LOCATION HIIBNER UTEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Typic Argixerolls
TYPICAL PEDON: Hiibner gravelly clay loam--native grasses and shrubs. (Colors are for air-dry soil unless otherwise stated.)
A1--0 to 3 inches; very dark grayish brown (10YR 3/2) gravelly
clay loam, very dark brown (10YR 2/2) moist; weak thin platy structure parting to weak fine granular; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; medium fine pores; 20 percent gravel, 5 percent cobbles and 5 percent stones; neutral (pH 6.6); clear wavy boundary. (3 to 6 inches thick)
A2--3 to 6 inches; dark grayish brown (10YR 4/2) gravelly clay
loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common fine and few medium roots; many fine and many large pores; 20 percent gravel, 5 percent cobbles and 5 percent stones; neutral (pH 6.6); clear wavy boundary. (3 to 6 inches thick)
Bt1--6 to 12 inches; brown (7.5YR 4/2) very cobbly clay, dark
brown (7.5YR 3/2) moist; strong medium prismatic structure parting to moderate fine angular blocky structure; extremely hard, extremely firm, sticky and plastic; common medium roots; common fine and medium pores; common moderately thick clay films; 20 percent gravel, 20 percent cobbles and 10 percent stones; slightly acid (pH 6.2); gradual wavy boundary. (6 to 12 inches thick)
Bt2--12 to 27 inches; reddish brown (5YR 5/4) extremely cobbly
clay, reddish brown (5YR 4/4) moist; strong coarse prismatic structure parting to moderate fine angular blocky structure; extremely hard, extremely firm, very sticky, and very plastic; common fine and medium roots; common fine pores; common thick clay films; 20 percent gravel, 30 percent cobbles and 10 percent stones; slightly acid (pH 6.1); gradual wavy boundary. (12 to 15 inches thick)
Bt3--27 to 60 inches; reddish brown (5YR 5/4) extremely cobbly
clay, reddish brown (5YR 4/4) moist; strong coarse prismatic structure parting to moderate fine angular blocky structure; extremely hard, extremely firm, very sticky, very plastic; few fine and medium roots; few fine and medium pores; common thick clay films; 30 percent gravel, 40 percent cobbles and 10 percent stones; slightly acid (pH 6.2).
TYPE LOCATION: Cache County, Utah; about 1 mile west of Mendon; 30 feet west and 20 feet north of the northeast corner, sec. 1, T. 11 N., R. 2 W.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 11 to 20 inches thick. The combined thickness of the A and Bt horizons ranges from 45 to 60 inches or more. The soil is slightly calcareous below depths of 45 inches in some pedons. Rock fragments are mainly gravel and cobble size angular sandstone and quartzite rock fragments, but include 5 to 15 percent stones. The mean annual soil temperature ranges from 48 to 52 degrees F, and the mean summer soil temperature at a depth of about 20 inches ranges from 65 to 68 degrees F. The soils are moist 55 to 65 percent of the time, but are dry for 60 to 75 consecutive days in the 8 to 24 inch particle size control section in the summer and autumn.
The A horizon has hue of 10YR or 7.5YR, value of 3 or 4 dry, 2 or 3 moist, and chroma of 2 or 3. It contains 3 to 6.5 percent organic matter. This horizon has weak thin platy to fine granular or fine subangular blocky structure. It is neutral or slightly acid and is 6 to 12 inches thick.
The Bt horizon has hue of 10YR or 5YR, value of 4 or 5 dry, 3 or 4 moist, and chroma of 2 to 6. It has moist chroma of 3 only in the upper 4 to 8 inches. This horizon is extremely cobbly clay or extremely stony cobbly clay loam with more than 35 percent clay and 15 to 30 percent gravel, 20 to 40 percent cobbles and about 10 percent stones. It has moderate to strong, medium to coarse prismatic structure.
The Bt horizon has common to continuous moderately thick or thick clay films. It is slightly acid to mildly alkaline and is 36 to 50 inches or more thick.
COMPETING SERIES: These are the Fiddler (T), Immig (T), and the Provig (T) series. The Fiddler and Immig soils have bedrock from 20 to 40 inches. The Provig soil has a mean annual soil temperature of 54 to 56 degrees F.
GEOGRAPHIC SETTING: Hiibner soils are at elevations of 4,500 to 6,000 feet above sea level on gently sloping fan terraces and steep dissected mountain foot slopes. Slopes range from 1 to 30 percent. These soils formed in colluvium and alluvium from sandstone and quartzite. The climate is moist subhumid. Mean annual temperature is 45 to 48 degrees F, mean summer temperature is 60 to 67 degrees F. The average annual precipitation ranges from 16 to 20 inches and the freeze-free period is 100 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Crowshaw, Henricks, McMurdie, Nebeker and Parleys soils. Crowshaw soils have gravelly cobbly loam control sections with less than 35 percent cobbles and gravel. Henricks, McMurdie, Nebeker, and Parleys soils are not cobbly or stony.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: These soils are used primarily as rangeland with small areas of dry cropland. The native vegetation is big sagebrush, bluebunch wheatgrass, western wheatgrass, cheatgrass, annual sunflower, mulsear dock and yarrow.
DISTRIBUTION AND EXTENT: Northern Utah. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Cache County, Utah, 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon -the zone from the surface of the soil to 12
inches. (A1, A2, Bt1 horizons)
Argillic horizon -the zone from 6 to 60 inches. (Bt1, Bt2, Bt3 horizons)