LOCATION REDLOCK            MT 
Established Series
TJW-GLS-JAL
11/1999

REDLOCK SERIES


The Redlock series consists of very deep, well drained soils that formed in volcanic ash over glaciolacustrine deposits. These soils are on lake plains and terraces in valleys. Slopes are 0 to 35 percent. Mean annual precipitation is about 30 inches, and mean annual temperature is about 44 degrees F.

TAXONOMIC CLASS: Coarse-loamy over clayey, mixed, active, frigid Andic Hapludalfs

TYPICAL PEDON: Redlock ashy silt loam, forested (colors are for moist soil unless otherwise noted).

Oi--0 to 2 inches; undecomposed and slightly decomposed forest litter. (1 to 2 inches thick)

A--2 to 3 inches; dark grayish brown (10YR 4/2) ashy silt loam, grayish brown (10YR 5/2) dry; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium and common coarse roots; moderately acid (pH 6.0); clear wavy boundary. (0 to 3 inches thick)

Bw--3 to 14 inches; dark yellowish brown (10YR 4/4) ashy silt loam, light yellowish brown (10YR 6/4) dry; weak, medium subangular blocky structure parting to moderate fine granular; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium and common coarse roots; slightly acid (pH 6.4); clear wavy boundary. (7 to 11 inches thick)

2E--14 to 19 inches; brown (10YR 5/3) very fine sandy loam, very pale brown (10YR 7/3) dry; weak fine granular structure; slightly hard, very friable, nonsticky and nonplastic; many fine and medium and common coarse roots; common fine and medium yellowish brown (10YR 5/6) prominent iron stains on faces of peds; slightly acid (pH 6.4); gradual wavy boundary. (5 to 20 inches thick)

2E/Bt--19 to 24 inches; E part (80 percent) is grayish brown (10YR 5/2) fine sandy loam, light gray (10YR 7/2) dry, Bt part (20 percent) is brown (7.5YR 5/2) loam, pinkish gray (7.5YR 6/2) dry; moderate medium subangular blocky structure; hard, firm, slightly sticky and nonplastic; many fine and medium and common coarse roots; common fine and medium yellowish brown (10YR 5/6) prominent iron stains on faces of peds; few distinct clay films on faces of peds; moderately acid (pH 6.0); clear wavy boundary. (0 to 7 inches thick)

2Bt/E--24 to 30 inches; Bt part (60 percent) is brown (7.5YR 5/2) loam, pinkish gray (7.5YR 6/2) dry, E part (40 percent) is grayish brown (10YR 5/2) fine sandy loam, light gray (10YR 7/2) dry; moderate medium subangular blocky structure; hard, firm, slightly sticky and nonplastic; few fine and common medium and coarse roots; common fine and medium yellowish brown (10YR 5/6) prominent iron stains on faces of peds; few distinct clay films on faces of peds; slightly acid (pH 6.2); clear wavy boundary. (6 to 8 inches thick)

3E & Bt--30 to 40 inches; E (60 percent) is light brownish gray (10YR 6/2) loamy very fine sand, light gray (10YR 7/2) dry; weak fine granular structure; loose; nonsticky and nonplastic; few fine and common medium and coarse roots; common fine and medium yellowish brown (10YR 5/6) prominent iron stains on faces of peds; moderately acid (pH 6.0); Bt (40 percent) is brown (7.5YR 5/4) 1/2 inch to 2 inch thick very fine sandy loam lamellae, light brown (7.5YR 6/4) dry; moderate medium platy structure; slightly hard, friable, slightly sticky and nonplastic; few fine and common medium and coarse roots; common fine and medium yellowish brown (10YR 5/6) prominent iron stains on faces of peds; common distinct clay films on faces of peds; moderately acid (pH 6.0); clear wavy boundary. (0 to 10 inches thick)

4Bt--40 to 46 inches; brown (7.5YR 5/4) clay, pinkish gray (7.5YR 7/2) dry; moderate coarse subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few medium roots; few fine and medium yellowish brown (10YR 5/6) prominent iron stains on faces of peds; many distinct clay films on faces of peds; slightly acid (pH 6.2); gradual wavy boundary. (6 to 8 inches thick)

5E & Bt--46 to 56 inches; E (60 percent) is light brownish gray (10YR 6/2) loamy very fine sand, light gray (10YR 7/2) dry; weak fine granular structure; loose; nonsticky and nonplastic; few medium roots; common fine and medium yellowish brown (10YR 5/6) prominent iron stains on faces of peds; moderately acid (pH 6.0); Bt (40 percent) is brown (7.5YR 5/4) 1 inch to 3 inch thick very fine sandy loam lamellae, light brown (7.5YR 6/4) dry; moderate medium platy structure; slightly hard, friable, slightly sticky and nonplastic; few medium roots; common fine and medium yellowish brown (10YR 5/6) prominent iron stains on faces of peds; common distinct clay films on faces of peds; moderately acid (pH 5.8); clear wavy boundary. (10 to 15 inches thick)

6Bt--56 to 60 inches; brown (7.5YR 5/4) clay, pinkish gray (7.5YR 7/2) dry; moderate coarse subangular blocky structure; hard, firm, moderately sticky and moderately plastic; many distinct clay films on faces of peds; moderately acid (pH 5.8).

TYPE LOCATION: Sanders County, Montana; 2550 feet west and 50 feet north of the southeast corner of section 29, T. 24N., R. 31W.

RANGE IN CHARACTERISTICS:

Soil temperature - 44 to 47 degrees F.
Moisture control section - between 8 and 24 inches.

A horizon - Value: 4, 5, or 6 dry, 3, 4, or 5 moist
Clay content: 5 to 15 percent
Bulk density: 0.85 to 1.0 g/cm3
Acid oxalate extractable Al + 1/2 Fe: 1.0 to 2.0 percent
Reaction: 5.1 to 6.5

Bw horizon - Value: 5 or 6 dry, 4 or 5 moist
Clay content: 5 to 15 percent
Bulk density: 0.85 to 1.0 g/cm3
Acid oxalate extractable Al + 1/2 Fe: 1.0 to 2.0 percent
Reaction: 5.1 to 6.5

2E horizon - Value: 5, 6, or 7 dry, 4, 5, or 6 moist
Clay content: 5 to 15 percent
Reaction: 5.1 to 6.5

2E/Bt horizon - Hue: E part 10YR, Bt part 7.5YR or 10YR
Value: E part 5, 6, or 7, Bt part 4, 5, or 6 dry; E part 4, 5, or 6, Bt part 3, 4, or 5 moist
Clay content: E part 8 to 12 percent; Bt part 12 to 18 percent
Reaction: 5.1 to 6.5

2Bt/E horizon - Hue: Bt part 7.5YR or 10YR, E part 10YR
Value: Bt part 4, 5, or 6, E part 5, 6, or 7 dry; Bt part 3, 4, or 5, E part 4, 5, or 6 moist
Clay content: Bt part 12 to 18 percent; E part 8 to 12 percent
Reaction: 5.1 to 6.5

3E & Bt horizon - Hue: E part 10YR, Bt part 7.5YR or 10YR
Value: E is 5, 6, or 7, Bt is 5, 6, or 7 dry; E is 4, 5, or 6, Bt is 4, 5, or 6 moist
Clay content: E is 8 to 12 percent, Bt is 12 to 18 percent
Reaction: 5.6 to 6.5

4Bt horizon - Hue: 7.5YR or 10YR
Value: 5, 6, or 7 dry, 4, 5, or 6 moist
Clay content: 40 to 60 percent
Reaction: 5.6 to 6.5

5E & Bt horizon - Hue: E part 10YR, Bt part 7.5YR or 10YR
Value: E is 5, 6, or 7, Bt is 5, 6, or 7 dry; E is 4, 5, or 6, Bt is 4, 5, or 6 moist
Clay content: E is 8 to 12 percent, Bt is 12 to 18 percent
Reaction: 5.6 to 6.5

6Bt horizon - Hue: 7.5YR or 10YR
Value: 5, 6, or 7 dry, 4, 5, or 6 moist
Chroma: 2, 4 or 6
Clay content: 40 to 60 percent
Reaction: 5.6 to 6.5

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING:

Landform - lake plains and terraces in valleys.
Elevation - 2200 to 2800 feet.
Slope - 0 to 35 percent.
Parent material - volcanic ash over glaciolacustrine deposits.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 28 to 34 inches.
Mean annual temperaure - is 42 to 45 degrees F.
Frost-free period - 90 to 105 days.

DRAINAGE AND PERMEABILITY: Well drained, moderate permeability to the 4Bt horizon, slow below.

USE AND VEGETATION: Redlock soils are used mainly for woodland, understory grazing, and wildlife habitat. Potential native vegetation is mainly Douglas fir, western larch, lodgepole pine, grand fir, western white pine, western red cedar, and western hemlock. Understory vegetation is mainly common snowberry, pinegrass, oceanspray, twinflower, queencup beadlily, sweetscented bedstraw, wild sarsaparilla, and other forbs and shrubs.

DISTRIBUTION AND EXTENT: Redlock soils are of small extent in the valleys of northwestern Montana.

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

SERIES ESTABLISHED: Sanders County, Montana 1997.

REMARKS: Soil Interpretation Record: MT1380. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the mineral soil surface to 7 inches mixed (A, Bw horizons); an ash influenced surface layer from 2 to 14 inches (A, Bw horizons); an albic horizon from 14 to 19 inches (2E horizon); a particle size control section from 24 to 44 inches (2Bt/E, 3E and Bt, 4Bt horizons). Redlock soils have a udic moisture regime and a frigid temperature regime.

Additional Data: NSSL S92MT-089-005


National Cooperative Soil Survey
U.S.A.