LOCATION HANSON MT+NV WY
Established Series
Rev. DES-KTS-RJS
12/2012
HANSON SERIES
The Hanson series consists of very deep, well drained soils that formed in alluvium, colluvium and glacial till derived from limestone rock. These soils are on stream terraces, alluvial fans, mountain slopes, hills and moraines. Slopes are 0 to 70 percent. Mean annual precipitation is about 23 inches and mean annual air temperature is about 40 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, carbonatic Calcic Haplocryolls
TYPICAL PEDON: Hanson loam, native grass (colors are for dry soil unless otherwise noted).
A1--0 to 8 inches; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; 5 percent gravel; neutral; gradual smooth boundary.
A2--8 to 14 inches; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; weak medium prismatic structure parting to weak fine and medium subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic, many very fine roots; many very fine tubular and interstitial pores; 10 percent limestone gravel; disseminated calcium carbonate; strongly effervescent; slightly alkaline; clear smooth boundary. (combined thickness of A horizons - 6 to 18 inches)
Bk1--14 to 26 inches; very pale brown (10YR 7/3) very cobbly loam, pale brown (10YR 6/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular and interstitial pores; 10 percent gravel, 50 percent cobbles; disseminated calcium carbonate, many masses of calcium carbonate, and continuous distinct calcium carbonate crusts on undersides of fragments; violently effervescent; slightly alkaline; diffuse smooth boundary. (5 to 20 inches thick)
Bk2--26 to 42 inches; pale yellow (2.5Y 8/4) extremely cobbly loam, light yellowish brown (2.5Y 6/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine roots; many very fine tubular and interstitial pores; 25 percent gravel, 55 percent cobbles; disseminated calcium carbonate, many masses of calcium carbonate, and continuous distinct calcium carbonate crusts on undersides of fragments; violently effervescent; moderately alkaline; gradual wavy boundary. (9 to 28 inches thick)
Bk3--42 to 60 inches; pale yellow (2.5Y 7/4) extremely cobbly loam, light yellowish brown (2.5Y 6/4) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular and interstitial pores; 10 percent gravel, 55 percent cobbles; disseminated calcium carbonate and continuous distinct calcium carbonate coatings on fragments; violently effervescent; moderately alkaline.
TYPE LOCATION: Cascade County, Montana; 2,380 feet east and 1,850 feet north of the SW corner of sec. 15, T. 17 N., R. 7 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 36 to 45 degrees F.
Mollic epipedon thickness - 7 to 16 inches
Depth to calcic horizon - 7 to 16 inches
Note: Some pedons may have a Bw horizon.
A1 horizon
Hue: 2.5Y, 10YR or 7.5YR; dry or moist
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 1 or 2; dry or moist
Texture: loam or clay loam
Clay content: 15 to 35 percent
Rock fragments: 5 to 50 percent--5 to 45 percent gravel or channers, 0 to 25 percent cobbles and stones
Reaction: pH 6.6 to 7.8
A2 horizon
Hue: 2.5Y, 10YR or 7.5YR; dry or moist
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 1 to 3; dry or moist
Texture: loam or clay loam
Clay content: 5 to 32 percent
Rock fragments: 5 to 55 percent--5 to 30 percent gravel or channers, 0 to 25 percent cobbles and stones
Calcium carbonate equivalent: 0 to 10 percent
Reaction: pH 6.6 to 8.4
Bk1, Bk2 horizons
Hue: 7.5YR, 10YR or 2.5Y; dry or moist
Value: 5 to 8 dry; 4 to 7 moist
Chroma: 2 to 4; dry or moist
Texture: loam or clay loam
Clay content: 15 to 32 percent
Rock fragments: 35 to 80 percent--10 to 50 percent gravel or channers, 5 to 55 percent cobbles and stones
Calcium carbonate equivalent: 30 to 40 percent in less than 2 mm particle-size fraction and more than 40 percent in the less than 20 mm soil particle-size fraction
Reaction: pH 7.4 to 8.4
Bk3 horizon
Hue: 7.5YR, 10YR or 2.5Y; dry or moist
Value: 7 or 8 dry; 5 or 6 moist
Chroma: 2 to 4; dry or moist
Texture: loam or clay loam
Clay content: 18 to 32 percent
Rock fragments: 35 to 90 percent--10 to 55 percent gravel or channers, 25 to 35 percent cobbles and stones
Calcium carbonate equivalent: 15 to 30 percent in the less than 2 mm particle-size fraction, more than 40 percent in the less than 20 mm fraction.
Reaction: pH 7.4 to 8.4
COMPETING SERIES:
Farlin (MT) - have an ustic moisture regime
Skaggs (MT) - have a lithic contact at depths of 20 to 40 inches
GEOGRAPHIC SETTING:
Landform - stream terraces, alluvial fans, mountain slopes, hills and moraines
Elevation - 4,800 to 8,000 feet
Slope - 0 to 70 percent
Parent material - alluvium, colluvium and glacial till derived from limestone rock
Climate - long, cold winters; moist springs; short summers
Mean annual precipitation - 15 to 30 inches
Mean annual air temperature - 34 to 43 degrees F.
Frost-free period - 30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Hanson soils are used mainly as rangeland; some areas are used for dryland crops. Potential native vegetation is mainly rough fescue, bluebunch wheatgrass, Richardson needlegrass, Columbia needlegrass, mountain brome, Idaho fescue, forbs, and shrubs.
DISTRIBUTION AND EXTENT: Hanson soils are of moderate extent in central and southwestern Montana. MLRAs - 25, 43B, 44B, 46.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Reconnaissance Soil Survey of central Montana, 1946.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 14 inches (A1, A2 horizons
Calcic horizon - from 14 to 60 inches (Bk1, Bk2, Bk3 horizons)
Particle-size control section - from 10 to 40 inches (part of A2, Bk1, part of Bk2 horizons)
Hanson soils have a cryic temperature regime and an udic moisture regime.
ADDITIONAL DATA: Soil interpretations records - MT0100, MT0767, MT0797, MT0158, MT0879.
National Cooperative Soil Survey
U.S.A.