LOCATION NOXLIN MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Andic Paleudalfs
TYPICAL PEDON: Noxlin ashy silt loam, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 2 inches; undecomposed and slightly decomposed forest litter. (1 to 2 inches thick)
A--2 to 3 inches; brown (10YR 5/3) ashy silt loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, common fine and medium, and few coarse roots; slightly acid (pH 6.4); clear wavy boundary. (0 to 2 inches thick)
Bw--3 to 12 inches; light yellowish brown (10YR 6/4) ashy silt loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure parting to moderate fine granular; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and medium and few coarse roots; 5 percent pebbles; slightly acid (pH 6.2); clear wavy boundary. (7 to 11 inches thick)
2E--12 to 28 inches; very pale brown (10YR 8/2) very gravelly loam, light brownish gray (10YR 6/2) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium and few coarse roots; 10 percent cobbles, 35 percent pebbles; neutral (pH 7.0); gradual wavy boundary. (12 to 20 inches thick)
2E/Bt--28 to 40 inches; E part (70 percent) is very pale brown (10YR 8/2) very gravelly loam, light brownish gray (10YR 6/2) moist, Bt part (30 percent) is pink (7.5YR 7/4) very gravelly loam, brown (7.5YR 5/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium and coarse roots; common distinct clay films on faces of peds; 5 percent cobbles, 45 percent pebbles; neutral (pH 6.8); gradual wavy boundary. (10 to 16 inches thick)
2Bt/E--40 to 60 inches; Bt part (70 percent) is pink (7.5YR 7/4) very gravelly loam, brown (7.5YR 5/4) moist, E part (30 percent) is very pale brown (10YR 8/2) very gravelly loam, light brownish gray (10YR 6/2) moist; moderate fine and medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few coarse roots; many distinct clay films on faces of peds; 10 percent cobbles, 45 percent pebbles; neutral (pH 6.8).
TYPE LOCATION: Sanders County, Montana; 2,000 feet south and 2,100 feet east of the NW corner of sec. 34, T. 24 N., R. 31 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F
Moisture control section - between 8 and 24 inches.
A horizon - Value: 4, 5, or 6 dry; 3, 4, or 5 moist
Clay content: 5 to 15 percent
Rock fragments: 0 to 15 percent pebbles
Bulk density: .85 to 1.0 g/cc
Acid oxalate (Al + 1/2 Fe): 1.0 to 1.5 percent
Reaction: 5.6 to 6.5
Bw horizon - Value: 5 or 6 dry, 4 or 5 moist
Clay content: 5 to 15 percent
Rock fragments: 0 to 15 percent pebbles
Bulk density: .85 to 1.0 g/cc
Acid oxalate (Al + 1/2 Fe): 1.0 to 2.0 percent
Reaction: 5.6 to 6.5
2E horizon - Value: 5, 6, 7, or 8 dry; 4, 5, or 6 moist
Clay content: 5 to 15 percent
Rock fragments: 35 to 55 percent--5 to 15 percent cobbles, 30 to 40 percent pebbles
Reaction: 5.6 to 7.3
2E/Bt horizon - Hue: E part 10YR, Bt part 10YR or 7.5YR
Value: E part 6, 7, or 8, Bt part 5, 6, or 7 dry; E part 5, 6, or 7, B part 4, 5, or 6 moist
Clay content: E part 8 to 18 percent, Bt part 18 to 27 percent
Rock fragments: 40 to 60 percent--5 to 15 percent cobbles, 35 to 45 percent pebbles
Reaction: 5.6 to 7.3
2Bt/E horizon - Hue: Bt part 10YR or 7.5YR, E part 10YR
Value: Bt part 5, 6, or 7, E part 6, 7, or 8 dry; Bt part 4, 5, or 6, E part 5, 6, or 7 moist
Clay content: Bt part 18 to 27 percent, E part 8 to 18 percent
Rock fragments: 40 to 60 percent--5 to 15 percent cobbles, 35 to 45 percent pebbles
Reaction: 5.6 to 7.3
COMPETING SERIES:
Loneman (MT) - has a 2Bt horizon; formed in colluvium.
Loonlake (MT) - has more than 60 percent coarse fragments in the particle-size control section; does not have a glossic horizon extending below a depth of 30 inches.
GEOGRAPHIC SETTING:
Landform - stream terraces in valleys.
Elevation - 2,200 to 2,700 feet.
Slope - 4 to 35 percent.
Parent material - volcanic ash over mixed alluvium and glacial outwash.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 28 to 32 inches.
Mean annual air temperature - 42 to 45 degrees F.
Frost-free period - 90 to 105 days.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.
USE AND VEGETATION: Noxlin soils are used mainly for woodland, understory grazing, and wildlife habitat. Potential native vegetation is mainly Douglas fir, western larch, lodgepole pine, grand fir, western white pine, western red cedar, and western hemlock. Understory vegetation is mainly common snowberry, pinegrass, oceanspray, blue huckleberry, queen cup beadlily, sweetscented bedstraw, and other forbs and shrubs.
DISTRIBUTION AND EXTENT: Noxlin soils are of limited extent in the valleys of northwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Sanders County, Montana 1997.
REMARKS: Soil interpretation record: MT1382. Diagnostic horizons and features recognized in this pedon are: an ash influenced layer from 2 to 12 inches (A, Bw horizons); an ochric epipedon from the mineral soil surface to 7 inches mixed (A, Bw horizons); an albic horizon from 12 to 28 inches (2E horizon); a glossic horizon from 28 to 40 inches (2E/Bt horizon); an argillic horizon from 40 to 60 inches (2Bt/E horizon); a particle-size control section from 40 to 60 inches (2Bt/E horizon). Noxlin soils have a udic moisture regime and a frigid temperature regime.
ADDITIONAL DATA: Laboratory data S92MT-089-004.