LOCATION TARRETE MTEstablished Series
TAXONOMIC CLASS: Very-fine, mixed, superactive Typic Haplocryolls
TYPICAL PEDON: Tarrete clay, in grassland (colors are for dry soil unless otherwise noted).
A1--0 to 2 inches; dark reddish gray (5YR 4/2) clay, dark reddish brown (5YR 3/3) moist; weak platy structure parting to moderate, coarse, granular; slightly hard, friable, moderately sticky and moderately plastic; many very fine roots; neutral (pH 6.6); clear boundary. (2 to 4 inches thick)
A2--2 to 9 inches; reddish brown (5YR 4/3) clay, dark reddish brown (5YR 3/3) moist; moderate coarse, medium, and fine subangular blocky structure; extremely hard, firm, moderately sticky and moderately plastic; many very fine roots and tubular pores; neutral (pH 6.6); clear, wavy boundary. (5 to 11 inches thick)
Bw--9 to 18 inches; reddish brown (2.5YR 4/4) clay, red (2.5YR 4/6) moist; strong coarse, medium, and fine subangular blocky structure; extremely hard, firm, moderately sticky and moderately plastic; many very fine roots and very fine tubular pores; 10 percent limestone pebbles; neutral (pH 6.6); gradual boundary. (8 to 10 inches thick)
Bk1--18 to 28 inches; dark red (10R 3/6) clay, dark red (10R 3/6) moist; strong, medium, and fine subangular blocky structure; extremely hard, firm, moderately sticky and moderately plastic; few very fine roots; common fine tubular pores; common fine masses of lime; strongly effervescent; moderately alkaline (pH 8.4); gradual boundary. (10 to 15 inches thick)
Bk2--28 to 45 inches; dark red (10R 3/6) dry or moist; clay relict redox concentrations brownish yellow (10YR 6/6); massive; extremely hard, firm, moderately sticky and moderately plastic; 2 percent argillite and quartzite pebbles; common fine and medium masses and threads of lime; strongly effervescent; moderately alkaline (pH 8.4); gradual boundary. (0 to 18 inches thick)
Bk3--45 to 54 inches; dusky red (10R 3/4) dry or moist; clay relict redox concentrations with pale brown (10YR 6/3); massive; extremely hard, firm, moderately sticky and moderately plastic; 2 percent argillite and quartzite pebbles; few fine masses of lime; strongly effervescent; moderately alkaline (pH 8.4); gradual boundary. (15 to 45 inches thick)
C--54 to 60 inches; dusky red (10R 3/3) dry or moist; clay relict redox concentrations light brownish gray (10YR 6/2); massive; extremely hard, firm, moderately sticky and moderately plastic; 2 percent argillite and quartzite pebbles; strongly effervescent; disseminated lime; moderately alkaline (pH 8.4).
TYPE LOCATION: Carbon County, Montana; 10,000 feet east and 5,280 feet north of Ice Cave elevation marker 8786, T. 8 S., R. 27 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 40 to 45 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 15 inches.
Depth to Bk horizon - 15 to 25 inches.
A1 horizon - Chroma: 2 or 3
Texture: clay, silty clay, silty clay loam, or loam
Clay content: 20 to 60 percent slopes
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 6.6 to 7.8
A2 horizon - Chroma: 2 or 3
Clay content: 60 to 80 percent
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 6.6 to 7.8
Bw horizon - Hue: 2.5YR, 5YR, 10R
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 4 or 6
Clay content: 60 to 80 percent
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 6.6 to 7.8
Bk horizons - Hue: 2.5YR, 5YR, 10R
Value: 3, 4, or 5, dry or moist
Chroma: 3, 4, or 6
Clay content: 60 to 80 percent
Rock fragments: 0 to 15 percent
Reaction: pH 7.4 to 8.4
C horizon - Hue: 5YR or 10R
Value: 3 or 4, dry or moist
Chroma: 3 or 4
Clay content: 60 to 80 percent
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 7.4 to 8.4
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - hills; mountains.
Elevation - 6,000 to 9,000 feet.
Slope - 8 to 75 percent.
Parent material - colluvium from red clay shales of the Amsden formation.
Climate - long, cold winters; moist springs; cool summers.
Mean annual precipitation - 15 to 30 inches.
Mean annual air temperature - 38 to 43 degrees F.
Frost-free period - 50 to 70 days.
DRAINAGE AND PERMEABILITY: Well drained; very slow permeability.
USE AND VEGETATION: Tarrete soils are used mainly for rangeland. Potential native vegetation is Bluebunch wheatgrass, western wheatgrass, Idaho fescue, green needlegrass, cinquefoil, and other forbs and shrubs.
DISTRIBUTION AND EXTENT: Tarrete soils are inextensive in south-central Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Big Horn County, Montana, 1970.
REMARKS: Soil interpretations record: MT0435. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 9 inches (A1, A2 horizons); a cambic horizon from 9 to 18 inches (Bw horizon); horizons of carbonate accumulation from 18 to 54 inches (Bk1, Bk2, Bk3 horizons); a particle-size control section from 10 to 40 inches (Bw, Bk1, Bk2 horizons). Tarrete soils have a cryic temperature regime and a udic moisture regime.