LOCATION SANDWASH COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, carbonatic, frigid Ustic Haplocalcids
TYPICAL PEDON: Sandwash loam - rangeland. (Colors are for air dry soil unless otherwise noted).
A--O to 2 inches ; very pale brown (10YR 7/3) loam, brown (10YR 4/3) moist; moderate thin platy structure; slightly hard, friable, slightly sticky, slightly plastic; violently effervescent, moderately alkaline (pH 8.2); abrupt smooth boundary. (1 to 4 inches thick)
Bw--2 to 9 inches; light yellowish brown (10YR 6/4) loam; dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; violently effervescent, moderately alkaline (pH 8.0); clear smooth boundary. (0 to 12 inches thick)
Bk--9 to 16 inches; very pale brown (10YR 7/4) loam; yellowish brown (10YR 5/4) moist; massive; slightly hard, friable, slightly sticky, slightly plastic; 5 percent pebbles, 35 percent disseminated calcium carbonate equivalent; violently effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (5 to 10 inches thick)
2Bk--16 to 22 inches; very pale brown (10YR 7/4) extremely cobbly loam, yellowish brown (10YR 5/4) moist; massive; soft, very friable, slightly sticky, slightly plastic; 70 percent cobble, 5 percent pebbles, 70 percent calcium carbonate equivalent; violently effervescent; calcium carbonate disseminated and as many thick pendants occurring on the undersides of the cobbles; moderately alkaline (pH 8.2); abrupt wavy boundary (5 to 22 inches thick)
R--22 inches, hard fractured limestone.
TYPE LOCATION: Moffat County, Colorado; 11 miles southwest of Powderwash, Colorado; 1,300 feet south and 1,300 feet east of the northwest corner of Sec. 33, T. 10 N., R. 98 W. Latitude 40 degrees, 47 minutes, 11 seconds north. Longitude 108 degrees, 24 minutes, 52 seconds west.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 44 to 47 degrees F. A lithic contact is at a depth of 20 to 40 inches. The particle-size control section averages 35 to 60 percent rock fragments. Rock fragments consist of angular cobbles and channers. The soil is typically calcareous to the surface. Some pedons may be leached to a depth of 5 inches, but upon mixing the upper 7 inches all parts are calcareous. Depth to the calcic horizon is 4 to 15 inches. Calcium carbonate equivalent of the fine earth fraction averages 40 to 60 percent in the particle-size control section.
The A horizon has a hue of 2.5Y through 7.5YR, value of 4 through 7, and 3 through 6 moist, and chroma of 2 through 4.
The Bw and Bk horizons have a hue of 2.5Y through 7.5YR, value of 5 through 7, and 3 through 6 moist, and chroma of 2 through 4. Rock fragments range from 5 to 35 percent and are 1/2 to 3 inches in diameter. Texture is channery loam, loam, or clay loam. The Bw is absent in some pedons.
The 2Bk horizon has a hue of 2.5Y through 7.5YR, value of 6 through 8, and 5 through 7 moist, and chroma of 3 through 5. Rock fragments are 35 to 65 percent and are 1-1/2 to 6 inches in diameter. Reaction is moderately or strongly alkaline. Textures are extremely cobbly loam or clay loam or extremely channery loam or very cobbly or very channery loam.
COMPETING SERIES: There are no competing series. Similar and related soils include Dera (T), Garita, and Tusayan. Dera soils have mesic temperatures. Tusayan soils have mesic soil temperatures and are in slightly more moist climates, Garita soils are deep and have mixed mineralogy.
GEOGRAPHIC SETTING: Sandwash series are on hillsides and plateaus. Slopes are 0 to 15 percent. The soil formed in eolian deposits and residuum from hard fractured limestone and sandstone. Mean annual temperature is 42 to 46 degrees F., the mean summer temperature is 62 to 67 degrees F., and the mean annual precipitation is 7 to 11 inches. Frost-free period is 75 to 95 days. Elevation is 6,000 to 7,300 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Langspring and Baston soils. Langspring soils are deep, non-skeletal with mixed mineralogy. Baston soils are fine textured soils with natric horizons.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Most areas of Sandwash soils are used for livestock grazing and wildlife habitat. Native vegetation is big sagebrush, shadscale, Indian ricegrass, and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: Sandwash soils are of small extent and occur in the north central part of Moffat County, Colorado. Approximately 3,600 acres are currently classified.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Moffat County (Moffat County Area), Colorado, 1991.
REMARKS: Series name is coined from the Sandwash Basin where this soil occurs. Diagnostic features in this soil is a calcic horizon from 9 to 22 inches. Last updated by the state 12/90.