LOCATION TIBAN MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Ustic Haplocryolls
TYPICAL PEDON: Tiban stony clay loam, grassland (colors are for dry soil unless otherwise noted).
A--0 to 4 inches; brown (7.5YR 4/2) stony clay loam, dark brown (10YR 3/3) moist; very dark grayish brown (10YR 3/2) coatings moist; weak medium subangular blocky structure parting to fine granules; slightly hard, friable, nonsticky and nonplastic; many very fine roots and pores; about 35 percent subangular stones, gravel, and cobbles; neutral; clear boundary. (3 to 12 inches thick)
Bw--4 to 13 inches; grayish brown (10YR 5/2) very gravelly clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; many very fine roots and pores; about 35 percent cobbles and gravel; many clear silt and fine sand grains; slightly alkaline; clear wavy boundary. (7 to 21 inches thick)
Bk--13 to 23 inches; brown (10YR 5/3) very gravelly clay loam, brown (10YR 4/3) moist; brown (10YR 4/3) moist coatings; weak medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; few very fine roots and pores; roots matted around rocks; 45 percent gravel; common distinct lime coatings with incrustation on undersides of gravel; common fine massis of lime; strongly effervescent; moderately alkaline; clear wavy boundary. (10 to 40 inches thick)
C--23 to 60 inches; light reddish brown (2.5YR 6/4) very gravelly clay loam, red (2.5YR 4/6) moist; massive; slightly hard, friable, moderately sticky and moderately plastic; few very fine roots and pores; 50 percent gravel, cobbles, and stones of limestone, quartzite, and sandstone; fragments are all subangular and lime coated on the underside; strongly effervescent; moderately alkaline.
TYPE LOCATION: Carbon County, Montana; S 1/4 of sec. 23, T. 7 S., R. 27 E.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 35 to 45 degrees F.
Mean annual summer soil temperature - 50 to 55 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 15 inches.
Depth to Bk horizon - 13 to 32 inches.
Surface stones or boulders - 0 to 25 percent
The C horizon is below 60 inches in some pedons.
A horizon - Hue: 10YR to 2.5YR
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 1 to 3
Texture: clay loam or loam
Clay content: 18 to 35 percent
Rock fragments: 15 to 70 percent--0 to 30 percent cobbles and stones, 15 to 40 percent gravel or channers
Reaction: pH 6.1 to 7.3
Bw horizon - Hue: 10YR to 2.5YR
Value: 4 to 7 dry; 3 to 6 moist
Chroma: 1 to 4
Texture: loam, clay loam or sandy clay loam
Clay content: 18 to 35 percent
Rock fragments: 15 to 60 percent--0 to 20 percent cobbles and stones, 15 to 45 percent gravel
Calcium carbonate equivalent: 0 to 8 percent
Reaction: pH 6.1 to 8.4
Bk horizon - Hue: 10YR to 2.5YR
Value: 4 to 8 dry; 3 to 7 moist
Chroma: 1 to 4
Texture: loam, clay loam or sandy loam
Clay content: 15 to 35 percent
Rock fragments: 15 to 80 percent--0 to 20 percent cobbles, flagstones and stones, 15 to 60 percent gravel or channers
Calcium Carbonate Equivalent: 5 to 15 percent
Reaction: pH 7.4 to 8.4
C horizon - Hue: 10YR to 2.5YR
Value: 5 to 8 dry, 4 to 6 moist
Chroma: 1 to 4
Texture: loam or clay loam
Clay content: 18 to 35 percent
Rock fragments: 15 to 80 percent--0 to 20 percent cobbles, flagstones and stones, 15 to 60 percent gravel or channers
Reaction: pH 7.4 to 8.4
COMPETING SERIES:
Antrobus (CO) - does not have horizons of secondary carbonate accumulation.
Grafen (CO) - has a paralithic contact at 20 to 40 inches.
Greyback (WY) - has less than 18 percent clay in the particle-size control section.
Handran (CO) - does not have horizons of secondary carbonate accumulation.
Maurice (MT) - does not have horizons of secondary carbonate accumulation.
McCort (WY) does not have horizons of secondary carbonate accumulation.
Midelight (WY) - has a lithic contact at 40 to 60 inches.
Parachute (CO) - has a lithic contact at 20 to 40 inches.
Sebud (MT) - does not have horizons of secondary carbonate accumulation.
Supervisor (NM) - has a lithic contact at 20 to 40 inches.
Surdal (MT) - has a lithic contact at 20 to 40 inches.
Teemat (WY) - has less than 18 percent clay in the particle-size control section.
Thornburgh (CO) - does not have horizons of secondary carbonate accumulation.
Tineman (WY) - has a lithologic discontinuity at 26 to 35 inches.
Vanwirt (CO) - does not have horizons of secondary carbonate accumulation.
GEOGRAPHIC SETTING:
Landform - mountain slopes, hills, alluvial fans, stream terraces and moraines.
Elevation - 5,000 to 8,000 feet.
Slope - 0 to 75 percent.
Parent material - Colluvium, alluvium and glacial till from mixed rock sources.
Climate - long, cold winters, cool moist springs, shor summers.
Mean annual precipitation - 14to 25 inches.
Mean annual temperature - 34 to 45 degrees F.
Frost-free period - 30 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Babb, Duncom, and Tarrete soils. Babb soils are fine-loamy and have a calcic horizon. Duncom soils are shallow to a lithic contact, are loamy, and have a calcic horizon. Tarrete soils are very fine and formed in material from red shale. These soils are on similar landforms.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Tiban soils are used mainly for native grass range for summer grazing. Potential native vegetation is mainly short and mid grasses and forbs.
DISTRIBUTION AND EXTENT: Tiban soils are moderately extensive in the southern mountain areas of Montana.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Carbon County (Bridger Area), Montana, 1971.
REMARKS: Soil Interpretations Records: MT0604 and MT0605.
Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 13 inches (A, Bw horizons); a horizon of secondary carbonate accumulation from 13 to 23 inches (Bk horizon); a particle-size control section from 10 to 40 inches (Bw, Bk, C horizons). Tiban soils have a cryic temperature regime and an ustic moisture regime.