LOCATION ACCOLA MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Calcic Argicryolls
TYPICAL PEDON: Accola loam, forested. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inch; partially decomposed forest litter. (1 to 2 inches thick)
A--1 to 4 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine platy structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots and few medium roots; 5 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (3 to 7 inches thick)
Bt1--4 to 9 inches; brown (10YR 4/3) loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; soft, very friable, moderately sticky and moderately plastic; common very fine and fine roots; common distinct clay films on faces of peds and lining pores; 5 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (4 to 10 inches thick)
Bt2--9 to 18 inches; yellowish brown (10YR 5/4) gravelly clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common distinct clay films on faces of peds and lining pores; 10 percent gravel and 5 percent cobbles; neutral (pH 6.8); clear wavy boundary. (0 to 10 inches thick)
Bk1--18 to 29 inches; light yellowish brown (10YR 6/4) very gravelly clay loam, yellowish brown (10YR 5/4) moist; weak coarse prismatic structure; soft, very friable, moderately sticky and moderately plastic; few fine and medium roots; 30 percent gravel and 15 percent cobbles; common fine seams of lime; violently effervescent; slightly alkaline (pH 7.8); gradual smooth boundary. (5 to 12 inches thick)
Bk2--29 to 60 inches; very pale brown (10YR 7/4) extremely cobbly loam, light yellowish brown (10YR 6/4) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; few fine roots; 35 percent gravel and 30 percent cobbles; disseminated lime; common fine masses of lime; common distinct lime coatings on underside of rock fragments; violently effervescent; slightly alkaline (pH 7.8)
TYPE LOCATION: Gallatin County, Montana; 1100 feet south and 400 feet east of the NW corner of sec. 4, T.5N., R.4E.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 36 to 40 degrees F.
Mean summer soil temperature - 45 to 47 degrees F.
Mollic epipedon thickness - 7 to 13 inches.
Depth to skeletal Bk horizon - 12 to 22 inches.
A horizon - Value: 4 or 5 dry
Chroma: 1 or 2
Clay content: 18 to 27 percent
Rock fragments: 0 to 10 percent gravel
Reaction: pH 5.6 to 7.3
Bt horizons - Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2, 3 or 4
Texture: clay loam, loam
Clay content: 25 to 35 percent
Rock fragments: 0 to 20 percent -- 0 to 5 percent cobbles; 0 to 15 percent gravel
Reaction: 5.6 to 7.8
Bk horizons - Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 2, 3, or 4
Texture: loam, clay loam
Clay content: 18 to 30 percent
Rock fragments: 35 to 70 percent--15 to 30 percent cobbles; 20 to 40 percent gravel
CaCO3 equivalent: 15 to 40 percent
Reaction: 7.8 to 8.4
COMPETING SERIES:
Michelson (MT) - has a buried argillic horizon below a depth of 40 inches.
Oro Fino (MT) - is sandy-skeletal at depths of 40 to 60 inches.
Philipsburg (MT) - does not have an O horizon.
GEOGRAPHIC SETTING:
Landform- mountains.
Elevation - 6,000 to 7,500 feet.
Slope - 15 to 45 percent.
Parent material - colluvium from limestone.
Climate - cool with long, cold winters; moist springs; short summers.
Mean annual precipitation - 20 to 24 inches.
Mean annual temperature - 34 to 38 degrees F.
Frost-free period - 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hanson, Tiban, and Whitore series. Tiban soils have a loamy skeletal control section, and lack both argillic and calcic horizons. Hanson soils have a loamy skeletal control section, lack an argillic horizon, and are carbonatic. Whitore soils have a loamy skeletal control section, lack both a mollic epipedon and an argillic horizon, and are carbonatic.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Accola soils are mainly used for timber production and understory grazing. The potential native vegetation is Douglas fir and common snowberry.
DISTRIBUTION AND EXTENT: Accola 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: MT1412. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from 1 to 9 inches (A, Bt1 horizons); an argillic horizon from 4 to 18 inches (Bt1, Bt2 horizons); a calcic horizon from 18 to 60 inches (Bk1, Bk2 horizons); a particle-size control section from 4 to 18 inches (Bt1, Bt2 horizons). Accola soils have a cryic temperature regime and an ustic moisture regime.