 percent in the series control section.
The A horizon has hue of 10YR or 2.5Y, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3 dry or moist. Reaction is normally neutral, but ranges from slightly acid to slightly alkaline.
The Bt horizon has hue of 10YR or 2.5Y, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3. The mollic colors do not extend below a depth of 16 inches. This horizon is clay or clay loam; clay ranges from 35 to 50 percent, silt from 5 to 40 percent, and sand from 20 to 45 percent with more than 15 percent being fine sand or coarser. Reaction is normally slightly alkaline but ranges from neutral to moderately alkaline.
The Btk horizon has hue of 10YR or 2.5Y, value of 5 or 6 dry, 4 or 5 moist, and chroma of 2 through 4. It is clay or clay loam, with clay, silt and sand ranges the same as the Bt horizon. This horizon has accumulations of calcium carbonate occurring as threads, soft rounded masses, concretions, and is disseminated throughout the matrix.
The Bk horizon has hue of 10YR or 2.5Y, value of 6 or 7 dry, 4 through 6 moist, and chroma of 2 through 4. It is clay loam or clay. This horizon contains from 6 to 14 percent calcium carbonate in the form of soft masses, and nodules, and disseminated throughout.
The Cr horizon is primarily calcareous cretaceous shale which may be interbedded with calcareous loamstones or calcareous fine grained sandstone.
COMPETING SERIES: These are the Ashfork, Blackpipe, Boneek, Boquillas, Chapin, Collbran, Huggins, Kube, Leyden, Loma, Nuncho, Nunn, Querc, Rednun, Richfield, Ryus, Savo, Showlow, Sofia, Standley, Thunderbird, Torreon, and Wormser series. Ashfork, Chapin, Thunderbird and Wormser soils have a lithic contact at a depth of 20 to 40 inches. Blackpipe, Huggins, Loma, Richfield, and Savo soils have less than 15 percent fine sand or coarser. Loma and Savo soils also lack a paralithic contact above a depth of 40 inches. Boneek, Collbran, Kube, Nunn, Rednun, Ryus, Sofia, and Torreon soils lack a paralithic contact above a depth of 40 inches.
GEOGRAPHIC SETTING: Emigrant soils are on rock-controlled pediment toeslopes and footslopes. Slopes range from 0 to 15 percent. The soils formed in fine textured, calcareous slopewash alluvium and residuum. Elevations range from 2600 to 5,400 feet. Mean annual temperature ranges from 45 degrees F. to 54 degrees F. mean annual precipitation ranges from 12 to 18 inches. Frost-free season is 110 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Razor, Renohill, and Samsil soils and the competing Nunn soils. Razor soils lack a mollic epipedon and argillic horizon; they occur on more sloping parts of the landscape. Renohill soils lack a mollic epipedon and occur on drier positions. Samsil soils are shallow and lack a mollic epipedon and an argillic horizon; they occur on ridgecrests and near rock outcrops.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: Domestic livestock grazing on rangeland. Vegetation is mainly western wheatgrass, blue grama, green needlegrass and needleandthread. Small areas are dryland farmed under a crop-fallow system.
DISTRIBUTION AND EXTENT: Northeastern and central Wyoming and Western South Dakota. It is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Crook County, Wyoming, 1978.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
mollic epipedon - 0 to 8 inches (A,Bt1)
argillic horizon - 5 to 26 inches (Bt1,Bt2,Btk)
paralithic contact - 32 inches (Cr)
LRR- G
SIR's- WY0422, WY1258