LOCATION LONEMAN MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Andic Paleudalfs
TYPICAL PEDON: Loneman ashy silt loam, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 2 inches; undecomposed and slightly decomposed forest litter.
A--2 to 3 inch; grayish brown (10YR 5/2) ashy silt loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure parting to moderate fine granular; soft, very friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; 10 percent pebbles; neutral (pH 6.6); abrupt wavy boundary. (0 to 1 inches thick)
Bw--3 to 11 inches; light yellowish brown (10YR 6/4) ashy silt loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure parting to moderate fine granular; soft, very friable, slightly sticky and slightly plastic; common very fine and fine and few medium roots; 10 percent pebbles; slightly acid (pH 6.4); abrupt wavy boundary. (6 to 9 inches thick)
2E--11 to 28 inches; light brownish gray (2.5Y 6/2) very gravelly loam, grayish brown (2.5Y 5/2) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and fine and few medium and coarse roots; 10 percent cobbles, 40 percent pebbles; neutral (pH 6.8); gradual wavy boundary. (14 to 28 inches thick)
2E/Bt--28 to 42 inches; E part (70 percent) is very pale brown (10YR 8/3) very gravelly loam, very pale brown (10YR 7/3) moist, Bt part (30 percent) is light yellowish brown (10YR 6/4) very gravelly clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few fine and medium and common coarse roots; common distinct clay films on faces of peds; 10 percent cobbles, 40 percent pebbles; neutral (pH 6.8); gradual wavy boundary. (9 to 23 inches thick)
2Bt--42 to 60 inches; brownish yellow (10YR 6/6) very gravelly clay loam, yellowish brown (10YR 5/6) moist; moderate medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common medium and coarse roots; many distinct clay films on faces of peds; 10 percent cobbles, 40 percent pebbles; neutral (pH 6.8).
TYPE LOCATION: Sanders County, Montana; 1,500 feet east and 2,200 feet north of the SW corner of sec. 33, T. 22 N., R. 26 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 40 to 45 degrees F.
A horizon - Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2, 3 or 4
Clay content: 2 to 10 percent
Rock Fragments: 0 to 15 percent pebbles
Acid oxalate extractable Al + 1/2 Fe: 1 to 1.5 percent
Bulk density: 0.85 to 1.0 g/cc
Reaction: pH 5.6 to 7.3
Bw horizon - Value: 6 or 7 dry; 4, 5, or 6 moist
Chroma: 4 or 6
Clay content: 2 to 10 percent
Rock Fragments: 0 to 15 percent--0 to 5 percent cobbles, 0 to 10 percent pebbles
Acid oxalate extractable Al + 1/2 Fe: 1 to 1.5 percent
Bulk density: 0.85 to 1.0 g/cc
Reaction: pH 5.6 to 7.3
2E horizon - Hue: 10YR or 2.5Y
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 2, 3 or 4
Clay content: 5 to 15 percent
Rock Fragments: 35 to 60 percent--5 to 15 percent cobbles, 30 to 45 percent pebbles
Reaction: pH 5.6 to 7.3
2E/Bt horizon - Hue: E part 7.5YR, 10YR, or 2.5Y, B part 7.5YR or 10YR
Value: E part 6, 7 or 8 dry, 5 or 6 moist; B part 6 or 7 dry, 4, 5 or 6 moist
Chroma: E part 3, 4, 6 or 8; B part 4 or 6
Texture: loam, clay loam
Clay content: 10 to 30 percent
Rock Fragments: 35 to 60 percent--5 to 10 percent cobbles, 30 to 50 percent pebbles
Reaction: 5.6 to 7.3
2Bt horizon - Hue: 7.5YR or 10YR
Value: 6 or 7 dry, 5, 6 or 7 moist
Chroma: 6 or 8
Clay content: 20 to 35 percent
Rock Fragments: 35 to 60 percent--10 to 20 percent cobbles, 25 to 40 percent pebbles
Reaction: pH 5.6 to 7.3
COMPETING SERIES:
Loonlake (MT) - has more than 60 percent coarse fragments in the particle-size control section; formed in glacial outwash.
Noxlin (MT) -does not have a 2Bt horizon; formed in mixed alluvium and glacial outwash.
GEOGRAPHIC SETTING:
Landform - mountains.
Elevation - 3,600 to 4,600 feet.
Slope - 15 to 60 percent.
Parent material - volcanic ash over colluvium.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 25 to 40 inches, much of which falls as snow and spring rains.
Mean annual temperature - 39 to 44 degrees F.
Frost-free period - 70 to 90 days.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.
USE AND VEGETATION: Loneman soils are used mainly for woodland, understory grazing, and wildlife habitat. Potential native vegetation is mainly Douglas fir, western larch, lodgepole pine, and grand fir. Understory vegetation is mainly pinegrass, twinflower, russet buffaloberry, blue huckleberry, and other forbs and shrubs.
DISTRIBUTION AND EXTENT: Loneman soils are of small extent in the mountains of northwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Sanders County, Montana, 1997.
REMARKS: Soil interpretation record: MT1387. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the mineral soil surface to 7 inches, mixed (A, Bw horizons); an ash influenced layer from 2 to 11 inches (A, Bw horizons); an albic horizon from 11 to 28 inches (2E horizon); a glossic horizon from 28 to 42 inches (2E/Bt horizon); an argillic horizon from 42 to 60 inches (2Bt horizon); a particle-size control section from 42 to 60 inches (2Bt horizon). Loneman soils have a udic moisture regime and a frigid temperature regime.
ADDITIONAL DATA: Laboratory data S92MT-89-007