LOCATION CORBLY MTEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, frigid Entic Haplustolls
TYPICAL PEDON: Corbly very gravelly sandy loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 5 inches; brown (10YR 4/3) very gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; loose, slightly sticky and nonplastic; common very fine and fine and few medium roots; 40 percent pebbles and 5 percent cobbles; slightly alkaline (pH 7.4); gradual smooth boundary. (4 to 7 inches thick)
AC--5 to 12 inches; brown (10YR 5/3) very gravelly sandy loam, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; 40 percent pebbles and 10 percent cobbles; slightly alkaline (pH 7.8); gradual smooth boundary. (0 to 8 inches thick)
Ck1--12 to 22 inches; light yellowish brown (10YR 6/4) extremely gravelly loamy sand, dark yellowish brown (10YR 4/4) moist; single grain; loose, nonsticky and nonplastic; few very fine and fine and few medium roots; common distinct lime coatings on underside of coarse fragments; 50 percent pebbles and 15 percent cobbles; strongly effervescent; moderately alkaline (pH 8.2); diffuse smooth boundary. (8 to 20 inches thick)
Ck2--22 to 60 inches; light yellowish brown (10YR 6/4) extremely gravelly sand, dark yellowish brown (10YR 4/4) moist; single grain; loose, nonsticky and nonplastic; few very fine roots; common distinct lime coatings on underside of coarse fragments; 60 percent pebbles and 15 percent cobbles; strongly effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Gallatin County, Montana; 1,600 feet east and 1,800 feet south of the northwest corner of sec. 27, T.1N., R.5E.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 41 to 45 degrees F.
Moisture control section - between 12 and 35 inches; not dry in all parts for 45 consecutive days.
Mollic epipedon thickness - 7 to 12 inches.
Depth to Ck horizon - 7 to 12 inches.
A horizon - Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Texture: sandy loam or loam
Clay content: 15 to 25 percent
Rock fragments: 15 to 55 percent--10 to 40 percent pebbles, 5 to 15 percent cobbles, 0 to 10 percent stones
Reaction: pH 6.6 to 7.8
AC horizon - Chroma: 2 or 3
Texture: coarse sandy loam, sandy loam or loam
Clay content: 10 to 20 percent
Rock fragments: 25 to 60 percent--20 to 40 percent pebbles, 5 to 20 percent cobbles
Reaction: pH 6.6 to 7.8
Note: Some pedons contain Bw horizons that do not extend to a depth of 10 inches.
Ck horizons - Value: 4 or 5 moist
Chroma: 2, 3 or 4
Texture: loamy sand, loamy coarse sand, sand or coarse sand
Clay content: 0 to 10 percent
Rock fragments: 40 to 85 percent-- 25 to 60 percent pebbles,
15 to 25 percent cobbles
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES:
Wabek (ND) - formed in glaciofluvial deposits; does not have Ck horizons.
GEOGRAPHIC SETTING:
Landform - stream terraces, alluvial fans and outwash plains.
Elevation - 4,400 to 5,000 feet.
Slope - 0 to 8 percent.
Parent material - mixed alluvium.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 15 to 19 inches.
Mean annual air temperature - 39 to 43 degrees F.
Frost-free period - 90 to 110 days.
DRAINAGE AND PERMEABILITY: Well drained; moderately rapid permeability.
USE AND VEGETATION: Corbly soils are used mainly for rangeland and wildlife habitat. Potential native vegetation may include bluebunch wheatgrass, Idaho fescue, sedges, needleandthread, lupine, western yarrow, pussytoes, rose, common snowberry and skunkbush sumac as well as other grasses, forbs and woody shrubs.
DISTRIBUTION AND EXTENT: Corbly 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: MT1622. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the surface to 12 inches (A, AC horizons); horizons of secondary carbonate accumulation from 12 to 60 inches (Ck1, Ck2 horizons); a particle-size control section from 10 to 40 inches (Ck1, Ck2 horizons). Corbly soils have a frigid temperature regime and an ustic moisture regime.