LOCATION MULEYPOINT UTEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Petrocalcic Palexerolls
TYPICAL PEDON: Muleypoint very cobbly loam on a 22 percent northwest facing slope--rangeland. (Colors are for air-dry soil unless otherwise stated). The soil surface is covered with 20 percent cobbles and 60 percent gravels.
A--O to 4 inches; brown (10YR 4/3) very cobbly loam, very dark grayish brown (10YR 3/2) moist; weak moderately thick platy structure parting to moderate very fine granular; slightly hard, friable, slightly sticky and plastic; common fine and very fine roots, many very fine vesicular and interstitial pores; 5 percent stones, 5 percent cobbles and 20 percent gravels; mildly alkaline (pH 7.6); clear smooth boundary. (3 to 4 inches thick)
Bt--4 to 11 inches; brown (10YR 4/3) gravelly clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, firm, sticky and plastic; few medium fine and very fine roots; few coarse, medium, fine and very fine pores; common, distinct clay films on faces of peds and rock fragments; 20 percent gravels; mildly alkaline (pH 7.6); clear wavy boundary. (4 to 7 inches thick)
Btk--11 to 14 inches; pale brown (10YR 6/3) gravelly clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, firm, sticky and plastic; few fine and very fine roots; few fine and very fine tubular pores; few, distinct clay films lining pores and on rock fragments; 5 percent cobbles and 25 percent gravels; strongly effervescent, carbonates are disseminated and in few, fine soft masses; distinct (pH 8.4); clear wavy boundary. (O to 3 inches thick)
Bk--14 to 19 inches; pale brown (10YR 6/3) gravelly clay loam, brown (10YR 4/3) moist; massive; hard, firm, slightly sticky and plastic; few fine and very fine roots; few fine and and very fine tubular pores; 20 percent cobbles, 15 percent gravels, and 10 percent gravel-size hardpan fragments; violently effervescent, carbonates are disseminated in common fine flecks and coat rock fragments; strongly alkaline (pH 8.6); abrupt wavy boundary. (5 to 10 inches thick).
Bkm--19 inches; indurated carbonate hardpan.
TYPE LOCATION: Iron County, Utah; about 15.3 miles north northeast of Paragonah; 960 feet north and 260 feet west of the southeast corner of sec. 20, T. 31 S., R. 7 W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 47 to 50 degrees F., and the mean summer soil temperature is 64 to 68 degrees F. The moisture regime is Xeric bordering on Aridic.
Depth to the petrocalcic horizon ranges from 10 to 20 inches. Depth to secondary carbonates ranges from 7 to 14 inches. Mollic epipedon is 7 to 12 inches thick.
The A horizon has value of 4 or 5 dry and chroma of 2 or 3.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 to 4. Texture is gravelly clay loam with 27 to 35 percent clay and 15 to 35 percent rock fragments. Rock fragments are mainly gravel and cobbles.
The Bk horizon has hue of 10YR or 7.5YR, value of 5 to 7 dry, 3 to 5 moist, and chroma of 2 to 4. Texture is cobbly clay loam, very gravelly sandy clay loam, very cobbly loam or extremely gravelly clay loam with 25 to 70 percent rock fragments and hardpan fragments. Coarse fragments are mainly gravels and cobbles. It is moderately alkaline or strongly alkaline.
COMPETING SERIES: This is the Pavant (UT) and Snowville (UT) series. Pavant soils do not have an argillic horizon and have less than 25 percent coarse fragments in the particle size control section. Snowville soils have basalt bedrock at 20 to 30 inches.
GEOGRAPHIC SETTING: Muleypoint soils are on foothills and highly dissected fan terraces at elevations of 5,800 to 6,600 feet. Slopes range from 15 to 40 percent. These soils formed in alluvium and colluvium derived dominantly from basic and intermediate igneous rocks. The mean annual air temperature is 45 to 48 degrees. Average annual precipitation is 12 to 14 inches. The freeze-free period is 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Birdow, Manderfield, Monroe, Ocambee and Robroy series. Birdow and Monroe soils are greater than 60 inches deep and do not have argillic horizons and occur in broad drainageways. Manderfield soils are greater than 60 inches deep and have an abrupt textural change to sandy or sandy-skeletal. They occur on gently sloping fan terraces downslope from the Muleypoint soils. Ocambee and Robroy soils are 20 to 40 inches deep to igneous bedrock and have greater than 35 percent clay in the particle size control section. They occur on steeply sloping mountainsides.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Used for rangeland and wildlife habitat. The native vegetation is Wyoming big sagebrush, bluebunch wheatgrass, Indian ricegrass, needleandthread, blue grama, galleta, Douglas rabbitbrush, and globemallow.
DISTRIBUTION AND EXTENT: Southwestern Utah. These soils are not extensive. MLRA 28A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Iron County (Iron-Washington Area), Utah, 1997. The series is named after Muleypoint, a mountain to the northeast part of the survey area.
REMARKS: The diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - a dark surface horizon with greater than 1 percent organic matter, about 11 inches thick.
Argillic horizon - a zone of clay accumulation from a depth of about 4 to 14 inches.
Petrocalcic horizon - an indurated carbonate hardpan at a depth of 19 inches.
The classification is based on the "Keys to Soil Taxonomy, Eighth Edition, 1998". The cation exchange activity class is an estimate based on NASIS data.