LOCATION SHOOFLIN MTEstablished Series
TAXONOMIC CLASS: Very-fine, smectitic, frigid Vertic Paleustalfs
TYPICAL PEDON: Shooflin silt loam, in coniferous forest. (Colors are for dry soil unless otherwise noted.)
0i--0 to 2 inches; undecomposed and slightly decomposed forest litter.
E1--2 to 6 inches; light gray (10YR 7/2) silt loam, dark grayish brown (10YR 4/2) moist; moderate thin platy structure; slightly hard, very friable, nonsticky, slightly plastic; many very fine, fine, and medium roots; many very fine pores; moderately acid (pH 5.6); clear wavy boundary.
E2--6 to 14 inches; light gray (10YR 7/2) silt loam, grayish brown (10YR 5/2) moist; moderate medium platy structure; slightly hard, very friable, nonsticky, slightly plastic; many very fine, fine, medium, and coarse roots; many very fine pores; moderately acid (pH 6.0); abrupt smooth boundary. (Combined thickness of the E horizons is 4 to 15 inches.)
Bt1--14 to 21 inches; light brownish gray (2.5Y 6/2) clay, olive brown (2.5Y 4/4) moist; strong medium prismatic structure; extremely hard, extremely firm, very sticky, very plastic; common fine and medium roots; few medium pores; thin continuous clay films on faces of peds; moderately acid (pH 5.7); clear smooth boundary. (3 to 10 inches thick)
Bt2--21 to 27 inches; light brownish gray (2.5Y 6/2) clay, light olive brown (2.5Y 5/4) moist; strong medium prismatic structure; extremely hard, extremely firm, very sticky, very plastic; common fine and medium roots; few medium pores; thin continuous clay films on faces of peds; moderately acid (pH 5.8); clear smooth boundary. (5 to 15 inches thick)
Bt3--27 to 42 inches; pale yellow (2.5Y 7/4) clay, light yellowish brown (2.5Y 6/4) moist; moderate medium angular blocky structure; hard, very firm, very sticky, very plastic, common fine and medium roots; common very fine pores; thin continuous clay films on faces of peds; strongly acid (pH 5.5); clear smooth boundary. (8 to 18 inches thick)
Bt4--42 to 53 inches; yellow (2.5Y 7/6) clay, light yellowish brown (2.5Y 6/4) moist; moderate fine angular blocky structure; hard, very firm, moderately sticky, very plastic; few fine roots; common very fine pores; thin continuous clay films on faces of peds; strongly acid (pH 5.5); clear smooth boundary. (7 to 12 inches thick)
Cr--53 to 60 inches; pale yellow (2.5Y 7/4) fractured semiconsolidated sedimentary mudstone beds that crush to silt loam, light gray (2.5Y 7/2) moist.
TYPE LOCATION: Missoula County, Montana; 1,300 feet north and 500 feet west of the SE corner of sec. 26, T. 14 N., R. 17 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 46 degrees F.
Moisture control section - approximately between the depths of 4 and 12 inches
Control section - 60 to 80 percent clay
Depth to paralithic contact: 40 to 60 inches
E horizon - Hue: 10YR or 7.5YR
Value: 6 or 7 dry; 3 through 6 moist
Chroma: 1 through 3
Clay content: 10 to 20 percent
Rock fragments: 0 to 15 percent--0 to 10 percent cobbles; 0 to 5 percent pebbles
Reaction: pH 5.1 to 6.0
Bt horizons - Hue: 2.5Y, 10YR, or 7.5YR
Value: 4 through 7 dry; 4 through 6 moist
Chroma: 2 through 6
Clay content: 60 to 80 percent
Rock fragments: 0 to 10 percent--0 to 5 percent cobbles; 0 to 5 percent pebbles
Reaction: pH 4.5 to 6.0
Cr horizon - (This horizon may be deeper than 60 inches in some pedons.) Hue: 2.5Y or 10YR
Value: 6 or 7 dry; 5 through 7 moist
Chroma: 2 through 5
Sedimentary beds: semiconsolidated or weakly consolidated mudstone or siltstone
Reaction: pH 4.5 to 6.0
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Shooflin soils are on terraces and foothills in intermountain valleys. Elevations are 3,500 to 4,500 feet. Slopes are 4 to 15 percent. These soils formed in material derived from Tertiary sediment. The climate is characterized by long, cold winters and moist springs. Mean annual precipitation is 16 to 22 inches, much of which falls as snow and as spring rain. Mean annual temperature is 40 to 44 degrees F. The frost-free period is 60 to 90 days.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: Shooflin soils are used for timber production and watersheds and as wildlife habitat. The native vegetation is ponderosa pine, western larch, and Douglas-fir with an understory of pinegrass, serviceberry, snowberry, spiraea, Oregongrape, dwarf huckleberry, and kinnikinnick.
DISTRIBUTION AND EXTENT: Shooflin soils are of small extent in western Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Missoula County, Montana, 1985.
REMARKS: Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the soil surface to 14 inches which is also the albic horizon (E1, E2 horizons); an argillic horizon from 14 to 53 inches (Bt1, Bt2, Bt3, Bt4 horizons); a particle-size control section from 14 to 34 inches (Bt1, Bt2, Bt3 horizons) which is the upper 20 inches of the argillic horizon. Shooflin soils have a frigid temperature regime and an ustic moisture regime.
ADDITIONAL DATA: Laboratory S70MONT-63-9 and S70MONT-63-1.