LOCATION GILISPIE MT+ID OR WYEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive Lithic Argicryolls
TYPICAL PEDON: Gilispie gravelly loam, in rangeland (colors are for dry soil unless otherwise noted).
A1--0 to 3 inches; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak medium platy structure parting to moderate fine granular; soft, very friable, slightly sticky and slightly plastic; many very fine roots and tubular pores; few skeletons on pebbles; 25 percent pebbles; neutral (pH 7.0); clear smooth boundary.
A2--3 to 6 inches; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure parting to strong fine granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots, many fine tubular pores; common skeletons on faces of peds; 20 percent pebbles; neutral (pH 7.2); clear smooth boundary. (combined A horizon is 5 to 8 inches thick)
Bt--6 to 14 inches; pale brown (10YR 6/3) gravelly clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium angular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine roots and tubular pores; common faint clay films on faces of peds; 25 percent pebbles; slightly alkaline (pH 7.6); gradual smooth boundary. (6 to 12 inches thick)
BC--14 to 18 inches; pale brown (10YR 6/3) extremely cobbly clay loam, brown (10YR 4/3) moist; moderate fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few very fine roots, few fine pores; 75 percent cobbles; neutral (pH 7.2); clear smooth boundary. (0 to 8 inches thick)
R--18 inches; hard andesite.
TYPE LOCATION: Granite County, Montana; 1,650 feet west and 150 feet north of SE corner of sec. 5, T. 9 N., R. 13 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F.
Mollic epipedon thickness - 7 to 10 inches.
Depth to bedrock - 10 to 20 inches.
A1 horizon - Hue: 7.5YR, 10YR, or 2.5Y
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 1 or 2
Clay content: 15 to 27 percent
Rock fragments: 15 to 35 percent--15 to 35 percent pebbles, 20 to 35 percent cobbles or stones
Reaction: pH 6.6 to 7.8
A2 horizon - Hue: 7.5YR, 10YR, or 2.5Y
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 1 or 2
Clay content: 20 to 25 percent
Rock fragments: 15 to 35 percent--15 to 35 percent pebbles, 20 to 35 percent cobbles or stones
Reaction: pH 6.6 to 7.8
Bt horizon - Hue: 7.5YR, 10YR, or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2, 3, or 4
Texture: loam or clay loam
Clay content: 25 to 35 percent
Rock fragments: 15 to 35 percent--0 to 10 percent cobbles; 15 to 35 percent pebbles
Reaction: pH 6.6 to 7.8
BC horizon - Hue: 7.5YR, 10YR, or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2, 3, or 4
Texture: loam or clay loam
Clay content: 20 to 30 percent
Rock fragments: 60 to 80 percent--65 to 75 percent cobbles; 0 to 10 percent pebbles
Reaction: pH 6.6 to 7.3
COMPETING SERIES:
Carbol (CO) - has more than 35 percent fine or coarser sand in the Bt horizon.
Chittum (WY) - has hue of 5YR or redder in the Bt horizon.
Katseanes (ID) - has less than 15 percent coarse fragments in the particle-size control section.
Mahogee (NV) - has a xeric moisture regime.
GEOGRAPHIC SETTING:
Landform - hills and mountains.
Elevation - 4,000 to 6,500 feet.
Slope - 0 to 60 percent.
Parent material - colluvium or residuum derived from andesite, ryolite, or basalt.
Climate - long, cold winters; moist springs; and cool summers.
Mean annual precipitation - 15 to 22 inches.
Mean annual temperature - 40 to 45 degrees F.
Frost-free period - 30 to 70 days.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Gilispie soils are used mainly as rangeland. Potential native vegetation is mainly bluebunch wheatgrass, Sandberg bluegrass, big sagebrush, and prairie junegrass.
DISTRIBUTION AND EXTENT: Gilispie soils are of small extent in western Montana, eastern Idaho, Wyoming and Oregon.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Granite County, Montana, 1972.
REMARKS: Soil Interpretation Records: MT0571 and MT0660.
Diagnostic horizons and features recognized in this pedon are: a mollic epipedon when mixed to 7 inches (A1 and A2 horizons); an argillic horizon which is the particle-size control section from 6 to 14 inches (Bt horizon); and a lithic contact at 18 inches (R horizon). Gilispie soils have a cryic temperature regime and an ustic moisture regime.