LOCATION CLUNTON MT
Established Series
Rev. DES-JAL-JCK
05/2013
CLUNTON SERIES
The Clunton series consists of very deep, very poorly drained soils that formed alluvium. These soils are on flood plains, flood-plain steps, and drainageways. Slopes are 0 to 4 percent. Mean annual precipitation is about 356 mm. Mean annual air temperature is about 6 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Fluvaquentic Endoaquolls
TYPICAL PEDON: Clunton silty clay loam, in hay meadow (Colors are for moist soil unless otherwise noted).
Oe--0 to 10 cm; very dark gray (5Y 3/1) mucky-peat, very dark gray (5Y 3/1) dry; neutral (pH 6.8); clear smooth boundary. (0 to 10 cm thick)
Ag--10 to 46 cm; very dark gray (10YR 3/1) silty clay loam, dark gray (10YR 4/1) dry; many distinct black (5Y 2.5/1) redox depletions; few faint strong brown (7.5YR 5/6) redox concentrations; moderate medium prismatic structure; hard, firm, moderately sticky and moderately plastic; common very fine roots; common very fine and fine interstitial pores; neutral (pH 7.0); abrupt smooth boundary. (25 to 60 cm thick)
Cg1--46 to 76 cm; very dark gray (5Y 3/1) silty clay loam, dark gray (5Y 4/1) dry; common faint very dark gray (5Y 3/1) redox depletions; many distinct strong brown (7.5YR 5/6) redox concentrations; massive; hard, firm, moderately sticky and moderately plastic; common very fine roots; few very fine tubular pores; neutral (pH 7.2); clear wavy boundary. (20 to 51 cm thick)
Cg2--76 to 86 cm; very dark gray (5Y 3/1) loam consisting of strata of loam and sandy loam, dark gray (5Y 4/1) dry; common distinct strong brown (7.5YR 5/6) redox concentrations; common faint very dark gray (5Y 3/1) redox depletions; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots; neutral (pH 7.2); gradual wavy boundary. (0 to 20 cm thick)
Cg3--86 to 107 cm; dark gray (5Y 4/1) silty clay loam consisting of strata of silty clay loam and sandy loam, gray (5Y 5/1) dry; common distinct strong brown (7.5YR 5/6) redox concentrations; common faint very dark gray (5Y 3/1) redox depletions; massive; slightly hard, friable, slightly sticky and slightly plastic; neutral (pH 7.0); gradual wavy boundary. (0 to 30 cm thick)
2Cg4--107 to 163 cm; dark gray (10YR 4/1) gravelly sandy loam, grayish brown (2.5Y 5/2) dry; many distinct strong brown (7.5YR 5/6) redox concentrations; few faint very dark gray (5Y 3/1) redox depletions; massive; slightly hard, friable, slightly sticky and nonplastic; 15 percent gravel; neutral (pH 7.0).
TYPE LOCATION: Jefferson County, Montana; 488 meters north and 366 meters west of the SE corner of sec. 30, T. 4 N., R. 2 W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 4.4 to 7.8 degrees C
Mollic epipedon thickness - 25 to 60 cm
Depth to seasonal high water table - 0 to 30 cm for extended periods during spring and summer
Depth to redoximorphic features - 0 to 10 cm
Particle-size control section (weighted average) - 18 to 27 percent clay
Ag horizon
Hue: 10YR, 2.5Y or 5Y
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 1 or 2
Texture: silty clay loam, loam or silt loam
Clay content: 15 to 30 percent
Electrical conductivity: 0 to 2 mmhos/cm
Reaction: pH 6.1 to 7.3
Cg1 horizon
Hue: 10YR, 2.5Y or 5Y
Value: 4 or 5 dry
Chroma: 1 or 2
Texture: silty clay loam, loam, silt loam, or clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 10 percent gravel
Electrical conductivity: 0 to 2 mmhos/cm
Reaction: pH 6.6 to 7.8
Cg2 and Cg3 horizons
Hue: 2.5Y or 5Y
Value: 4, 5 or 6 dry; 3, 4 or 5 moist
Texture: silt loam, loam, clay loam or silty clay loam with thin strata of finer and coarser materials.
Clay content: 18 to 35 percent
Rock fragments: 0 to 10 percent gravel
Electrical conductivity: 0 to 2 mmhos/cm
Reaction: pH 6.6 to 7.8
2Cg4 horizon
Hue: 10YR, 2.5Y, 5Y or N
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 0, 1 or 2
Texture: sandy loam or loam with strata of loamy sand, silt loam or very fine sandy loam
Clay content: 5 to 25 percent
Rock fragments: 0 to 25 percent gravel
Electrical conductivity: 0 to 4 mmhos/cm
Reaction: pH 6.6 to 7.8
COMPETING SERIES:
Fairbirch (MT) - have a cambic horizon; have more than 35 percent rock fragments in the subsoil
Hayspur (NV) - have Mn oxide concretions; have more than 35 percent rock fragments in the lower part of the subsoil
Moynier (UT) - have a weighted average of more than 27 percent clay in the particle-size control section
GEOGRAPHIC SETTING:
Landform - flood plains, flood-plain steps, and drainageways
Elevation - 1,128 to 1,830 meters
Slope - 0 to 4 percent
Parent material - alluvium
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 250 to 480 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 to a depth of 106 cm and moderately rapid below.
USE AND VEGETATION: Clunton soils are primarily used for native grass hay, pasture, and wetland wildlife habitat. The potential native vegetation is mainly tall reedgrass, mannagrass, American sloughgrass, tufted hairgrass, sedges and rushes, blue-eyedgrass and willows.
DISTRIBUTION AND EXTENT: Clunton soils are of moderate extent in the intermountain valleys and foothills of southwestern Montana. MLRAs 43B, 44B, 46, 58A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jefferson County, Montana, 1998.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 10 to 36 cm (Ag horizon)
Redoximorphic features - from 10 to 163 cm (Ag, Cg1, Cg2, Cg3, and Cg4 horizons
Particle size control section - from 35 to 110 cm (Ag, Cg1, Cg2, Cg3, and 2Cg4 horizons)
Clunton soils have a frigid temperature regime and an aquic moisture regime.
ADDITIONAL DATA: Soil interpretations record - MT1557
National Cooperative Soil Survey
U.S.A.