LOCATION SLAN IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Calcic Haploxeralfs
TYPICAL PEDON: Slan very gravelly loam, rangeland - on a convex south-facing slope of 50 percent at an elevation of 7,140 feet. (Colors are for dry soil unless otherwise stated.)
A--0 to 2 inches; light reddish brown (5YR 6/4) very gravelly loam, yellowish red (5YR 4/6) moist; moderate medium platy structure; soft, friable, nonsticky and nonplastic; many very fine and fine roots; many fine interstitial and common very fine tubular pores; 40 percent gravel; slightly effervescent; slightly alkaline (pH 7.8); abrupt smooth boundary. (1 to 3 inches thick)
BA--2 to 5 inches; light reddish brown (5YR 6/4) gravelly fine sandy loam, yellowish red (5YR 4/6) moist; moderate fine subangular blocky structure; soft, friable, nonsticky and nonplastic; many very fine and fine roots; common very fine and fine interstitial pores; few faint clay films on faces of peds; 20 percent gravel; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (2 to 6 inches thick)
Bt--5 to 18 inches; reddish yellow (5YR 6/6) gravelly loam, yellowish red (5YR 5/6) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine and fine roots; common very fine and fine tubular pores; common faint clay films on faces of peds; 20 percent gravel; strongly effervescent (noneffervescent in areas of clay films); moderately alkaline (pH 8.0); clear wavy boundary. (11 to 14 inches thick)
Bk--18 to 25 inches; reddish yellow (5YR 6/6) gravelly loam, red (2.5YR 5/6) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; 15 percent gravel; common 1 to 3 mm soft massis of lime; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (5 to 12 inches thick)
BC--25 to 32 inches; light reddish brown (5YR 6/4) fine sandy loam, reddish brown (5YR 5/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine roots; few very fine interstitial pores; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (4 to 10 inches thick)
Cr--32 to 60 inches; reddish brown (2.5YR 5/4) weathered Wasatch sandstone, crushing to sandy loam, red (2.5YR 4/6) moist; strongly effervescent.
TYPE LOCATION: Bear Lake County, Idaho; about 4 miles southeast of Pegram, Idaho; 800 feet north and 1250 feet west of the southeast corner of section 21, T. 15 E., R. 46 E. (Latitude 42 degrees 05 minutes 56 seconds N., Longitude 111 degrees 04 minutes 34 seconds W.)
RANGE IN CHARACTERISTICS:
Soil moisture control section - usually moist, dry for 45 consecutive days or more following the summer solstice. Xeric moisture regime.
Average annual soil temperature - 43 to 47 degrees F.
Depth to paralithic contact - 20 to 40 inches.
Depth to calcic horizon - 9 to 27 inches.
Particle-size control section
Percent clay - 18 to 30 percent
Rock fragments - 15 to 35 percent
A horizon
Hue: 7.5YR or 5YR
Value: 4 through 6 dry, 3 through 5 moist
Chroma: 3 through 6 dry or moist
Clay content: 18 to 24
Rock fragments: 35 to 50 percent gravel
Reaction: slightly or moderately alkaline
BA horizon
Hue: 5YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4 dry, 4 through 6 moist
Texture: GR-FSL, GR-L
Clay content: 10 to 22 percent
Rock fragments: 15 to 20 percent gravel
Reaction: slightly or moderately alkaline
Bt horizon
Hue: 5YR or 2.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 4 through 6 dry or moist
Texture: GR-L, GR-CL,
Clay content: 18 to 30 percent
Rock fragments: 15 to 35 percent gravel
Reaction: slightly or moderately alkaline
Bk horizon
Hue: 5YR or 2.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 4 through 6 dry or moist
Texture: GR-L, GR-CL
Clay content: 18 to 30 percent
Rock fragments: 15 to 35 percent gravel
Calcium carbonate equivalent: 15 to 30 percent
Reaction: slightly or moderately alkaline
BC horizon
Hue: 5YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 4 or 5 dry or moist
Texture: FSL, L
Clay content: 10 to 18 percent
Reaction: slightly or moderately alkaline
COMPETING SERIES:
Cokeville (T) are 40 to 60 inches to paralithic contact.
GEOGRAPHIC SETTING: Slan soils are on terrace sideslopes, hillsides, and mountainsides. These soils formed in alluvium and/or slope alluvium over residuum from sandstone and conglomerate. Slopes are 10 to 65 percent. Elevation ranges from 6,200 to 7,700 feet. The average annual precipitation is 12 to 18 inches. The average annual temperature is 37 to 45 degrees F. The frost-free season is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boundridge (T), Pontuge (T), and Warshod (T) soils. Boundridge soils have a mollic epipedon, are skeletal and have a duripan on terrace summits. Pontuge soils have a pachic epipedon and are very deep. Warshod soils have a pachic epipedon, lack an argillic horizon, are skeletal and are very deep.
DRAINAGE AND PERMEABILITY: Well drained; very rapid runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used mainly for rangeland, wildlife habitat, and watershed. Native vegetation is mountain big sagebrush, bluebunch wheatgrass, Sandberg bluegrass, and arrowleaf balsamroot.
DISTRIBUTION AND EXTENT: Southeast, Idaho. These soils are of small extent. MLRA 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Bear Lake County, Idaho, 2008.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochic epipedon - the zone from 0 to 5 inches (A and BA horizons)
Argillic horizon - the zone from 5 to 18 inches (Bt horizon)
Calcic horizon - the zone from 18 to 25 inches (Bk horizon)
Paralithic contact - the boundary at 32 inches (Cr horizon)
Particle-size control section - the zone from 5 to 18 inches (Bt horizon)