LOCATION MACABRE MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Vitrandic Argiustolls
TYPICAL PEDON: Macabre very cobbly ashy sandy clay loam , in non-stocked forest (colors are for dry soil unless otherwise noted).
A--0 to 9 inches; gray (10YR 5/1) very cobbly ashy sandy clay loam, very dark grayish brown (10YR 3/2) moist; moderate very fine and fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots; 15 percent cobbles and 25 percent pebbles; slightly alkaline (pH 7.4); clear wavy boundary. (6 to 10 inches thick)
Bt--9 to 17 inches; grayish brown (2.5Y 5/2) very cobbly ashy sandy clay loam, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots, common medium roots and few coarse roots; many medium tubular pores; common distinct clay films on faces of peds; 15 percent cobbles and 25 percent pebbles; slightly alkaline (pH 7.6); gradual wavy boundary. (6 to 14 inches thick)
BC--17 to 27 inches; light brownish gray (2.5Y 6/2) very cobbly ashy sandy clay loam, light olive brown (2.5Y 5/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots, few medium and coarse roots; common medium tubular pores; 20 percent cobbles and 25 percent pebbles; slightly alkaline (pH 7.8); gradual irregular boundary. (5 to 15 inches thick)
Cr--27 to 41 inches; light gray (N 7/) decomposing welded tuff bedrock. (10 to 20 inches thick)
R--41 inches; light gray (5Y 7/1) fractured hard welded tuff bedrock.
TYPE LOCATION: Deer Lodge County, Montana; 1300 feet west and 1800 feet south of the NE corner of sec. 35, T. 4 N., R. 11 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 38 to 42 degrees F.
Moisture control section - between 4 and 12 inches.
Volcanic glass - 23 to 30 percent.
Al + 1/2 Fe - .11 to .20
Mollic epipedon thickness - 7 to 10 inches.
Depth to argillic horizon - 6 to 12 inches.
Depth to Cr horizon - 20 to 40 inches.
Depth to R horizon - 40 to 60 inches.
Surface stones or boulders - 0 to 3 percent
A horizon - Hue: 10YR or 2.5Y
Value: 3, 4 or 5 dry; 2 or 3 moist
Chroma: 1 or 2
Texture: ashy loam or ashy sandy clay loam
Clay content: 18 to 27 percent
Rock fragments: 15 to 45 percent--5 to 15 percent cobbles and stones, 10 to 30 percent pebbles
Reaction: pH 6.1 to 7.8
Bt horizon - Hue: 10YR or 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 or 3
Texture: ashy loam, ashy clay loam or ashy sandy clay loam
Clay content: 23 to 30 percent
Rock fragments: 35 to 60 percent--5 to 25 percent cobbles and stones, 25 to 35 percent pebbles
Reaction: pH 5.6 to 7.8
BC horizon - Hue: 10YR, 2.5Y or 5Y
Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Chroma: 1, 2, 3 or 4
Texture: ashy loam, ashy sandy loam or ashy sandy clay loam
Clay content: 15 to 25 percent
Rock fragments: 35 to 60 percent--10 to 25 percent cobbles and stones; 25 to 35 percent pebbles
Reaction: pH 5.6 to 7.8
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - hills; mountains.
Elevation - 4,500 to 6,600 feet.
Slope - 4 to 60 percent.
Parent material - residuum, colluvium and slope alluvium from welded tuff or ryolite bedrock.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 15 to 24 inches.
Mean annual air temperature - 36 to 40 degrees F.
Frost-free period - 70 to 95 days.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.
USE AND VEGETATION: Macabre soils are mainly used for woodland, rangeland, watershed, and as wildlife habitat. The potential native vegetation is mainly lodgepole pine, Douglas-fir, Rocky Mountain juniper, Oregongrape, common snowberry, bitterbrush, quaking aspen, sandberg bluegrass, tufted hairgrass, bluebunch wheatgrass, Idaho fescue, lupine and rose.
DISTRIBUTION AND EXTENT: Macabre soils are of small extent in southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jefferson County, Montana, 1998; proposed in Deer Lodge County, Montana, 1996.
REMARKS: Soil interpretation record: MT1730, MT3232, MT3233. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the surface to 9 inches (A horizon); an argillic horizon from 9 to 17 inches (Bt horizon); a particle size control section from 9 to 17 inches (Bt horizon); a layer of decomposing welded tuff from 27 to 41 inches (Cr horizon); welded tuff bedrock at 41 inches (R horizon). Macabre soils have a frigid temperature regime and an ustic moisture regime.