LOCATION EYERBOW MTEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive Abruptic Argicryolls
TYPICAL PEDON: Eyerbow gravelly loam, in rangeland (Colors are for dry soil unless otherwise noted.)
A--0 to 5 inches; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; few fine pores; 20 percent pebbles; slightly acid; abrupt smooth boundary.
E--5 to 8 inches; light brownish gray (10YR 6/2) gravelly loam, brown (10YR 5/3) moist; moderate medium and fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots; common very fine and fine interstitial pores; 20 percent pebbles; neutral; abrupt smooth boundary.
Bt--8 to 19 inches; brown (7.5YR 5/2) clay, brown (7.5YR 4/2) moist; strong coarse columnar structure parting to moderate medium angular blocky; extremely hard, very firm, very sticky and very plastic; few fine roots beween peds; common very fine and fine tubular pores; many distinct clay films on faces of peds; slightly alkaline; clear smooth boundary.
Bk1--19 to 22 inches; pale brown (10YR 6/3) silty clay, brown (10YR 5/3) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine roots; common fine tubular pores; strongly effervescent; common fine and medium soft masses of lime; moderately alkaline; clear smooth boundary.
Bk2--22 to 60 inches; light brown (7.5YR 6/4) silty clay loam, brown (7.5YR 5/4) moist; weak medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine roots; few fine pores; strongly effervescent; disseminated lime, few fine masses of lime; moderately alkaline.
TYPE LOCATION: Deer Lodge County, Montana; 1320 feet north and 1150 feet west of the southeast corner of section 29, T. 1N., R 14W.
RANGE IN CHARACTERISTICS:
Soil temperature - 36 to 42 degrees F.
Moisture control section - between 4 and 12 inches.
Depth to calcic horizon - 18 to 24 inches
The surface layer meets the requirements of a mollic epipedon when mixed to 7 inches.
A horizon
Hue: 10YR or 7.5YR
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Clay content: 20 to 25 percent
Content of rock fragments: 15 to 35 percent--0 to 10 percent cobbles; 15 to 25 percent pebbles
Reaction: pH 5.6 to 7.8
E horizon
Hue: 10YR or 7.5YR
Value: 6 or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Clay content: 10 to 25 percent
Content of rock fragments: 0 to 35 percent--0 to 15 percent cobbles; 0 to 20 percent pebbles
Reaction: pH 6.6 to 7.3
Bt horizon
Hue: 10YR or 7.5YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2, 3 or 4
Texture: clay or silty clay
Clay content: 45 to 60 percent
Rock fragments: 0 to 35 percent--0 to 20 percent cobbles; 0 to 15 percent pebbles
Reaction: pH 7.4 to 8.4
Bk horizons
Hue: 10YR or 7.5YR
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 2, 3 or 4
Texture: silty clay or silty clay loam
Clay content: 35 to 45 percent
Rock fragments: 0 to 35 percent--0 to 20 percent cobbles; 0 to 15 percent pebbles
Calcium carbonate equivalent: 15 to 30 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES:
Quigg (MT) - Does not have horizons of seciondary carbonate accumulation.
GEOGRAPHIC SETTING:
Landform - alluvial fans and stream terraces
Elevation - 4,000 to 6,600 feet
Slope - 2 to 50 percent
Parent material - alluvium
Climate - long, cold winters; moist springs; short, cool summers
Mean annual precipitation - 15 to 22 inches
Mean annual temperature - 34 to 40 degrees F.
Frost-free period - 30 to 70 days
DRAINAGE AND PERMEABILITY: Well-drained; slow permeability.
USE AND VEGETATION: Eyerbow soils are used mainly for rangeland, irrigated hay and pasture. Potential native vegetation is mainly western wheatgrass, Sandberg bluegrass, Idaho fescue, rough fescue and blue lupine.
DISTRIBUTION AND EXTENT: Eyerbow soils are moderately extensive in western Montana; MLRA 43.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Granite County (Philipsburg-Drummond Area), Montana, 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 7 inches (mixed) (A horizon); and albic horizon from 6 to 9 inches (E horizon); an argillic horizon which is the particle-size control section from 9 to 19 inches (Bt horizon); a calcic horizon from 19 to 60 inches (Bk horizons). Eyerbow soils have an ustic moisture regime and a cryic temperature regime.