LOCATION CARETT MTEstablished Series
TAXONOMIC CLASS: Ashy, glassy, frigid Vitrandic Argiustolls
TYPICAL PEDON: Carett very cobbly ashy silty clay loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 9 inches; very dark gray (10YR 3/1) very cobbly ashy silty clay loam, black (10YR 2/1) moist; moderate fine granular structure; slightly hard, very friable, moderately sticky and moderately plastic; many very fine and fine roots; few very fine tubular pores; 20 percent pebbles and 30 percent cobbles; neutral (pH 7.0); clear smooth boundary.(8 to 12 inches thick)
Bt1--9 to 15 inches; brown (10YR 4/3) cobbly ashy silty clay loam, dark brown (10YR 3/3) moist; strong medium subangular blocky structure; very hard, very friable, moderately sticky and moderately plastic; many very fine and fine roots; few medium tubular pores; common distinct clay films on faces of peds; 10 percent pebbles and 15 percent cobbles; neutral (pH 7.0); gradual smooth boundary. (6 to 14 inches thick)
Bt2--15 to 24 inches; brown (10YR 5/3) cobbly ashy silty clay loam, brown (10YR 4/3) moist; moderate fine subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; many very fine and common fine roots; few medium tubular pores; common distinct clay films on faces of peds and lining pores; 10 percent pebbles and 15 percent cobbles; slightly alkaline (pH 7.4); clear wavy boundary. (6 to 14 inches thick)
Cr--24 to 60 inches; very pale brown (10YR 7/3) semiconsolidated tuff that crushes to silt loam.
TYPE LOCATION: Granite County, Montana: 1,600 feet east and 2,550 feet south of the NW corner of section 25, T. 5 N., R. 15 W.
RANGE IN CHARACTERISTICS:
Soil Temperature - 41 to 46 degrees F.
Moisture control section - between 4 and 12 inches
Mollic epipedon thickness - 8 to 15 inches
Depth to argillic horizon - 8 to 12 inches
Depth to Cr horizon - 20 to 40 inches
A horizon - Value: 3 or 4 dry; 2 or 3 moist
Chroma: 1 or 2
Texture: silty clay loam, clay or silty clay
Clay content: 35 to 50 percent
Rock fragments: 35 to 60 percent--25 to 35 cobbles and 10 to 25 percent pebbles
Bulk density: 1.15 to 1.35 g/cc
AOE Al + 1/2 Fe: 0.2 to 0.4 percent
Reaction: pH 6.6 to 7.3
Bt1 horizon - Value: 4 or 5 dry; 3 or 4 moist
Chroma: 2 or 3
Texture: silty clay loam, clay or silty clay
Clay content: 35 to 50 percent
Rock fragments: 15 to 35 percent--10 to 20 percent cobbles and 5 to 15 percent pebbles
Bulk density: 1.35 to 1.45 g/cc
AOE Al + 1/2 Fe: 0.2 to 0.4 percent
Volcanic glass: 40 to 50 percent
Reaction: pH 6.6 to 7.3
Bt2 horizon - Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4
Texture: silty clay loam, clay or silty clay
Clay content: 35 to 50 percent
Rock fragments: 15 to 35 percent--10 to 20 percent cobbles and 5 to 15 percent pebbles
Bulk density: 1.35 to 1.45 g/cc
AOE Al + 1/2 Fe: 0.2 to 0.4 percent
Volcanic glass: 40 to 50 percent
Reaction: pH 6.6 to 7.8
COMPETING SERIES:
There are no competing series.
GEOGRAPHIC SETTING:
Landform - alluvial fans and stream terraces.
Elevation - 4,000 to 6,300 feet.
Slope - 15 to 35 percent.
Parent material - alluvium or colluvium derived from semiconsolidated tuff.
Climate - long, cold winters; cool, moist springs; warm summers.
Mean annual precipitation - 15 to 19 inches.
Mean annual air temperature - 39 to 44 degrees F.
Frost-free period - 70 to 90 days.
DRAINAGE AND PERMEABILITY: Well drained, moderately slow permeability.
USE AND VEGETATION: Carett soils are primarily used for rangeland. The potentional native vegetation is mainly bluebunch wheatgrass, Idaho fescue and rough fescue.
DISTRIBUTION AND EXTENT: Carett soils are of small extent in southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Granite County, Montana, 1997.
REMARKS: Soil interpretation record MT1519. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the surface to 15 inches (A and Bt1 horizons); an argillic horizon from 9 to 24 inches (Bt1 and Bt2 horizons); a paralithic contact at 24 inches (Cr horizon); a particle size control section from 9 to 24 inches (Bt1 and Bt2 horizons). Carett soils have a frigid temperature regime and an ustic moisture regime.
ADDITIONAL DATA: NSSL S89MT-039-1297.