LOCATION INABNIT                 MT

Established Series
Rev: PEM-KTS-RJS
04/2011

INABNIT SERIES

The Inabnit series consists of shallow, well drained soils that formed in slope alluvium or colluvium over residuum derived from sedimentary bedrock. These soils are on hills, mountain slopes and escarpments. Slopes are 4 to 45 percent. Mean annual precipitation is about 17 inches, and mean annual air temperature is about 38 degrees F.

TAXONOMIC CLASS: Loamy, mixed, superactive, shallow Ustic Haplocryalfs

TYPICAL PEDON: Inabnit very cobbly loam, stony, in rangeland (colors are for dry soil unless otherwise noted).

A--0 to 3 inches; grayish brown (10YR 5/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium subangular blocky structure parting to weak very fine and fine granular; soft, very friable, slightly sticky and slightly plastic; many very fine and few fine roots; many very fine and fine dendritic tubular pores; 30 percent gravel, 20 percent cobbles; neutral (pH 7.1); clear wavy boundary. (2 to 4 inches thick)

Bt--3 to 15 inches; light yellowish brown (10YR 6/4) very paragravelly silty clay loam, yellowish brown (10YR 5/4) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; many very fine and few fine roots; common very fine and few fine dendritic tubular pores; common faint patchy clay films on faces of peds and many faint discontinuous clay films on paragravel; 50 percent semi-consolidated siltite paragravel; neutral (pH 7.1); clear wavy boundary. (6 to 15 inches thick)

Cr--15 to 60 inches; light gray (2.5Y 7/1) semi-consolidated siltite beds that crush to silt loam, light yellowish brown (2.5Y 6/3) moist; neutral (pH 7.3).

TYPE LOCATION: Beaverhead County, Montana; approximately 600 feet south and 100 feet west of the NE corner of sec. 8, T. 6S., R. 14W. Butch Hill topographic quadrangle, UTM 12T, 316852e, 5022661n, NAD 83.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 35 to 40 degrees F. Cryic temperature regime.
Depth to top of argillic horizon - 2 to 4 inches
Depth to paralithic contact - 10 to 20 inches

Note: Some pedons may have a thin Bk or C horizon above the Cr horizon.

A horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 or 6 dry; 3 to 5 moist
Chroma: 1 to 3; dry or moist
Texture: loam or silt loam
Clay content: 15 to 25 percent
Rock fragments: 15 to 60 percent--15 to 35 percent gravel, 0 to 25 percent cobbles
Reaction: pH 6.6 to 7.6

Bt horizons
Hue: 10YR, 2.5Y or 5Y; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4; dry or moist
Texture: loam, clay loam or silty clay loam
Clay content: 25 to 35 percent
Rock fragments: 0 to 35 percent--0 to 30 percent gravel, 0 to 5 percent cobbles
Pararock fragments: 35 to 60 percent paragravel
Reaction: pH 6.6 to 7.6

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING:
Landform - hills, mountain slopes and escarpments
Elevation - 5,900 to 7,650 feet
Slope - 4 to 45 percent
Parent material - slope alluvium or colluvium over residuum derived from sedimentary bedrock
Climate - long, cold winters; cool, moist springs; short, cool summers
Mean annual precipitation - 14 to 24 inches
Mean annual air temperature - 34 to 39 degrees F.
Frost-free period - 30 to 70 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hooligan and Monaberg soils. Hooligan soils are 20 to 40 inches to bedrock. Monaberg soils have a mollic epipedon. These soils are in swales and on footslopes of hills.

DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.

USE AND VEGETATION: Inabnit soils are primarily used for rangeland, woodland, and wildlife habitat. The potential native vegetation is mainly Idaho fescue, forbs and shrubs.

DISTRIBUTION AND EXTENT: Inabnit soils are of small extent in southwestern Montana. MLRAs - 43B, 44B.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.

SERIES ESTABLISHED: Beaverhead County, Montana, Big Hole Valley Area, 2005.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 3 inches (A horizon)
Argillic horizon - from 3 to 15 inches (Bt horizon)
Paralithic contact - at 15 inches (Cr horizon)
Particle-size control section - from 3 to 15 inches (Bt horizon)

Inabnit soils have a cryic temperature regime and an ustic moisture regime.

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National Cooperative Soil Survey
U.S.A.