LOCATION HOYMOUNT UTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, siliceous, superactive, frigid Aridic Haplustalfs
TYPICAL PEDON: Hoymount extremely bouldery loam, on a southwest facing 38 percent slope under pinyon pine and Utah juniper at an elevation of 7,520 feet. (Colors are for air-dry soil unless otherwise stated.)
The surface is covered by a duff layer of leaves, needles, and twigs ranging from 0 to 2 inches thick and 10 percent boulders, 30 percent stones, 15 percent cobbles, and 10 percent gravel.
A1--0 to 3 inches; dark reddish brown (5YR 3/3) extremely bouldery loam, dark reddish brown (5YR 3/2) moist; moderate very fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine, few coarse and medium roots; many fine and very fine, common medium, few coarse tubular pores; 10 percent boulders, 30 percent stones, and 10 percent cobbles; moderately alkaline (pH 8.2); clear smooth boundary.
A2--3 to 7 inches; dark reddish brown (5YR 3/3) very stony loam, dark reddish brown (5YR 3/2) moist; moderate medium subangular blocky structure parting to moderate fine and very fine granular; slightly hard, friable, slightly sticky and slightly plastic; many fine and very fine, common coarse and medium roots; many fine and very fine, common medium, and few coarse tubular pores; 5 percent boulders, 20 percent stones, 15 percent cobbles, and 10 percent gravel; moderately alkaline (pH 8.0); abrupt smooth boundary. (combined thickness of the A horizons is 5 to 7 inches)
Bt1--7 to 25 inches; reddish brown (2.5YR 4/4) very stony sandy clay loam, dark reddish brown (2.5YR 3/4) moist; moderate medium subangular blocky structure parting to moderate medium and fine subangular blocky; hard, firm, moderately sticky and moderately plastic; many very fine, common coarse, medium, and fine roots; many fine and very fine, common medium, and few coarse tubular pores; common discontinuous distinct clay films on faces of peds and in pores; 10 percent stones, 20 percent cobbles, and 10 percent gravel; moderately alkaline (pH 7.9); gradual smooth boundary.
Bt2--25 to 43 inches; reddish brown (2.5YR 5/4) very stony clay loam, reddish brown (2.5YR 4/4) moist; moderate medium subangular blocky structure parting to moderate fine and very fine subangular blocky; hard, firm, moderately sticky and moderately plastic; common medium, fine, and very fine, few coarse roots; common fine and very fine tubular pores; common continuous distinct clay films on faces of peds and in pores; 25 percent stones, 20 percent cobbles, and 10 percent gravel; slightly alkaline (pH 7.8); gradual wavy boundary.
Bt3--43 to 56 inches; red (10R 4/6) very stony clay loam, red (10R 4/6) moist; moderate coarse subangular blocky structure parting to moderate fine and very fine subangular blocky; very hard, very firm, moderately sticky and moderately plastic; few medium, fine, and very fine roots; common fine and very fine tubular pores; common continuous distinct clay films on faces of peds and in pores; 25 percent stones, 20 percent cobbles, and 10 percent gravel; slightly alkaline (pH 7.8). (combined thickness of the Bt horizons is 35 to 53 inches)
R--56 inches; unweathered sandstone bedrock.
TYPE LOCATION: Uintah County, Utah; about 2 miles southwest of Hoy Mountain on the USGS Hoy Mountain Quadrangle; about 800 feet east, 1,300 feet south of the northwest corner of sec. 27, T.1S., R.25E., SLBM; 40 degrees, 42 minutes, 34 seconds north latitude and 109 degrees, 06 minutes, 04 seconds west longitude. NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture: The moisture control section is affected by precipitation that falls evenly through the year with a slight increase in late summer and fall. This soil has an aridic ustic moisture regime.
Mean annual soil temperature ranges from 44 to 47 degrees F.
Depth to lithic contact: 40 to 60 inches to sandstone
Particle-size control section: 27 to 35 percent clay, and 50 to 70 percent rock fragments (predominantly subangular stones and cobbles from quartzite and sandstone lithology).
A horizon:
Hue: 5YR or 7.5YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 3 or 4 dry, 2 or 3 moist
Reaction: neutral to moderately alkaline
Bt horizon:
Hue: 10R to 5YR
Texture: sandy clay loam or clay loam modified by 50 to 70 percent rock fragments (predominantly stones and cobbles)
Reaction: neutral to moderately alkaline
COMPETING SERIES: There are no competing series in this family.
GEOGRAPHIC SETTING:
Parent material: slope alluvium and colluvium derived from quartzite and sandstone
Landform: mountain slopes
Slopes: 25 to 50 percent
Elevation: 7,000 to 8,000 feet
Mean annual precipitation: 12 to 16 inches
Mean annual air temperature: 42 to 45 degrees F.
Frost-free period: 90 to 110 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bigtom, Dokie, Namlot, Cortyzack, and Boxring soils.
Bigtom soils have mollic epipedons greater than 16 inches thick and are on north facing slopes.
Dokie soils are very deep and have cryic temperature regimes.
Namlot and
Boxring soils are shallow to bedrock.
Cortyzack soils are very deep and are on hillslopes.
DRAINAGE AND PERMEABILITY: Well drained; high runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used principally for rangeland, wildlife habitat, and recreation. Potential vegetation consists of pinyon pine, Utah juniper, bluebunch wheatgrass, black sagebrush, Indian ricegrass, and birchleaf mountainmahogany. These soils have been correlated to Upland Stony Loam (Pinyon pine - Utah juniper) - 047CY335UT, in Utah.
DISTRIBUTION AND EXTENT: Northeastern Utah; LRR E, MLRA 47. The series is of moderate extent. This name is coined from a geographic name in the area.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Uintah County, Uintah Area Soil Survey, Utah, 1998.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 7 to 27 inches. (Bt1 and Bt2 horizons)
Ochric epipedon: The zone from the surface to 7 inches (A1 and A2 horizons)
Argillic horizon: The zone from 3 to 56 inches. (Bt1, Bt2, and Bt3 horizons)
Lithic contact: The contact with sandstone at 56 inches. (R layer)
The surface texture modifier was determined following the guidelines outlined in the Utah document, "Procedures for Distributing Rock Fragments on the Surface Layer into the Upper 6 inches of Soil and Subsequent Naming of Map Units, April 1979."
The cation exchange activity class was inferred from laboratory data from similar soils in the Uintah Area Soil Survey.
Taxonomic version: Eighth Edition, 1998.