LOCATION MITCH UTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Cumulic Haplustolls
TYPICAL PEDON: Mitch silt loam--rangeland. (Colors are for air dry soil unless otherwise stated.)
A1--0 to 2 inches; grayish brown (10YR 5/2) silt loam, dark brown (10YR 3/3) moist; weak thick platy structure that parts to weak fine granular; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; many fine intersitial pores; slightly calcareous; mildly alkaline (pH 7.8); abrupt smooth boundary. (1 to 3 inches thick)
A2--2 to 4 inches; dark grayish brown (10YR 4/2) loam, very grayish brown (10YR 3/2) moist; weak fine granular structure; very soft, very firable, slightly sticky and slightly plastic; common fine and very fine roots; many fine interstitial pores; slightly calcareous; mildly alkaline (pH 7.5); clear smooth boundary. (2 to 10 inches thick)
C1--4 to 26 inches; dark grayish brown (10YR 4/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure; that parts to weak fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; few very fine tubular pores; strongly calcareous; mildly alkaline (pH 7.5); clear wavy boundary. (10 to 30 inches thick)
C2--26 t0 29 inches--grayish brown (10YR 5/2) very fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak thick platy structure; soft, very friable; few medium and very fine roots; common fine interstitial pores; strongly calcareous; moderately alkaline (pH 8.0); clear wavy boundary. (0 to 4 inches thick)
C3--29 to 44 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine tubular pores; strongly calcareous; moderately alkaline (pH 8.0); gradual wavy boundary. (0 to 16 inches thick)
C4--44 to 60 inches; lightly brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; massive; soft, friable; few fine tubular and interstitial pores; 5 percent pebbles; violently calcareous; moderately alkaline (pH 8.2).
TYPE LOCATION: Garfield County, Utah; Prospect Creek, 500 feet north and 500 feet west of the S 1/4 corner of sec. 32, T. 33 S., R. 2 W.
RANGE IN CHARACTERISTICS: The mollic epipedon is 24 to 48 inches thick. The soil is mildly or moderately alkaline. The mean annual soil temperature is about 59 to 64 degrees F. The organic matter content decreases irregularly with increasing depth of remains about 0.5 percent of a depth of 50 inches. The soils are not dry for 60 consecutive days or more within 3 month period following the summer solstice in more than 7 out of 10 years in all parts of the soil between depths of 4 and 12 inches.
The A horizon has hue of 7.5YR or 10YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 1 to 3.
The C horizon has hue horizon has hue of 7.5YR or 10YR, value of 4 or 5 dry, 3 or 4 moist, and chroma of 1 to 3. It is stratified loam, silt loam, very fine sandy loam and clay loam with about 18 to 25 percent clay and less than 15 percent coarser than very fine sand.
COMPETING SERIES: These are competing Argo (T), series and the similar Brycan, Datino, Osote, and Panguitch series. Arco soils have common mottles at depths of 20 to 40 inches. Brycan soils have cambic horizons and have more than 15 percent coarser than very fine sand in the particle size control section. Datino, Oscote, and Panguitch soils have mollic epipedons less than 16 inches thick. Also, Datino soils have more than 35 percent rock fragments in the particle size setion. Oscote and Datino soils have cambic horizons. Panguitch soils have less than 18 percent clay in the particle size control section.
GEOGRAPHIC SETTING: Mitch soils formed in mixed volcanic alluvium at elevations of 6,900 to 8,300 feet. They are on valley floors. slope gradients are 0 to 18 percent. The average annual precipitation is 10 to 18 inches and the freeze-free period ranges from 70 to 95 days. The mean annual temperature is 42 to 45 degrees F. and the average summer temperature is 59 to 62 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Guben and Showalter soils and the competing Panguitch soils. Guben soils have a mollic epipedon less than 16 inches thick, have more than 35 percent rock fragments and have a calcic horizon. Showalter soils have an argillic horizon with more than 35 percent rock fragments.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Used for rangeland and wildlife. Vegetation is big sagebrush, rubber rabbitbrush, western wheatgrass, blue grama grass, and reseeded crested wheatgrass.
DISTRIBUTION AND EXTENT: These soils are in the south-central part of Utah. They are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Paunsaugunt Survey Area, Utah, 1969.
REMARKS: These soils were formerly classified as Alluvial soils.