LOCATION GREYCLIFF MTEstablished Series
TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, frigid Aridic Natrustolls
TYPICAL PEDON: Greycliff silt loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 5 inches; grayish brown (10YR 5/2) silt loam, very dark gray (10YR 3/1) moist; weak medium prismatic structure parting to moderate fine granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine and common medium roots; many very fine, common fine and few medium pores; strongly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (3 to 8 inches thick)
Bt--5 to 11 inches; gray (10YR 5/1) clay loam, very dark grayish brown (10YR 3/2) crushed, moist; weak medium prismatic structure parting to strong medium subangular blocky; hard, friable, moderately sticky and moderately plastic; many very fine and fine and few medium roots; many very fine and common fine pores; common faint clay films on faces of peds and lining pores; strongly effervescent; strongly alkaline (pH 8.6); gradual wavy boundary. (4 to 10 inches thick)
Btkn--11 to 15 inches; light brownish gray (10YR 6/2) clay loam; dark gray (10YR 4/1) moist; moderate medium prismatic structure parting to strong medium subangular blocky; hard, friable, moderately sticky and moderately plastic; common very fine and fine and few medium roots; many very fine and common fine pores; common faint clay films on faces of peds and lining pores; common fine masses of lime; violently effervescent; strongly alkaline (pH 9.0); clear smooth boundary. (0 to 10 inches thick)
Bkn--15 to 31 inches; light brownish gray (10YR 6/2) clay loam, dark gray (10YR 4/1) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine roots; common very fine and few fine and medium pores; common fine masses of lime; violently effervescent; very strongly alkaline (pH 9.2); clear smooth boundary. (5 to 18 inches thick)
C1--31 to 37 inches; light brownish gray (10YR 6/2) sandy loam, dark gray (10YR 4/1) moist; common fine distinct dark yellowish brown (7.5YR 5/3) moist redox concentrations; massive; hard, friable, slighty sticky and slightly plastic; few very fine roots; common very fine and few fine and medium pores; slightly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (0 to 14 inches thick)
2C2--37 to 60 inches; variegated colors, very cobbly loamy sand; single grain; loose, nonsticky and nonplastic; few very fine roots; 20 percent cobbles and 25 percent pebbles; slightly alkaline (pH 7.6).
TYPE LOCATION: Gallatin County, Montana; 500 feet north and 200 feet east of the S.W. corner of section 21, T.2N., R.2E.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 43 to 47 degrees F.
Moisture control section - between 4 and 12 inches, dry in some part for six tenths or more of the cumulative days when the soil temperature at 20 inches is higher than 41 degrees F.
Mollic epipedon thickness - 7 to 12 inches.
Depth to 2C horizon - 20 to 40 inches.
Depth to seasonal high water table - 24 to 42 inches.
A horizon - Chroma: 1 or 2
Texture: silt loam or loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 5 percent pebbles
Electrical conductivity: 0 to 4 mmhos/cm
Calcium carbonate equivalent: 2 to 10 percent
Reaction: pH 7.4 to 8.4
Bt horizon - Value: 5 or 6 dry; 3 or 4 moist
Chroma: 1 or 2
Texture: loam or clay loam
Clay content: 25 to 35 percent
Rock Fragments: 0 to 5 percent pebbles
Calcium carbonate equivalent: 2 to 10 percent
Electrical conductivity: 2 to 8 mmhos/cm
Reaction: pH 8.5 to 9.6
Note: Some pedons have Btn horizons with SAR greater than 13.
Btkn horizon - Value: 4 or 5 moist
Chroma: 1, 2 or 3
Clay content: 27 to 35 percent
Rock fragments: 0 to 5 percent pebbles
Calcium carbonate equivalent: 10 to 30 percent
Electrical conductivity: 2 to 8 mmhos/cm
Sodium adsorption ratio: 13 to 30
Reaction: pH 9.0 to 9.6
Bkn horizon - Value: 6 or 7 dry; 4 or 5 moist
Chroma: 1 to 3
Texture: sandy loam, sandy clay loam, loam or clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 5 percent pebbles
Calcium carbonate equivalent: 15 to 30
Electrical conductivity: 2 to 8 mmhos/cm
Sodium adsorption ratio: 13 to 30
Reaction: pH 8.5 to 9.6
C1 horizon - Value: 6 or 7 dry; 4 or 5 moist
Chroma: 1, 2 or 3
Texture: sandy loam, sandy clay loam, or clay loam
Clay content: 18 to 30 percent
Rock fragments: 0 to 10 percent pebbles
Electrical conductivity: 0 to 4 mmhos/cm
Reaction: pH 7.4 to 8.4
2C2 horizon - Value: 6, 7 or variegated dry; 4 or 5 moist
Chroma: 2 or 3
Texture: loamy sand, sand, loamy coarse sand or coarse sand
Clay content: 0 to 10 percent
Rock fragments: 0 to 50 percent--0 to 25 percent pebbles, 0 to 25 percent cobbles
Reaction: pH 7.4 to 8.4
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - low stream terraces and floodplains protected from flooding.
Elevation - 4,000 to 4,400 feet.
Slope - 0 to 2 percent.
Parent material - calcareous alluvium.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 14 inches.
Mean annual air temperature - 41 to 45 degrees F.
Frost-free period - 95 to 120 days.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; moderately slow permeability.
USE AND VEGETATION: Greycliff soils are used mainly for rangeland and wildlife habitat. Potential native vegetation is mainly alkali sacaton, inland saltgrass, western wheatgrass, sedges and rushes.
DISTRIBUTION AND EXTENT: Greycliff soils are of small extent in southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Gallatin County, Montana; 1997.
REMARKS: Soil interpretation record: MT1455. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 11 inches (A, Bt horizons); a natric horizon from 11 to 15 inches (Btkn horizon); a calcic horizon from 15 to 31 inches (Bkn horizon); a particle size control section from 5 to 40 inches (Bt, Btkn, Bkn, C, 2C horizons). Greycliff soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.