LOCATION FESSLER MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Pachic Argiustolls
TYPICAL PEDON: Fessler gravelly loam, forested (colors are for dry soil unless otherwise noted).
Oi-0 to 3 inches; slightly decomposed forest litter. (1 to 3 inches thick)
A1--3 to 7 inches; black (10YR 2/1) gravelly loam, black (10YR 2/1) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine, and medium roots; many very fine irregular pores; 5 percent cobbles and 15 percent pebbles; slightly acid (pH 6.2); clear smooth boundary. (4 to 6 inches thick)
A2--7 to 13 inches; very dark gray (10YR 3/1) very gravelly clay loam, black (10YR 2/1) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, fine and medium roots and common coarse roots; many very fine irregular pores; 15 percent cobbles and 30 percent pebbles; slightly acid (pH 6.4); clear smooth boundary. (5 to 8 inches thick)
Bt1--13 to 32 inches; reddish brown (5YR 4/3) very cobbly clay loam, dark reddish brown (5YR 3/3) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and moderately plastic; many very fine and fine and common medium and coarse roots; many very fine tubular pores; many distinct clay flims on faces of peds and in pores; 25 percent cobbles and 30 percent pebbles; slightly acid (pH 6.4); clear wavy boundary. (7 to 19 inches thick)
Bt2--32 to 40 inches; reddish brown (5YR 5/3) very cobbly clay loam, reddish brown (5YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; common very fine and fine roots and few coarse roots; many very fine tubular pores and common fine tubular pores; common distinct clay films on faces of peds; 25 percent cobbles and 30 percent pebbles; neutral (pH 7.0); clear wavy boundary. (8 to 14 inches thick)
Bk--40 to 60 inches; light reddish brown (5YR 6/3) very cobbly sandy clay loam, reddish brown (5YR 5/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine tubular pores; few faint clay films on faces of peds; 25 percent cobbles and 25 percent pebbles; lime disseminated; few fine filaments of lime; few faint coatings of lime on surface of coarse fragments; slightly effervescent; slightly alkaline (pH 7.8).
TYPE LOCATION: Granite County, Montana; 1,200 feet west and 100 feet north of the SE corner of sec. 20, T. 11 N., R. 14 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 46 degrees F.
Moisture control section - between 8 and 12 inches.
Mollic epipedon thickness - 16 to 30 inches
A1 horizon - Hue: 7.5YR or 10YR
Value: 2 or 3 dry; 2 or 3 moist
Clay content: 10 to 15 percent
Rock fragments: 15 to 35 percent--0 to 10 percent cobbles; 15 to 25 percent pebbles
Reaction: pH 6.1 to 7.3
A2 horizon - Hue: 7.5YR or 10YR
Value: 3 or 4 dry; 2 or 3 moist
Texture: loam or clay loam
Clay content: 20 to 30 percent
Rock fragments: 35 to 60 percent--0 to 5 percent stones; 5 to 15 percent cobbles; 30 to 40 percent pebbles
Reaction: pH 6.1 to 7.3
Bt1 horizon - Hue: 5YR, 7.5YR, or 10YR
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Texture: clay loam or sandy clay loam
Clay content: 27 to 35 percent
Rock fragments: 35 to 70 percent--0 to 5 percent stones; 5 to 25 percent cobbles; 30 to 40 percent pebbles
Reaction: pH 6.1 to 7.3
Bt2 horizon - Hue: 5YR, 7.5YR, or 10YR
Value: 4, 5, or 6 dry; 4 or 6 moist
Chroma: 3, 4, or 6
Texture: clay loam or sandy clay loam
Clay content: 27 to 35 percent
Rock fragments: 35 to 70 percent--0 to 5 percent stones; 5 to 25 percent cobbles; 30 to 40 percent pebbles
Reaction: pH 6.6 to 7.3
Bk horizon - Hue: 5YR, 7.5YR, or 10YR
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 3, 4, or 6
Texture: sandy clay loam or clay loam
Clay content: 20 to 30 percent clay
Rock fragments: 35 to 75 percent--0 to 5 percent stones; 10 to 25 percent cobbles; 25 to 45 percent pebbles
Calcium carbonate equivalent: 1 to 5 percent
Reaction: pH 6.6 to 7.8
COMPETING SERIES:
Adellern (NM) - has transitional Bt/BC and BC/Bt horizons.
Braziel (MT) - does not have a Bk horizon.
Pastorius (CO) - does not have a Bk horizon.
Pastorpeak (AZ) - has less than 27 percent clay in the argillic horizon; has fragmental material at 60 to 80 inches.
Zillion (UT) - has a calcic horizon.
GEOGRAPHIC SETTING:
Landform - mountains.
Elevation - 3,600 to 6,400 feet.
Slope - 15 to 60 percent.
Parent material - colluvium derived from calcareous argillite.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 18 to 25 inches.
Mean annual air temperature - 38 to 42 degrees F.
Frost-free period - 70 to 90 days.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Fessler soils are used mainly for timber production, watershed, and for wildlife habitat. Potential native vegetation is mainly Douglas-fir, and ponderosa pine with an understory of common snowberry, pinegrass, mallow ninebark, elk sedge, and oregongrape.
DISTRIBUTION AND EXTENT: Fessler soils are of small extent in western Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Granite County Area, Montana, 1994.
REMARKS: Soil interpretations records: MT1480. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from 3 to 32 inches (A1, A2, and Bt1 horizons); an argillic horizon from 13 to 40 inches (Bt1 and Bt2 horizons); a horizon of secondary calcium carbonate accumulation from 40 to 60 inches (Bk horizon); a particle-size control section from 13 to 33 inches (Bt1 and Bt2 horizons). Fessler soils have a frigid temperature regime and an ustic moisture regime.