LOCATION BONEBASIN MT
Established Series
Rev. DES-KTS-JCK
05/2013
BONEBASIN SERIES
The Bonebasin series consists of very deep, very poorly drained soils that formed in alluvium derived from mixed rock sources. These soils are on flood plains and stream terraces. Slopes are 0 to 4 percent. Mean annual precipitation is about 356 mm, and mean annual air temperature is about 4.4 degrees C.
TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, frigid Fluvaquentic Endoaquolls
TYPICAL PEDON: Bonebasin loam, in pasture (colors are for moist soil unless otherwise noted).
Oe--0 to 5 cm; black (10YR 2/1) mucky-peat, very dark grayish brown (10YR 3/2) dry; neutral (pH 6.8); clear smooth boundary. (0 to 10 cm thick)
A--5 to 20 cm; very dark gray (10YR 3/1) loam, dark gray (10YR 4/1) dry; many faint yellowish red (5YR 5/6) redox concentrations; moderate medium subangular blocky structure; slightly hard, firm, moderately sticky and slightly plastic; many very fine and fine roots; common very fine and fine interstitial and tubular pores; neutral (pH 6.8); clear smooth boundary.
Ag--20 to 38 cm; very dark grayish brown (2.5Y 3/2) loam, grayish brown (2.5Y 5/2) dry; many distinct yellowish red (5YR 5/6) redox concentrations; common faint very dark gray (5Y 3/1) redox depletions; moderate medium subangular blocky structure; slightly hard, very friable, moderately sticky and slightly plastic; many very fine roots; many very fine and fine pores; neutral (pH 6.7); clear smooth boundary. (combined thickness of A horizons is 25 to 60 cm)
Cg1--38 to 53 cm; brown (7.5YR 4/2) gravelly sandy loam, brown (7.5YR 5/2) dry; common distinct strong brown (7.5YR 5/6) redox concentrations; common faint very dark gray (5Y 3/1) redox depletions; massive; slightly hard, very friable, slightly sticky and nonplastic; many very fine roots; common very fine and fine interstitial and tubular pores; 25 percent gravel; neutral (pH 6.6).
Cg2--53 to 63 cm; dark brown (10YR 3/3) loam, grayish brown (10YR 5/2) dry; many distinct very dark gray (5Y 3/1) redox depletions; few faint yellowish red (5YR 5/6) redox concentrations; massive; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine and fine interstitial and tubular pores; 5 percent gravel; neutral (pH 6.7); clear smooth boundary. (Combined thickness of Cg horizons is 20 to 51 cm)
2C--63 to 152 cm; brown (7.5YR 4/2) extremely gravelly loamy sand and sand, brown (7.5YR 5/2) dry; common distinct yellowish red (5YR 5/6) redox concentrations; single grain; loose, nonsticky and nonplastic; few very fine and fine roots; 15 percent cobbles and 50 percent gravel; neutral (pH 6.8).
TYPE LOCATION: Jefferson County, Montana; 366 meters south and 457 meters west of the NE corner of sec. 4, T. 5 N., R. 4 W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 4.4 to 7.8 degrees C
Mollic epipedon thickness - 25 to 60 cm
Depth to seasonally high water table - 0 to 30 cm for extended periods during spring and summer
Depth to redoximorphic features - 0 to 10 cm
Depth to lithologic discontinuity - 51 to 102 cm
Note: Water table may drop to between 60 and 183 cm during late summer, fall and winter.
A and Ag horizons
Hue: 10YR, 2.5Y or 5Y; dry or moist
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 1 or 2; dry or moist
Texture: loam or sandy loam
Clay content: 15 to 27 percent
Rock fragments: 0 to 5 percent gravel
Electrical conductivity: 0 to 2 mmhos/cm
Calcium carbonate equivalent: 0 to 15 percent
Reaction: pH 6.6 to 8.4
Cg1 and Cg2 horizons
Hue: 10YR, 7.5YR, 2.5Y or 5Y; dry or moist
Value: 4 to 6 dry; 3, 4, or 5 moist
Chroma: 1 to 3; dry or moist
Texture: loam, silt loam or silty clay loam with strata of sandy loam, clay loam, or sand and gravel
Clay content: 18 to 35 percent
Rock fragments: 5 to 25 percent gravel
Calcium carbonate equivalent: 0 to 15 percent
Reaction: pH 6.6 to 8.4
2C horizon
Hue: 7.5YR, 10YR, 2.5Y or 5Y; dry or moist
Value: 4 to 6 dry; 3 to 5 moist
Chroma: 1 or 2; dry or moist
Texture: loamy sand, loamy coarse sand or sand
Clay content: 0 to 10 percent
Rock fragments: 35 to 70 percent--25 to 65 percent gravel, 10 to 20 percent cobbles
Electrical conductivity: 0 to 2 mmhos/cm
Sodium absorption ratio: 0 to 4
Reaction: pH 6.1 to 7.8
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - flood plains and stream terraces
Elevation - 1,128 to 1,890 meters
Slope - 0 to 4 percent
Parent material - alluvium derived from mixed rock sources
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 254 to 508 mm
Mean annual air temperature - 3.3 to 7.8 degrees C
Frost-free period - 70 to 120 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Very poorly drained, moderate permeability in the A and Cg horizons and rapid in the sandy-skeletal material.
USE AND VEGETATION: Bonebasin soils are primarily used for grass hay, pasture, and wetland wildlife habitat. The potential native vegetation is mainly tall reedgrasses, mannagrasses, American sloughgrass, tufted hairgrass sedges and rushes, blue-eyed grass, and willows.
DISTRIBUTION AND EXTENT: Bonebasin soils are of moderate extent in intermountain valleys of southwestern Montana. MLRAs 44B, 46, 58A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Gallatin County, Montana, 1997; proposed in Jefferson County, Montana, 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 5 to 38 cm (A and Ag horizons)
Redoximorphic features - from 5 to 63 cm (A, Ag, Cg1, and Cg2 horizons)
Lithologic discontinuity - at 63 cm (2C horizon)
Particle-size control section - from 30 to 105 cm (Ag, Cg1, Cg2, and 2C horizons)
Bonebasin soils have a frigid temperature regime and an aquic moisture regime.
ADDITIONAL DATA: Soil interpretation record - MT1570.
National Cooperative Soil Survey
U.S.A.