LOCATION BOUNDRIDGE IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, shallow Typic Duricryolls
TYPICAL PEDON: Boundridge very gravelly loam, rangeland-on a 8 percent slope on a northwesterly aspect at an elevation of 7,410 feet. (Colors are for dry soil unless otherwise noted. When described in October 1983, the profile was slightly moist throughout.)
A--0 to 2 inches; grayish brown (10YR 5/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine irregular pores; 35 percent gravels and 5 percent cobbles; slightly alkaline (pH 7.4); abrupt smooth boundary. (2 to 4 inches thick)
AB--2 to 7 inches; brown (10YR 5/3) very gravelly silt loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine, fine and medium roots; many very fine irregular, and few tubular pores; 35 percent gravels and 10 percent cobbles; slightly alkaline (pH 7.6); abrupt wavy boundary. (0 to 6 inches thick)
Bw--7 to 14 inches; brown (10YR 5/3) very gravelly loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many very fine, fine and medium roots; common very fine tubular and irregular pores; 35 percent gravels and 15 percent cobbles; slightly effervescent (4 percent calcium carbonate equivalent); slightly alkaline (pH 7.8); abrupt wavy boundary. (3 to 12 inches thick)
Bkqm--14 to 21 inches; very pale brown (10YR 8/2) duripan, very pale brown (10YR 7/3) moist; strong very coarse platy structure; extremely hard, extremely firm, nonsticky and nonplastic; strongly cemented by lime and silica; 45 percent gravels and 25 percent cobbles; violently effervescent (42 percent calcium carbonate equivalent); moderately alkaline (pH 8.2); abrupt wavy boundary. (4 to 10 inches)
Bkq1--21 to 33 inches; very pale brown (10YR 8/2) extremely gravelly sandy loam, very pale brown (10YR 7/3) moist; massive; very hard, firm, nonsticky and nonplastic; few very fine tubular pores; weakly cemented by lime and silica; 60 percent gravels and 5 percent cobbles; violently effervescent (40 percent calcium carbonate equivalent); moderately alkaline (pH 8.4); clear wavy boundary. (8 to 16 inches thick)
Bkq2--33 to 48 inches; very pale brown (10YR 8/2) extremely gravelly sandy loam, very pale brown (10YR 7/3) moist; massive; very hard, firm, nonsticky and nonplastic; few very fine tubular pores; weakly cemented by lime and silica; 50 percent gravels and 15 percent cobbles; violently effervescent; strongly alkaline (pH 8.8); gradual wavy boundary. (10 to 24 inches thick)
Bkq3--48 to 60 inches; very pale brown (10YR 8/3) extremely gravelly loamy sand, very pale brown (10YR 7/3) moist; massive; very hard, firm, nonsticky and nonplastic; few very fine irregular pores; weakly cemented by lime and silica; 50 percent gravels and 20 percent cobbles; strongly effervescent; strongly alkaline (pH 8.8).
TYPE LOCATION: Bear Lake County, Idaho; about 4 miles southeast of Pegram, about 1,700 feet south and 1,050 feet west of the northeast corner of sec. 28, T. 15S., R. 46E. (Latitude: 42 degrees, 05 minutes, 31 seconds N., Longitude: 111 degrees, 04 minutes, 33 seconds W.)
RANGE IN CHARACTERISTICS:
Soil moisture control section - usually moist, dry for 45 consecutive days or more in the four months following the summer solstice. Xeric soil moisture regime.
Mollic epipedon thickness - 10 to 16 inches
Depth to duripan - 10 to 16 inches
Average annual soil temperature - 39 to 43 degrees F.
Average summer soil temperature - 54 to 59 degrees F. Cryic soil temperature regime.
Particle size control section
Clay content - 10 to 18 percent
Rock fragments - 35 to 65 percent
A horizon
Value: 3 through 5 dry, 2 or 3 moist
Chroma: 2 or 3 dry or moist
Texture: Very gravelly loam or extremely gravelly loam
Clay content: 10 to 18 percent
Rock fragments: 35 to 65 percent -- 35 to 65 percent gravel, 0 to 10 percent cobble
Soil reaction: Neutral to slightly alkaline
AB horizon
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3 dry or moist
Texture: Very gravelly loam or very gravelly silt loam
Clay content - 10 to 18 percent
Rock fragments: 35 to 60 percent -- 30 to 40 percent gravel, 10 to 20 percent cobbles
Effervescence: None to slight
Calcium carbonate equivalent: less than 15 percent
Soil reaction: Slightly alkaline to moderately alkaline
Bw horizon
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3 dry or moist
Texture: Very gravelly loam or very gravelly sandy loam
Clay content - 10 to 18 percent
Rock fragments: 35 to 60 percent -- 30 to 40 percent gravel, 10 to 20 percent cobbles
Effervescence: None to slight
Calcium carbonate equivalent: less than 15 percent
Soil reaction: Slightly alkaline to moderately alkaline
Bkqm horizon:
Resistance ? moderately to very strongly cemented
Bkq1, Bkq2 and Bkq3 horizons
Value: 7 or 8 dry or moist
Chroma: 2 through 4 dry or moist
Texture: Extremely gravelly sandy loam, extremely gravelly loamy sand, or very gravelly loamy sand
Clay content: 3 to 10 percent
Cementation: Weakly or moderately cemented in less than 50% of the volume
Rock fragment: 50 to 85 percent -- 40 to 70 percent gravel, 5 to 25 percent cobbles
Calcium carbonate equivalent: 15 to 40 percent
Soil reaction: Moderately alkaline to strongly alkaline
COMPETING SERIES:
There are no competing series.
GEOGRAPHIC SETTING:
Landform: Terrace summits, ridge tops and fan terraces
Elevation: 6,600 to 7,700 feet
Slope: 3 to 15 percent
Parent material: Alluvium derived from chert, sandstone, and quartzite
Climate: long, cold winters, moist springs, and dry, warm summers.
Mean annual precipitation: 14 to 18 inches
Mean annual temperature: 36 to 41 inches
Frost-free period: 50 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cokeville (T), Pontuge (T), and Slan (T) series. The Cokeville series has an argillic horizon, is deep, and is fine-loamy. Cokeville soils are located on terrace sides, hillsides, and mountainsides formed in sandstone and conglomerate. The Pontuge series is fine-loamy, moderately deep, has a pachic mollic epipedon and has an argillic horizon. Pontuge soils are located on terrace sides and hillsides on alluvium derived from sandstone and conglomerate. The Slan series has an argillic horizon, is moderately deep and is fine-loamy. Slan soils are located on smoother terrace sideslopes.
DRAINAGE AND PERMEABILITY: Well drained; medium and rapid runoff; moderate permeability to duripan.
USE AND VEGETATION: Boundridge soils are used primarily for rangeland and wildlife habitat. Important native plant species are mountain big sagebrush, bluebunch wheatgrass, letterman needlegrass and mountain snowberry.
DISTRIBUTION AND EXTENT: The soils of this series are moderately extensive in southeastern Idaho.
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:
Mollic epipedon - the zone from the soil surface to 14 inches (A, AB, and Bw horizons.)
Duripan - the zone from 14 to 21 inches (Bkqm horizon.)
Particle-size control section - the zone from the soil surface to 14 inches (A, AB, and Bw horizons.)