LOCATION CAMASCREEK MTEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, frigid Aquic Natrixerolls
TYPICAL PEDON: Camascreek silt loam in range. (Colors are for dry soil unless otherwise noted)
A1--0 to 8 inches; gray (10YR 5/1) silt loam, very dark gray (10YR 3/1) moist; moderate medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine and common medium roots; many very fine and fine pores; strongly effervescent, disseminated lime; very strongly alkaline (pH 9.2); clear smooth boundary. (7 to 14 inches thick)
A2--8 to 15 inches; brown (10YR 5/3) silty clay loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure parting to strong very fine and fine angular blocky; slightly hard, firm, slightly sticky and moderately plastic; common fine and medium and few coarse roots; few very fine pores; violently effervescent, disseminated lime; strongly alkaline (pH 8.8); clear smooth boundary. (0 to 8 inches thick)
Btkn1--15 to 23 inches; pale brown (10YR 6/3) silty clay, brown (10YR 4/3) moist; weak medium prismatic structure parting to strong fine and medium angular and subangular blocky; very hard, very firm, moderately sticky and very plastic; few fine roots; common very fine and fine pores; common distinct clay films on faces of peds and in pores; strongly effervescent, common fine soft masses of lime; moderately alkaline (pH 8.4); gradual smooth boundary. (7 to 12 inches thick)
Btkn2--23 to 43 inches; pale brown (10YR 6/3) silty clay, brown (10YR 4/3) moist; common faint grayish brown (2.5Y 5/2) redox depletions; weak medium and coarse subangular blocky structure; hard, very firm, moderately sticky and very plastic; few fine roots; common fine and medium pores; few distinct clay films on faces of peds; strongly effervescent, many fine soft masses of lime; moderately alkaline (pH 8.2); gradual smooth boundary. (8 to 22 inches thick)
BC--43 to 60 inches; light yellowish brown (10YR 6/4) silty clay, dark yellowish brown (10YR 4/4) moist; common distinct grayish brown (2.5Y 5/2) redox depletions; massive; very hard, very firm, moderately sticky and very plastic; few fine pores; slightly effervescent, disseminated lime; moderately alkaline (pH 8.0).
TYPE LOCATION: Sanders County, Montana; 250 feet north and 1750 feet east of the southwest corner of section 26, T. 20 N., R. 24 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 46 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 16 inches.
Depth to secondary carbonates horizon - 10 to 20 inches.
Depth to seasonal high water table - 24 to 42 inches.
In some pedons the surface 1 to 2 inches is noncalcareous but when mixed to a depth of seven inches the surface layer is calcareous throughout.
A1 horizon - Value: 4 or 5 dry; 2 or 3 moist
Chroma: 1 or 2
Clay content: 20 to 27 percent
Calcium carbonate equivalent: 3 to 10 percent
EC: 0 to 4 mmhos/cm
SAR: 13 to 40
Reaction: pH 8.5 to 9.6
A2 horizon - Value: 5 or 6 dry; 3 or 4 moist
Chroma: 2 or 3
Texture: silt loam or silty clay loam
Clay content: 20 to 35 percent
Calcium carbonate equivalent: 5 to 10 percent
EC: 0 to 4 mmhos/cm
SAR: 13 to 30
Reaction: pH 8.5 to 9.0
Btkn1 horizon - Value: 6 or 7 dry; 4 or 5 moist
Chroma: 3 or 4
Texture: silty clay or silty clay loam
Clay content: 35 to 60 percent
Calcium carbonate equivalent: 3 to 8 percent
EC: 0 to 4 mmhos/cm
SAR: 10 to 20
Reaction: pH 7.9 to 9.0
Btkn2 horizon - Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 4 or 5 moist
Chroma: 3 or 4
Texture: silty clay or silty clay loam
Clay content: 35 to 55 percent
Calcium carbonate equivalent: 1 to 3 percent
EC: 0 to 4 mmhos/cm
SAR: 0 to 13
Reaction: pH 7.9 to 8.4
BC horizon - Hue: 10YR or 2.5Y
Value: 5, 6 or 6 dry; 4, 5 or 6 moist
Chroma: 1, 2, 3, of 4
Texture: silty clay or silty clay loam
Clay content: 35 to 55 percent
Calcium carbonate equivalent: 0 to 1 percent
EC: 0 to 4 mmhos/cm
SAR: 0 to 13
Reaction; pH 7.4 to 8.4
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform- alluvial fans, stream terraces and drainageways.
Elevation - 2,700 to 3,100 feet.
Slope - 0 to 2 percent
Parent material - alluvium.
Climate - long cold winters, moist springs, and warm, dry summers.
Mean annual precipitation - 10 to 16 inches, much of which falls as snow and spring rains.
Mean annual temperature - 41 to 45 degrees F.
Frost-free period is 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; very slow permeability.
USE AND VEGETATION: These soils are used mainly as range and grass pasture with some small areas as irrigated cropland. The native vegetation is mainly basin wildrye and nuttall alkaligrass.
DISTRIBUTION AND EXTENT: Camascreek soils are inextensive in mountain valleys of western Montana. MLRA 44A
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Sanders County, Montana, 1997.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 15 inches (A1 and A2 horizons);
Natric horizon - from 15 to 23 inches (Btkn1 horizon);
Accumulations of secondary carbonates - from 15 to 43 inches (Btkn1 and Btkn2 horizons);
Particle size control section - from 15 to 35 inches (Btkn1 and part of the Btkn2 horizons).
Camascreek soils have a frigid temperature regime and a Xeric moisture regime that borders on Aquic.
Soil interpretation record: MT1142.