LOCATION WIDEN              MT
Established Series
Rev. JAL
03/2002

WIDEN SERIES


The Widen series consists of moderately deep, well drained soils that formed in residuum derived from interbedded weakly consolidated shale and siltstone. These soils are on mountains. Slopes are 2 to 60 percent. Mean annual precipitation is about 19 inches, and mean annual temperature is about 41 degrees F.

TAXONOMIC CLASS: Fine, smectitic, frigid Typic Haplustepts

TYPICAL PEDON: Widen silty clay loam, forested (colors are for dry soil unless otherwise noted).

Oi-0 to 1 inch; forest litter of undecomposed and decomposed needles, twigs, cones, and leaves. (1 to 3 inches thick)

A--1 to 2 inches; dark gray (10YR 4/1) silt loam, black (10YR 2/1) moist; moderate fine granular structure; soft, friable, slightly sticky and nonplastic; many fine and very fine roots; many very fine pores; slightly acid (pH 6.2); clear wavy boundary. (1 to 4 inches thick)

E--2 to 5 inches; pinkish gray (7.5YR 6/2) silty clay loam, brown (7.5YR 4/2) moist; weak medium and thin platy structure parting to strong fine granular; hard, friable, moderately sticky and moderately plastic; many coarse, medium, and fine roots; many very fine pores; slightly acid (pH 6.2); clear wavy boundary. (0 to 4 inches thick)

Bw--5 to 13 inches; brown (10YR 5/3) silty clay, brown (10YR 4/3) moist; weak medium prismatic structure parting to strong fine subangular blocky; very hard, firm, very sticky and very plastic; many coarse, medium, and fine roots; common medium and fine pores and many very fine pores; organic stains on faces of peds; slightly acid (pH 6.4); clear wavy boundary. (8 to 18 inches thick)

Bk--13 to 37 inches; pale yellow (2.5Y 7/4) silty clay, light olive brown (2.5Y 5/4) moist; moderate medium subangular blocky structure; very hard, firm, very sticky and very plastic; common coarse, medium, fine, and many very fine roots; many fine and very fine pores; common fine threads of lime; strongly effervescent; slightly alkaline (pH 7.8); gradual wavy boundary. (10 to 24 inches thick)

Cr--37 to 60 inches; pale yellow (2.5Y 8/4) interbedded weakly consolidated shale and siltstone, olive yellow (2.5Y 6/6) moist; very hard, firm, moderately sticky and moderately plastic; strongly effervescent; slightly alkaline (pH 7.8).

TYPE LOCATION: Fergus County, Montana; 800 feet west and 1,200 feet south of the NE corner of sec. 2, T. 16 N., R. 19 E.

RANGE IN CHARACTERISTICS:

Soil temperature - 41 to 47 degrees F.
Moisture control section - between 4 and 12 inches
Depth to Cr horizon - 20 to 40 inches.
Depth to Bk horizon - 10 to 20 inches.

A horizon - Hue: 10YR or 2.5Y
Value: 3, 4, or 5 dry; 2, 3 or 4 moist
Chroma: 1, 2 or 3
Texture: silt loam or loam
Clay content: 15 to 27 percent
Rock fragments: 0 to 10 percent--0 to 5 percent cobbles; 0 to 5 percent pebbles
Reaction: pH 6.1 to 7.8

E horizon - Hue: 10YR, 7.5YR or 5YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: silty clay loam or clay loam
Clay content: 27 to 40 percent
Rock fragments: 0 to 10 percent--0 to 5 percent cobbles; 0 to 5 percent pebbles
Reaction: pH 6.1 to 7.8

Bw horizon - Hue: 7.5YR, 10YR, 2.5Y or 5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: clay loam, silty clay loam, silty clay, or clay
Clay content: 35 to 50 percent
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles; 0 to 10 percent pebbles
Reaction: pH 6.1 to 8.4

Bk horizon - Hue: 5YR through 5Y
Value: 6, 7, or 8 dry; 4, 5, 6, or 7 moist
Chroma: 2, 3, or 4
Texture: clay loam, silty clay loam, silty clay or clay
Clay content: 35 to 50 percent
Rock fragments: 0 to 15 percent--0 to 5 percent angular cobbles; 0 to 10 percent pebbles
Reaction: pH 7.4 to 9.0

Cr horizon - semiconsolidated shale or interbedded shale and siltstone.

COMPETING SERIES:

Sagedale (MT) - does not have a paralithic contact.

GEOGRAPHIC SETTING:

Landform - mountains.
Elevation - 2,500 to 5,000 feet.
Slope - 2 to 60 percent.
Parent material - residuum derived from interbedded semiconsolidated shale and sandstone.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 15 to 24 inches.
Mean annual temperature - 39 to 45 degrees F.
Frost-free period - 80 to 135 days.

DRAINAGE AND PERMEABILITY: Well drained; slow permeability.

USE AND VEGETATION: Widen soils are used mainly for woodland and rangeland. Potential native vegetation is mainly ponderosa pine and Douglas-fir with an understory of Columbia needlegrass, common snowberry, creeping Oregon-grape, bluebunch wheatgrass, blue wildrye, woods rose, common juniper, Idaho fescue, and heartleaf arnica.

DISTRIBUTION AND EXTENT: Widen soils are inextensive in central Montana.

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

SERIES ESTABLISHED: Fergus County, Montana, 1979.

REMARKS: Soil Interpretations Record: MT0348. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the soil surface to 5 inches (A, E horizons); a cambic horizon from 5 to 13 inches (Bw horizon); a horizon of secondary carbonate accumulation from 13 to 37 inches (Bk horizon); a paralithic contact at 37 inches (Cr horizon); a particle-size control section from 11 to 36 inches (Bw, Bk horizons). Widen soils have a frigid temperature regime and an ustic moisture regime.


National Cooperative Soil Survey
U.S.A.