LOCATION TEWFEL             MT
Established Series
Rev. HAL-BDD-JAL
03/1999

TEWFEL SERIES


The Tewfel series consists of moderately deep, well drained soils formed in material derived from semiconsolidated shale. These soils are on sedimentary plains and hills. Slopes are 4 to 35 percent. Mean annual precipitation is about 17 inches and mean annual temperature is about 42 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Haplustolls

TYPICAL PEDON: Tewfel clay loam, in rangeland (colors are for dry soil unless otherwise noted).

Ap--0 to 7 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; hard, very friable, moderately sticky and moderately plastic, many very fine and fine roots; many very fine and fine tubular pores; neutral (pH 6.8); clear smooth boundary. (5 to 8 inches thick)

A--7 to 12 inches; grayish brown (2.5Y 5/2) clay loam, very dark grayish brown (2.5Y 3/2) moist; weak medium subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; many very fine and fine roots; many very fine and fine tubular pores; neutral (pH 6.8); clear smooth boundary. (5 to 7 inches thick)

Bw1--12 to 21 inches; grayish brown (2.5Y 5/2) clay loam, dark grayish brown (2.5Y 4/2) moist; moderate medium subangular blocky structure; very hard, friable, moderately sticky and moderately plastic; many very fine and fine roots; common very fine tubular pores; neutral (pH 6.8); clear smooth boundary. (5 to 10 inches thick.)

2Bw2--21 to 30 inches; grayish brown (2.5Y 5/2) silty clay, dark grayish brown (2.5Y 4/2) moist; weak fine subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; few very fine tubular pores; 10 percent channers; neutral (pH 7.2); clear smooth boundary. (0 to 10 inches thick).

Cr--30 to 60 inches; semiconsolidated shale.

TYPE LOCATION: Granite County, Montana; 1,900 feet east and 1,850 feet north of the SW corner of sec. 34, T. 11 N., R. 12 W.

RANGE IN CHARACTERISTICS:

Soil temperature - 41 to 47 degrees F.

Moisture control section - between 4 and 12 inches.

Mollic epipedon thickness - 10 to 15 inches.

Depth to Cr horizon - 20 to 40 inches.

A transitional BC or C horizon is allowed.

Ap, A horizons - Value: 4 or 5 dry, 2 or 3 moist

Chroma: 1 or 2

Clay content: 27 to 35 percent

Reaction: pH 6.6 to 7.3

Bw1 horizon - Value: 5 or 6 dry, 3 or 4 moist

Chroma: 2 or 3

Clay content: 27 to 35 percent

Reaction: pH 6.6 to 7.3

2Bw2 horizon - Value: 5 or 6 dry, 4 or 5 moist

Chroma: 2 or 3

Texture: Loam, clay loam or silty clay

Clay content: 25 to 42 percent

Rock fragments: 0 to 10 percent channers

Reaction: pH 6.6 to 7.3

COMPETING SERIES:

Amor (ND) - has free carbonates in the cambic horizons; formed in residuum from moderately alkaline sandstone and siltstone.

Azaar (MT) - has horizons of secondary carbonate accumulation; has a lithic contact at depths of 20 to 40 inches.

Diagulch (UT) - has hues of 7.5YR or redder throughout.

Max (ND) - does not have a paralithic contact above a depth of 60 inches; has a calcic horizon.

Minnimaud (UT) - is strongly alkaline throughout; carbonates are disseminated throughout.

Peerless (MT) - does not have a paralithic contact; has a calcic horizon.

Quigley (MT) - has horizons of secondary carbonate accumulation; does not have a paralithic contact above a depth of 60 inches.

Roundup (MT) - has horizons of secondary carbonate accumulation; formed in interbedded siltstone and sandstone.

Shambo (ND) - does not have a paralithic contact above a depth of 60 inches; has horizons of secondary carbonate accumulation.

Tansem (ND) - has a calcic horizon; does not have a paralithic contact.

Twin Creek (MT) - has horizons of secondary carbonate accumulation; does not have a paralithic contact above a depth of 60 inches.

GEOGRAPHIC SETTING:

Landform - sedimentary plains and hills.

Elevation - 3,600 to 6,000 feet.

Slope- 4 to 35 percent.

Parent material - material derived from semiconsolidated shale.

Climate - long, cold winters; moist springs; warm summers.

Mean annual precipitation - 15 to 19 inches.

Mean annual temperature - 39 to 45 degrees F.

Frost-free period - 70 to 90 days.

DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.

USE AND VEGETATION: Tewfel soils are used mainly for rangeland. Native vegetation is western wheatgrass, bluebunch wheatgrass, Idaho fescue, antelope bitterbrush, lupine, woods rose, prairie junegrass, and rough fescue.

DISTRIBUTION AND EXTENT: Tewfel soils are of small extent in southwestern Montana.

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

SERIES ESTABLISHED: Granite County, Montana, 1997.

REMARKS: Soil interpretation record: MT1408. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 12 inches (Ap, A horizons); a cambic horizon from 12 to 21 inches (Bw1, Bw2 horizons); a paralithic contact at a depth of 30 inches; a particle-size control section from 10 to 30 inches (A, Bw1, Bw2 horizons). Tewfel soils have a frigid temperature regime and an ustic moisture regime.


National Cooperative Soil Survey
U.S.A.