LOCATION EREMIS MTEstablished Series
TAXONOMIC CLASS: Ashy, glassy Ustivitrandic Haplocryepts
TYPICAL PEDON: Eremis gravelly ashy loam in forest (colors are for dry soil unless otherwise noted).
Oi--0 to 1 inch; partially decomposed needles, twigs and leaves.
A--1 to 3 inches; dark grayish brown (2.5Y 4/2) gravelly ashy loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; common very fine and fine roots and few medium roots; common fine and very fine pores; 20 percent gravel; strongly acid (pH 5.3); clear wavy boundary. (1 to 4 inches thick)
Bw--3 to 12 inches; light brownish gray (10YR 6/2) gravelly ashy loam, dark brown (10YR 3/3) moist; moderate medium prismatic structure; slightly hard, very friable, slightly sticky and nonplastic; many very fine and fine roots and common medium roots; many very fine and fine pores; 20 percent gravel; strongly acid (pH 5.4); gradual wavy boundary.
BC--12 to 25 inches; light gray (2.5Y 7/2) gravelly ashy sandy clay loam, dark grayish brown (2.5Y 4/2) moist; weak coarse prismatic structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots and few medium roots; common fine pores; 25 percent gravel; moderately acid (pH 6.0); gradual irregular boundary. (Combined thickness of B horizons is 18 to 30 inches.)
C1--25 to 36 inches; light brownish gray (2.5Y 6/2) gravelly ashy sandy clay loam, olive (5Y 4/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine pores; 20 percent gravel; slightly acid (pH 6.2); gradual irregular boundary.
C2--36 to 60 inches; light gray (N 7/) ashy sandy clay loam, olive (5Y 4/3) moist; massive; slightly hard, firm, slightly sticky and slightly plastic; 10 percent gravel; neutral (pH 6.6).
TYPE LOCATION: Deer Lodge County, Montana; 1500 feet east and 2100 feet north of the SW corner of sec. 16, T. 3 N., R. 11 W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 32 to 40 degrees F.
Mean summer soil temperature - 40 to 46 degrees F.
Moisture control section - between 4 and 12 inches.
Volcanic glass - 30 to 50 percent in the coarse silt and sand fraction.
Acid oxalate Al + 1/2 Fe - .12 to .20 percent
A horizon - Hue: 10YR or 2.5Y
Value: 3, 4, or 5 dry; 2 or 3 moist
Chroma: 1 or 2
Clay content: 15 to 25 percent
Rock fragments: 15 to 45 percent--0 to 15 percent cobbles and stones, 15 to 30 percent gravel
Reaction: pH 5.1 to 6.0
Bw horizon - Hue: 10YR or 2.5Y
Value: 5 or 6 dry, 3, 4 or 5 moist
Chroma: 1, 2 or 3
Texture: ashy loam or ashy sandy clay loam
Clay content: 18 to 27 percent
Rock fragments: 15 to 35 percent--0 to 5 percent cobbles and stones, 15 to 30 percent gravel
Reaction: pH 5.1 to 6.0
BC horizon - Value: 6 or 7 dry; 4, 5 or 6 moist
Chroma: 1, 2 or 3
Texture: ashy loam or ashy sandy clay loam
Clay content: 18 to 27 percent
Rock fragments: 15 to 35 percent--0 to 5 percent cobbles and stones; 15 to 30 percent gravel
Reaction: pH 5.6 to 6.5
C horizons - Hue: 2.5Y, 5Y or neutral
Value: 6, 7, or 8 dry; 4, 5, or 6 moist
Chroma: 1, 2 or 3
Texture: ashy sandy loam, ashy loam or ashy sandy clay loam
Clay content: 10 to 25 percent
Rock fragments: 10 to 35 percent--0 to 10 percent cobbles and stones; 10 to 25 percent gravel
Reaction: pH 6.1 to 7.3
COMPETING SERIES:
Bendoh (MT) - has a lithic contact at 40 to 60 inches.
Daras (MT) - has less than 18 percent clay in the particle-size control section.
GEOGRAPHIC SETTING:
Landform- alluvial fans, footslopes, mountains and hills.
Elevation - 5,500 to 8,000 feet.
Slope - 2 to 35 percent.
Parent material - colluvium and alluvium from welded tuff bedrock.
Climate - long, cold winters; cold, moist springs; short, cool summers.
Mean annual precipitation - 20 to 30 inches.
Mean annual air temperature - 30 to 37 degrees F.
Frost-free period - 30 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.
USE AND VEGETATION: Eremis soils are mainly used for woodland, watershed, and as wildlife habitat. The potential native vegetation is mainly subalpine fir, lodgepole pine, grouse whortleberry, elk sedge, dwarf huckleberry and pinegrass.
DISTRIBUTION AND EXTENT: Eremis soils are of small extent in southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Deer Lodge County, Montana, 1999.
REMARKS: Soil interpretive record: MT1747. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from 1 to 7 inches (A and upper part of the Bw horizons); a cambic horizon from 3 to 25 inches (Bw and BC horizons); a particle size control section from 10 to 40 inches (Bw, BC and C horizons). Eremis soils have a cryic temperature regime and an ustic moisture regime bordering on udic.
The 3/2008 description reflects a change in classification from Ashy, glassy Vitrandic Eutrocryepts to Ashy, glassy Ustivitrandic Haplocryepts due to revision of the cryepts great groups and subgroups. The competing series section was not updated and should be reviewed after all the cryepts have been re-classified.