LOCATION BLACKCREEK MTEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, calcareous, frigid Typic Endoaquepts
TYPICAL PEDON: Blackcreek silt loam, forested (colors are for moist soil unless otherwise noted)
A--0 to 4 inches; black (10YR 2/1) silt loam, dark gray (10YR 4/1) dry; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium and few coarse roots; neutral (ph 7.2); clear wavy boundary. (3 to 5 inches thick)
Bw--4 to 10 inches; dark gray (10YR 4/1) silt, gray (10YR 6/1) dry; moderate medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots; neutral (ph 7.2); gradual wavy boundary. (7 to 10 inches thick)
Bk--10 to 27 inches; olive gray (5Y 5/2) silt loam, light gray (5Y 7/2) dry; weak medium subangular blocky structure; hard, firm, sticky and plastic; few medium roots; few fine faint brown (10YR 4/3) redox concentrations, moist; few fine masses of lime; slightly effervescent; slightly alkaline (ph 7.8); gradual wavy boundary. (10 to 26 inches thick)
C1--27 to 36 inches; gray (5Y 6/1) silt, white (5Y 8/1) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; common fine distinct brown (10YR 4/3) redox concentrations, moist; slightly effervescent; moderately alkaline (ph 8.0); gradual wavy boundary. (3 to 10 inches thick)
C2--36 to 42 inches; light gray (5Y 7/2) silt, pale yellow (5Y 8/2) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; many prominent medium yellowish brown (10YR 5/6) redox concentrations, moist; neutral (ph 6.8); gradual wavy boundary. (3 to 10 inches thick)
2C3--42 to 60 inches; gray (10YR 5/1) stratified loamy coarse sand and silt, gray (10YR 6/1) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; slightly acid (ph 6.3).
TYPE LOCATION: Lincoln County, Montana; 2,300 feet east and 300 feet south of the NW corner sec. 5, T. 26 N., R. 27 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Depth to water table - 12 to 24 inches.
A horizon - Value: 3 or 4 dry, 2 or 3 moist
Clay content: 12 to 18 percent
Reaction: pH 5.6 to 7.3
Bw horizon - Value: 3 or 4 moist, 5 or 6 dry
Texture: silt loam or silt
Clay content: 8 to 12 percent
Reaction: pH 6.1 to 7.3
Bk horizon - Value: 6 or 7 dry, 5 or 6 moist
Clay content: 8 to 12 percent
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.8 to 8.4
C1 horizon - Value: 7 or 8 dry, 6 or 7 moist
Texture: silt or silt loam
Clay content: 8 to 12 percent
Reaction: pH 7.4 to 8.4
C2 horizon - Value: 7 or 8 dry, 6 or 7 moist
Texture: silt or silt loam
Clay content: 0 to 10 percent
Reaction: pH 5.6 to 7.3
2C3 horizon - Value: 6 or 7 dry, 5 or 6 moist
Clay content: 0 to 10 percent
Reaction: pH 5.6 to 7.3
COMPETING SERIES:
There are no competing series.
GEOGRAPHIC SETTING:
Landform- stream terraces, outwash plains, outwash terraces and lake plains.
Elevation - 2,900 to 4,500 feet.
Slope - 0 to 4 percent.
Parent material - alluvium, outwash, lacustrine.
Climate - long, cold winters; moist springs; warm, dry summers.
Mean annual precipitation - 18 to 30 inches, much of which falls as snow and spring rain.
Mean annual air temperature - 42 to 45 degrees F.
Frost-free period - 70 to 95 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Poorly drained, moderate permeability.
USE AND VEGETATION: Blackcreek soils are used for woodland, understory grazing, and wildlife habitat. Potential native vegetation is mainly Engelmann spruce, white spruce, water birch, quaking aspen, and alder. Understory vegetation is mainly pinegrass, field horsetail, sedges, and forbs.
DISTRIBUTION AND EXTENT: Blackcreek soils are of small extent in the valleys of northwestern Montana. MLRA 43A, 44A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Lincoln County, Montana, 1997.
REMARKS: Soil interpretation record: MT1361. Diagnostic horizons and features recognized in this pedon are: a mollic surface from the soil surface to 4 inches (A horizon); a calcic horizon from 10 to 27 inches (Bk horizon); and a particle-size control section from 10 to 40 inches (Bk, C1, and C2 horizons). Blackcreek soils have a frigid temperature regime and an aquic moisture regime.
Classification was changed from Typic Haplaquepts to Typic Endoaquepts in 1993.
ADDITIONAL DATA: Laboratory data S92MT-053-007.