LOCATION SACTUS IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, calcareous, frigid Lithic Torriorthents
TYPICAL PEDON: Sactus very gravelly loam--on a 12 percent smooth, west-facing slope in rangeland at 5,500 feet elevation. (Colors are for dry soil unless otherwise noted. When described on July 25, 1984 the soil was dry from 0 to 2 inches and moist below this depth.)
A1--0 to 2 inches; pale brown (10YR 6/3) very gravelly loam, brown (10YR 4/3) moist; weak thin platy structure parting to weak fine granular; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium and coarse roots; many very fine and fine interstitial pores; 35 percent pebbles, 2 percent cobbles; slightly effervescent; moderately alkaline (pH 7.9); clear smooth boundary. (1 to 8 inches thick)
A2--2 to 5 inches; yellowish brown (10YR 5/4) extremely gravelly loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium and coarse roots; many very fine and fine interstitial pores; 60 percent fine pebbles, 5 percent cobbles; slightly effervescent; moderately alkaline (pH 8.2); gradual smooth boundary. (0 to 4 inches thick)
AC--5 to 9 inches; yellowish brown (10YR 5/4) extremely gravelly loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots; many very fine and fine interstitial pores; 70 percent pebbles, 15 percent cobbles; slightly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (0 to 5 inches thick)
R--9 inches; rhyolite.
TYPE LOCATION: Custer County, Idaho; about 6 miles east of Challis, Idaho; in
Leaton Gulch, about 2,500 feet east and about 3,000 feet south of the northwest corner of section 32, T. 14 N., R. 20 E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 39 to 43 degrees F.
Control section; percent clay - 12 to 20
Rock fragments - average 55 to 85 percent
Depth to lithic contact - 6 to 10 inches
A horizon
Value - 4 through 6 dry
AC horizon
Value - 4 through 6 dry
Chroma - 3 or 4 dry or moist
Texture - FLX-L, GRX-L
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Sactus soils are on ridges and summits. They formed of residuum from extrusive igneous rocks. Slopes are 10 to 40 percent and elevation is 5,000 to 6,200 feet. The climate is cold and moist in winter and dry in summer. Average annual precipitation is 6 to 8 inches; average annual temperature is 38 to 41 degrees F. The frost free period is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dawtonia, Farvant, Holinrock, and Mitring soils. Dawtonia soils are on mountains and ridges and are very deep. Farvant, Holinrock, and Mitring soils are on ridges and foothills. Farvant soils are shallow to paralithic contacts. Holinrock soils are moderately deep to hard bedrock. Mitring soils are moderately deep to a paralithic contact.
DRAINAGE AND PERMEABILITY: Well drained. Slow and medium runoff; moderate permeability.
USE AND VEGETATION: Rangeland. Vegetation is shadscale, Indian ricegrass, Salmon wildrye, and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: East-central Idaho. This soil is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Custer County, Idaho, 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Lithic contact - The boundary at 9 inches (R horizon).
Particle-size control section - The zone from the surface to 9 inches (A1, A2, and AC horizons).