LOCATION THENIPEL COEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Ustic Haplocambids
TYPICAL PEDON: Thenipel silt loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; pale brown (10YR 6/3) silt loam, dark yellowish brown (10YR 3/4) moist; weak fine granular structure; slightly hard, friable, sticky and plastic; violently effervescent; moderately alkaline (pH 8.0); gradual smooth boundary. (2 to 3 inches thick)
Bw1--2 to 13 inches; light yellowish brown (10YR 6/4) silty clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, sticky and plastic; violently effervescent; moderately alkaline (pH 8.2); gradual smooth boundary. (10 to 15 inches thick)
Bw2--13 to 25 inches; very pale brown (10YR 7/4) silty clay loam, dark yellowish brown (10YR 4/6) moist; moderate medium prismatic structure parting to weak fine angular blocky; slightly hard, friable, sticky and plastic; 5 percent channery fragments; violently effervescent; moderately alkaline (pH 8.4); gradual smooth boundary. (8 to 13 inches thick)
Bk1--25 to 37 inches; pale yellow (2.5Y 7/4) silty clay loam, yellowish brown (10YR 5/6) moist; weak medium subangular blocky structure; slightly hard, friable, sticky and plastic; 5 percent channery fragments; few fine seams of segregated calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); gradual smooth boundary. (10 to 15 inches thick)
Bk2--37 to 60 inches; pale yellow (2.5Y 7/4) silty clay loam, yellowish brown (10YR 5/6) moist; weak medium subangular blocky structure; slightly hard, friable, sticky and plastic; 5 percent channery fragments; few fine seams of segregated calcium carbonate; violently effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Moffat County, Colorado, approximately 11 miles south of Powderwash, about 1,700 feet west and 2,200 feet north of the southeast corner of Sec. 18, T. 10 N., R. 98 W.; 40 degrees, 49 minutes, 29 seconds north latitude; 108 degrees, 26 minutes, 43 seconds west longitude.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 44 to 46 degrees F., and mean summer soil temperature ranges 61 to 64 degrees F. The soil is calcareous throughout. The control section averages 20 to 30 percent clay, 50 to 65 percent silt and 10 to 25 percent sand. Content of rock fragments in the control section averages 0 to 10 percent. Electrical conductivity of the pedon is less than 2 mmho/cm. SAR values are less than 13 throughout.
The A horizon has a hue of 10YR or 2.5Y, value of 5 or 6 dry, 3 or 4 moist, and a chroma of 3 or 4.
The Bw horizon has a hue of 10YR or 2.5Y, value of 6 or 7 dry, 4 through 6 moist, and a chroma of 4 through 6. Content of rock fragments ranges from 0 to 5 percent. Texture is silt loam, silty clay loam, or loam.
The Bk1 horizon has a hue of 10YR or 2.5Y, value of 6 or 7 dry, 5 or 6 moist, and a chroma of 4 through 6. Content of rock fragments ranges from 0 to 5 percent. Texture is silt loam, silty clay loam, or loam.
The Bk2 horizon has a hue of 10YR or 2.5Y, value of 6 or 7 dry, 5 or 6 moist, and a chroma of 4 through 6. Content of rock fragments ranges from 5 to 15 percent. Texture is silt loam, silty clay loam, or loam.
COMPETING SERIES: These are the Alona (MT), Cambeth (MT), Chalkcreek (WY), Lonna (MT), and Rahworth (MT) series. Alona soils are very strongly alkaline, have an SAR of 13 or more at depths as shallow as 6 inches, EC of 2 or more at depths as shallow as 11 inches, and have salt accumulations at 11 inches as well. Cambeth and Lonna soils have a mean summer soil temperature greater than 64 degrees F. Chalkcreek soils contain greater than 30 percent very fine sand and a high percentage of glass shards. Rahworth soils are extremely saline in the lower part of the subsoil. Lonna soils have EC of 2 or more between 21 to 60 inches.
GEOGRAPHIC SETTING: Thenipel soils are on footslopes, toeslopes, and fans. Slopes range from 3 to 12 percent. The soil formed in alluvium and loess derived from siltstone. Elevation ranges from 6,100 to 7,200 feet. Mean annual precipitation ranges from 9 to 11 inches, but additional moisture is received in the form of snow drifting upon the soil. The mean annual temperature ranges from 42 to 45 degrees F. The frost-free period is 75 to 95 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fenster, Haterton, and Piezon soils. Fenster soils do not have a cambic horizon and have a moisture control section that is drier for a longer period. Haterton soils are shallow to a lithic contact. Piezon soils are moderately deep to a paralithic contact and have a calcic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. Native vegetation is western wheatgrass, Nevada bluegrass, prairie junegrass, bottlebrush squirreltail, and Wyoming big sagebrush.
DISTRIBUTION AND EXTENT: These soils occur in northwestern Colorado. The series is of small extent. Total area is about 1,800 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Moffat County (Moffat County Area), Colorado, 1991.
REMARKS: Diagnostic horizons and features recognized in this pedon are: the ochric epipedon-the zone from 0 to 2 inches; the cambic horizon-the zone from 2 to 25 inches; Borollic feature - organic carbon content and the soil temperature regime meets the requirements of Borollic. Last updated by the state 12/90.