LOCATION SIEBERELL MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal over sandy or sandy-skeletal, mixed, superactive, frigid Aridic Argiustolls
TYPICAL PEDON: Sieberell very gravelly loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 6 inches; grayish brown (10YR 5/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; weak medium and fine subangular blocky structure; soft, very friable, moderately sticky and slightly plastic; many very fine and few fine roots; many very fine and fine and few medium pores; 10 percent cobbles and 30 percent pebbles; neutral (pH 6.6); clear smooth boundary. (5 to 8 inches thick)
Bt--6 to 11 inches; light olive brown (2.5Y 5/4) very gravelly clay loam, olive brown (2.5Y 4/4) moist; moderate medium prismatic structure parting to moderate medium and fine subangular blocky; slightly hard, friable, moderately sticky and moderately plastic; many very fine and few fine roots; many very fine and few fine tubular and interstitial pores; many distinct olive brown (2.5Y 4/4) clay films on faces of peds; 10 percent cobbles, 30 percent pebbles; neutral (pH 6.8); clear wavy boundary. (5 to 9 inches thick)
Bk--11 to 30 inches; pale yellow (2.5Y 7/4) extremely cobbly sandy clay loam, light yellowish brown (2.5Y 6/4) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine and few fine tubular and interstitial pores; 30 percent cobbles, 45 percent pebbles; disseminated lime, common faint lime coatings on tops and sides of fragments, common distinct lime casts on undersides of fragments; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (10 to 20 inches thick)
2C--30 to 60 inches; light yellowish brown (2.5Y 6/4) extremely cobbly loamy sand, light olive brown (2.5Y 5/4) moist; single grain; loose, nonsticky and nonplastic; few very fine roots; 10 percent stones, 30 percent cobbles, 35 percent pebbles; common prominent lime casts on undersides of fragments; strongly effervescent; moderately alkaline (pH 8.0);
TYPE LOCATION: Jefferson County, Montana; 1,600 feet south and 100 feet east of the NW corner of sec. 9, T. 4 N., R. 3 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 40 to 46 degrees F.
Moisture control section - between 4 and 12 inches, dry in some part for six-tenths or more of the cumulative days per year when the soil temperature at a depth of 20 inches is 41 degrees F or higher.
Depth to the argillic horizon - 5 to 8 inches.
Depth to the Bk horizon - 10 to 15 inches.
Depth to 2C horizon - 20 to 40 inches.
Surface stones or boulders - 0 to 3 percent
A noncalcareous transition horizon between the Bk and 2C horizon is allowed.
A horizon - Hue: 10YR or 2.5Y
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Clay content: 18 to 27 percent
Rock fragments: 15 to 50 percent--5 to 20 percent cobbles and stones; 10 to 30 percent pebbles
Reaction: pH 6.6 to 7.3
Bt horizon - Hue: 10YR or 2.5Y
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 3 or 4
Texture: sandy clay loam, loam, or clay loam
Clay content: 25 to 35 percent
Rock fragments: 35 to 60 percent--10 to 20 percent cobbles; 25 to 40 percent pebbles
Reaction: pH 6.6 to 7.8
Bk horizon - Hue: 10YR or 2.5Y
Value: 6, 7, or 8 dry; 5, 6, or 7 moist
Chroma: 2, 3, or 4
Texture: sandy clay loam or loam
Clay content: 12 to 25 percent
Rock fragments: 45 to 75 percent--20 to 30 percent cobbles; 25 to 45 percent pebbles
Calcium carbonate equivalent: 3 to 15 percent
Reaction: pH 7.9 to 8.4
2C horizon - Hue: 10YR or 2.5Y
Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 2, 3 or 4
Texture: coarse sand, loamy coarse sand, or loamy sand
Clay content: 0 to 10 percent
Rock fragments: 50 to 80 percent--0 to 10 percent stones; 20 to 30 percent cobbles; 30 to 40 percent pebbles
Calcium carbonate equivalent: 0 to 5 percent
Reaction: pH 7.4 to 8.4
COMPETING SERIES:
Beaverell (MT) - has a lithologic discontinuity at 10 to 20 inches.
GEOGRAPHIC SETTING:
Landform - stream terraces, alluvial fans and sideslopes of hills.
Elevation - 3,800 to 6,300 feet.
Slope - 0 to 15 percent.
Parent material - alluvium derived from mixed rock sources.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 14 inches.
Mean annual air temperature - 38 to 44 degrees F.
Frost-free period - 70 to 115 days.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability in the argillic horizon and rapid permeability in the sandy-skeletal horizon.
USE AND VEGETATION: Sieberell soils are primarily used for rangeland. The potential native vegetation is mainly bluebunch wheatgrass, prairie junegrass, blue grama, Western wheatgrass, milkvetch, fringed sagewort, hairy goldenaster, phlox, big sagebrush, rubber rabbitbrush, and broom snakeweed
DISTRIBUTION AND EXTENT: Sieberell soils are of small extent in southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jefferson County, Montana, 1998.
REMARKS: Soil interpretation record: MT3009. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the surface to 7 inches, mixed (A, Bt horizons); an argillic horizon from 6 to 11 inches (Bt horizon); a horizon of secondary calcium carbonate accumulation from 11 to 30 inches (Bk horizon); a lithologic discontinuity from 30 to 60 inches (2C horizon); a particle-size control section from 6 to 40 inches (Bt, Bk, 2C horizons). Sieberell soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.