LOCATION SKUTUM UT+IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic Pachic Argicryolls
TYPICAL PEDON: Skutum fine sandy loam--woodland. (Colors are for air-dry soil unless otherwise stated.) A 1-inch layer of aspen litter, duff, and twigs is on the surface.
A1--0 to 6 inches; brown (7.5YR 4/2) fine sandy loam; dark brown (7.5YR 3/2) moist; weak very fine granular structure; soft, friable, nonsticky and nonplastic; common fine and very fine roots; common very fine pores; 10 percent gravel; neutral (pH 7.0); clear smooth boundary. (5 to 7 inches thick)
A2--6 to 12 inches; brown (7.5YR 5/2) fine sandy loam, dark brown (7.5YR 3/2) moist; weak medium subangular blocky structure parting to weak very fine granular; soft, friable, nonsticky and nonplastic; common very fine, fine and medium roots; common very fine interstitial pores; 10 percent gravel; neutral (pH 7.0); clear smooth boundary. (5 to 8 inches thick)
A3--12 to 17 inches; brown (7.5YR 5/2) loam; dark brown (7.5YR 3/2) moist; weak medium subangular blocky structure parting to weak fine granular; slightly hard, friable; slightly sticky and nonplastic; common medium, coarse and few very fine roots; common very fine interstitial pores; 15 percent gravel; slightly acid (pH 6.5); clear smooth boundary. (4 to 6 inches thick)
Bt1--17 to 24 inches; brown (7.5YR 5/4) gravelly clay loam, brown (7.5YR 4/4) moist; moderate fine and medium subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; common medium, coarse and few very fine roots; common very fine tubular pores; common moderately thick clay films on faces of peds; 20 percent gravel; slightly acid (pH 6.5) gradual wavy boundary. (6 to 9 inches thick)
Bt2--24 to 36 inches; mixed about 50 percent each of brown (7.5YR 5/4) and very dark gray (N 3/) gravelly clay; brown (7.5YR 4/4) and black (N 2/) moist; moderate fine and medium subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; few very fine roots; common very fine tubular pores; common moderately thick clay films on faces of peds; 15 percent gravel; slightly acid (pH 6.5); clear wavy boundary. (10 to 14 inches thick)
2C--36 to 50 inches; brownish yellow (10YR 6/6) gravelly sandy loam, yellowish brown (10YR 5/6) moist; massive; slightly hard, firm, slightly sticky and nonplastic; 25 percent gravel and 5 percent cobbles; slightly acid (pH 6.5); abrupt wavy boundary (10 to 24 inches).
Cr--50 inches; fractured gray shale.
TYPE LOCATION: Kane County, Utah; junction of Robinson Canyon and East Fork Sevier River; SE 1/4 of sec. 10, T. 39 S., R. 4 1/2 W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 36 to 44 degrees F., and the mean summer soil temperature at depth of 20 inches ranges from 54 to 58 degrees F.
The mollic epipedon ranges from 16 to 30 inches thick. Depth to paralithic contact is 40 to 60 inches. Rock fragments average 15 to 35 percent in the particle size control section and are less than 10 inches in diameter.
The A horizon has hue of 5YR to 10YR, value of 3 to 5 dry, 2 or 3 moist and chroma of 2 to 4 dry and 2 or 3 moist. It is moderately acid to neutral.
The Bt horizon has hue of 5YR to 10YR, value of 4 to 7 dry, 3 to 6 moist and chroma of 3 to 6 (few to many gleyed black N 2/ moist mottles may be present.) It ranges from gravelly sandy clay loam, gravelly clay loam to cobbly clay or gravelly clay and has about 35 to 45 percent clay and 15 to 35 percent rock fragments. Reaction is neutral to moderately acid.
The 2C horizon has hue of 2.5YR to 10YR, value of 3 to 6 moist, 4 to 6 dry, and chroma of 3 to 6. It is gravelly sandy loam to gravelly sandy clay. Reaction is neutral to moderately acid.
COMPETING SERIES:
Bischoff (T ID) and
Guero (T CO) soils are greater than 60 inches to bedrock.
Burnette (MT), Fulcher (CO), and Paulson (WY) soils have Bk horizons.
Cochetopa (CO) soils have rock fragments larger than 10 inches in diameter and do not have sandy loam 2C horizons.
Friana (AZ) soils have less than 15 percent rock fragments in the argillic horizon and formed in volcanic cinders, ash and basalt.
Faim (UT), Grouseville (T ID), Perinos (T ID), Slights (T ID), and Sudpeak (ID) soils have less than 15 percent rock fragments in the particle size control section.
Leemorris (OR), Mancos (T CO) and Runlett (T CO) soils have bedrock at 20 to 40 inches.
Luna (AZ) soils have decomposing ash or tuff at depths of 20 to 40 inches.
Mayflower (CO) soils have a paralithic contact at depths of 20 to 40 inches.
Perinos (T UT) soils have less than 5 percent rock fragments in the particle size control section.
Richens (UT) soils has a solum deeper than 50 inches.
Teedown (T CO) soils have stony C horizons and contain 5 to 20 percent rock fragments in the B horizons.
Toponce (ID) soils lack gravelly 2C horizons and are very deep.
GEOGRAPHIC SETTING: The Skutum soils are on structural benches, toeslopes, mountain slopes, and mesas at elevations of 6,400 to 10,100 feet. They formed in gravelly alluvium and colluvium from limestone, conglomerate, sandstone and shale. Slope gradients are 1 to 60 percent. The average annual precipitation is 18 to 35 inches, the freeze-free period ranges from 20 to 80 days. The mean annual temperature is 35 to 44 degrees F., and the average summer temperature is 54 to 58 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Losee, Osote, Sessions, Sevier, and Uinta soils. Losee soils lack both a mollic epipedon and an argillic horizon and have more than 35 percent rock fragments in the control section. Osote soils have an ochric epipedon and have over 40 percent carbonates. Sevier soils lack argillic horizons and have a paralithic contact of less than 20 inches thick. Sessions soils have a mollic epipedon less than 20 inches thick. Uinta soils lack a mollic epipedon and have 18 to 27 percent clay in the particle size control section.
DRAINAGE AND PERMEABILITY: Well and moderately well drained; medium runoff; slow permeability.
USE AND VEGETATION: Used for rangeland, wildlife and timber. The native vegetation is aspen, prostrate juniper, needleandthread grass, slender wheatgrass, Kentucky bluegrass, mountain brome, squirreltail, mutton bluegrass and scattered white fir.
DISTRIBUTION AND EXTENT: These soils are from the north to south-central part of Utah and western Colorado. They are not extensive. MLRA 47 and 48A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Kane County (Paunsaugunt Area), Utah, 1969.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon (Pachic feature) - from the surface of the soil to 17 inches (A1, A2, A3 horizons)
Argillic horizon - the zone from 17 to 36 inches (Bt1, Bt2 horizons)
Classification: Keys to Soil Taxonomy, Eighth Edition, 1998.