LOCATION BLACKLAKE MTEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, nonacid, frigid Histic Humaquepts
TYPICAL PEDON: Blacklake mucky peat (colors are for moist soil unless otherwise noted).
Oe--0 to 9 inches; very dark brown (10YR 2/2) broken face and rubbed mucky peat (hemic material), about 70 percent fiber and raw herbaceous material, about 30 percent rubbed; weak thin platy structure parting to weak fine granular; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine roots; moderately acid (ph 5.8); clear smooth boundary.
Oe/C--9 to 14 inches; stratified black (10YR 2/1) broken face and rubbed mucky peat (hemic material) about 80 percent fiber and raw herbaceous material, about 30 percent rubbed (80 percent) and very dark gray (10YR 3/1) mucky silt loam (20 percent); moderate thin platy structure parting to moderate fine granular; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine roots; moderately acid (ph 5.8); abrupt wavy boundary. (Combined thickness of the Oe and Oe/C horizons is 10 to 15 inches.)
C/Oa--14 to 31 inches; stratified very dark grayish brown (10YR 3/2) mucky silt loam (70 percent), dark gray (10YR 4/1) silt loam (20 percent) and black (10YR 2/1) muck (10 percent); weak medium subangular blocky structure parting to weak very fine granular; slightly hard, very friable, nonsticky and nonplastic; common very fine and fine roots; moderately acid (ph 5.8); clear wavy boundary. (11 to 17 inches thick)
C--31 to 57 inches; stratified light brownish gray (10YR 6/2) very fine sandy loam and silt loam (70 percent) and light gray (10YR 7/2) silt (30 percent); massive; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; moderately acid (ph 6.0); abrupt wavy boundary. (17 to 30 inches thick)
C/Oa'--57 to 60 inches; stratified very dark gray (10YR 3/1) mucky silt loam (80 percent) and black (10YR 2/1) muck (20 percent); massive; slightly hard, friable, slightly sticky and slightly plastic; moderately acid (ph 6.0).
TYPE LOCATION: Flathead County, Montana; 1000 feet east and 400 feet north of the southwest corner of sec. 7, T. 26N., R. 26W.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F.
Histic epipedon thickness - 8 to 16 inches.
Depth to seasonal high water table: 0 to 12 inches.
Some pedons have a stratified mucky silt loam and silt loam A horizon instead of an Oe/C horizon.
Some pedons have C horizons instead of C/Oa horizons.
Oe horizon - Value: 2 or 3
Chroma: 1 or 2
Fiber content: 50 to 80 percent unrubbed, 20 to 30 percent rubbed
Reaction: pH 5.0 to 7.3
Oe/C horizon - Oe part: Value: 2 or 3
Chroma: 1 or 2
Fiber content: 50 to 80 percent unrubbed, 20 to 30 percent rubbed
Reaction: 5.6 to 7.3
C part - Value: 2 or 3 moist
Chroma: 1 or 2
Texture: silt loam or mucky silt loam
Clay content: 5 to 15 percent
Reaction: pH 5.0 to 7.3
C/Oa and C/Oa' horizons - C part: Hue: 10YR or 2.5Y
Value: 2, 3, 4, or 5
Chroma: 1 or 2
Texture: silt loam, mucky silt loam, silt, or very fine sandy loam
Clay content: 4 to 12 percent
Reaction: 5.6 to 6.5
Oa part: Fiber content: 30 to 50 percent unrubbed, less than 20 percent rubbed
Reaction: pH 5.6 to 6.5
C horizon - Hue: 10YR or 2.5Y
Value: 6 or 7
Chroma: 1 or 2
Clay content: 4 to 12 percent
Texture: silt, silt loam, or very fine sandy loam
Reaction pH 5.6 to 6.5
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform- depressions, backswamps, flood plains.
Elevation - 2,200 to 4,400 feet.
Slope - 0 to 1 percent.
Parent material - alluvium.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 18 to 30 inches, much of which falls as snow and spring rains.
Mean annual temperature - 41 to 45 degrees F.
Frost-free period - 70 to 95 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Very poorly drained, moderate permeability.
USE AND VEGETATION: Blacklake soils are used as wetland, drained pasture and hayland, and wildlife habitat. Potential native vegetation is mainly cattail, bullrush, sedges and cinquefoil.
DISTRIBUTION AND EXTENT: Blacklake soils are of limited extent in the valleys of northwestern Montana. LRR E. MLRA 43A and 44A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Flathead County, Montana 1997.
REMARKS: Soil Interpretation Record: MT1360. Diagnostic horizons and features recognized in this pedon are: a histic epipedon from the surface to 14 inches (Oe,Oe/C horizons); a particle size control section from 14 to 40 inches (C/Oa, and C horizons). Blacklake soils have a frigid temperature regime and an aquic moisture regime.