LOCATION MILL HOLLOW UTEstablished Series
TAXONOMIC CLASS: Fine-loamy, carbonatic, mesic Aridic Calcixerolls
TYPICAL PEDON: Mill Hollow very cobbly loam - rangeland. (Colors are for air-dry soil unless otherwise stated.)
A1--0 to 2 inches; brown (10YR 5/3) very cobbly loam, dark brown (10YR 3/3) moist; weak thin platy structure that parts to weak fine granules; soft, friable, slightly sticky, plastic; common fine, medium and few large roots; vesicular pores; noncalcareous; moderately alkaline (pH 8.2); clear smooth boundary. (2 to 4 inches thick)
A2--2 to 7 inches; brown (10YR 5/3) loam, brown (10YR 4/3) moist; weak fine granular structure; soft, friable, slightly sticky, plastic; common fine, medium and few large roots; few fine and medium tubular pores; slightly calcareous; moderately alkaline (pH 8.2); clear smooth boundary. (5 to 6 inches thick)
Ck1--7 to 10 inches; brown (10YR 5/3) loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, plastic; common fine and few medium roots; few medium and large tubular pores; strongly calcareous; segregated lime as veining and splotches; strongly alkaline (pH 8.5); gradual smooth boundary.
Ck2--10 to 14 inches; pale brown (10YR 6/3) heavy loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic; few fine and medium roots; few fine and medium tubular pores; strongly calcareous; segregated lime as veining and splotches; strongly alkaline (pH 8.6); gradual smooth boundary. (5 to 6 inches thick)
Ck3--14 to 34 inches; very pale brown (10YR 8/2) loam, very pale brown (10YR 7/3) moist; massive, discontinuously weakly cemented, friable, slightly sticky, slightly plastic; few fine roots few fine tubular pores; very strongly calcareous; high concentration of lime; strongly alkaline (pH 8.8).
Ck4--34 to 37 inches; same as above horizon except extremely stony loam.
TYPE LOCATION: Beaver County, Utah; 4 miles north and 6 miles east of Antelope Point SE1/4 of sec. 26, T.24S., R.8W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 degrees to 50 degrees F., the mean summer soil temperature at a depth of 20 inches is 63 degrees to 65 degrees F. These soils are dry in the moisture control section more than 50 percent of the time the soil temperature is above 41 degrees F. and are continually dry for 50 to 70 consecutive days during the summer months is more than 6 out of 10 years.
Depth to the Ck horizons is 7 to 10 inches. The surface ranges in rock fragments from few to more than 50 percent, mainly cobbles.
The A horizon has hue of 7.5YR or 10YR and chroma of 2 or 3. It has weak thin platy to weak fine granular structure. This horizon is slightly calcareous to noncalcareous.
The Ck horizon to a depth of about 34 inches is brown, pale brown or white. Value is 5 through 8 dry, 4 through 7 moist, and chroma is 2 or 3. Stony or extremely stony loam may occur below about 34 inches.
COMPETING SERIES: These are the Blackett and Calita series. Blackett soils have less than 18 percent clay in the control section. Calita soils are deeper than 18 inches to the calcic horizon and have less than 40 percent lime in the calcic horizon.
GEOGRAPHIC SETTING: Mill Hollow soils are on gently sloping to steep alluvial fans, mountain slopes and rolling hills at elevations of 5,900 to 6,500 feet. Slopes are 1 to 30 percent. The mean annual precipitation ranges from 13 inches. Mean annual air temperature is about 65 degrees F. Freeze-free period is about 100 to 108 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ushar and Pharo soils. Ushar soils have B2 horizons. Pharo soil have more than 35 percent gravel in the control section.
DRAINAGE AND PERMEABILITY: Well-drained; medium or rapid runoff; moderate permeability.
USE AND VEGETATION: These soils are used principally for wildlife and spring and winter grazing by sheep. Potential vegetation consists of pinyon-juniper, big sagebrush, Indian ricegrass, bluebunch wheatgrass, and spiked wheatgrass.
DISTRIBUTION AND EXTENT: Mountain areas of southwestern Utah. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Beaver County, Utah, 1972.