LOCATION LIBEG MT+COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Ustic Argicryolls
TYPICAL PEDON: Libeg stony loam, grassland (colors are for dry soil unless otherwise noted).
A--0 to 6 inches; dark grayish brown (10YR 4/2) stony loam, black (10YR 2/1) moist; weak thin platy structure parting to moderate fine and very fine granular; slightly hard, very friable, slightly sticky and slightly plastic; many fine and very fine roots, few medium roots; many fine and very fine pores; 25 percent sandstone fragments; slightly acid (pH 6.4); clear wavy boundary. (4 to 15 inches thick)
Bt1--6 to 11 inches; brown (10YR 5/3) very channery loam, dark brown (10YR 3/3) moist; strong very fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many fine and very fine roots; many fine and very fine pores; pale brown (10YR 6/3) fine sand coatings on some faces of peds; faint clay films on faces of some peds and on rock fragments; 35 percent channery sandstone fragments; slightly acid (pH 6.5); clear wavy boundary.
Bt2--11 to 16 inches; brown (7.5YR 5/4) very channery clay loam, brown (7.5YR 4/4) moist; strong fine and very fine angular blocky structure; very hard, friable, moderately sticky and moderately plastic; many fine and very fine roots; many fine and very fine pores; pale brown (10YR 6/3) fine sand coatings on vertical faces of peds; faint clay films on faces of some peds and on rock fragments; 40 percent sandstone fragments; slightly acid (pH 6.5); clear wavy boundary.
Bt3--16 to 30 inches; reddish brown (5YR 5/4) very channery sandy clay loam, reddish brown (5YR 4/4) moist; strong fine and medium angular blocky structure; extremely hard, friable, moderately sticky and moderately plastic; common fine and very fine roots, few coarse roots; many fine and very fine pores, few medium pores; distinct continuous clay films on all faces of peds and on rock fragments; 60 percent channers; slightly acid (pH 6.2); gradual irregular boundary. (Bt horizons are 19 to 40 inches thick)
BC--30 to 60 inches; light reddish brown (5YR 6/4) very stony sandy loam, yellowish red (5YR 5/6) moist; weak medium and fine subangular blocky structure; very hard, friable, moderately sticky and moderately plastic: few fine and very fine roots; common fine and very fine pores; 80 percent sandstone fragments; 50 percent stones, 30 percent angular gravel; slightly acid (pH 6.5). (0 to 50 inches thick)
TYPE LOCATION: Cascade County, Montana; 1,900 feet west and 2,280 feet south of the NE corner of sec. 16, T. 17 N., R. 6 E.
RANGE IN CHARACTERISTICS:
Soil moisture regime: Ustic moisture regime that borders on udic.
Soil temperature: 35 to 44 degrees F.
Mollic epipedon thickness: 7 to 15 inches.
Rock fragments: mainly argillite, igneous, quartzite, and sandstone
Surface fragments: 0 to 15 percent stones and/or boulders
A horizon:
Hue: 7.5YR or 10YR
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 1 to 3
Texture: loam, clay loam, silty clay loam, or sandy loam
Clay content: 10 to 40 percent
Rock fragments: 10 to 60 percent--0 to 50 percent stones and cobbles; 5 to 50 percent gravel
Reaction: pH 5.6 to 7.3
Bt1 and Bt2 horizons:
Hue: 5YR, 7.5YR, or 10YR
Value: 4 to 6 dry; 3 to 5 moist
Chroma: 2 to 6 dry or moist
Texture: loam, sandy loam, sandy clay loam, or clay loam
Clay content: 15 to 35 percent
Rock fragments: 35 to 80 percent--5 to 50 percent stones and cobbles; 10 to 45 percent gravel
Reaction: pH 5.6 to 7.8
Bt3 horizon:
Hue: 5YR to 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 to 6 dry or moist
Texture: clay loam, sandy clay loam, or loam
Clay content: 20 to 35 percent
Rock fragments: 35 to 85 percent--5 to 50 percent stones and cobbles; 10 to 50 percent gravel
Reaction: pH 5.6 to 7.3
BC horizon:
Hue: 5YR to 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 to 6 dry or moist
Texture: sandy loam, sandy clay loam, or loam
Clay content: 10 to 20 percent
Rock fragments: 40 to 85 percent--10 to 50 percent stones and cobbles; 30 to 45 percent gravel
Reaction: pH 5.6 to 7.8
COMPETING SERIES:
Blaine (MT) has lithic contact at depths of 40 inches or less.
BOWEN (CO), Nathale (WY), NATHROP (CO), WOODHALL (CO) have lithic contact at depths of 40 inches or less.
FINGERROCK (CO) has a C horizon with less than 10 percent clay.
FORNOR (WY), HODDEN (CO), HOODLE (UT), LAGARITA (CO), Ratiopeak (MT) have an accumulation of secondary calcium carbonate.
FOURMILE (CO)- has a lithologic discontinuity at depth of 40 inches or less.
GEERTSEN (UT) has a lithic contact at depths between 40 and 60 inches.
NORRISTON (CO) - has sandy-skeletal materials above a depth of 40 inches.
QUANDER (CO) - has a C horizon with greater than 20 percent clay
SPANPEAK (MT) - has an O horizon
GEOGRAPHIC SETTING:
Landform: mountains; avalanche chutes, landslides; alluvial fans; stream terraces; alpine moraines; hills; escarpments and outwash plains.
Elevation: 4,500 to 8,500 feet.
Slope: 0 to 70 percent.
Parent material: colluvium, alluvium, till containing various kinds of rock fragments.
Climate: long, cold winters; cool, moist springs; short summers.
Mean annual precipitation: 14 to 30 inches.
Mean annual air temperature: 34 to 42 degrees F.
Frost-free period: 30 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Adel and Copenhaver series. Adel soils have less than 35 percent rock fragments and do not have an argillic horizon. Copenhaver soils are shallow.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Libeg soils are used mainly as rangeland. Potential native vegetation is mainly rough fescue, subalpine needlegrass, Idaho fescue, bluebunch wheatgrass, timber danthonia, forbs, and shrubs.
DISTRIBUTION AND EXTENT: Libeg soils are of moderate extent along the eastern front of the Rocky Mountains in central Montana and Colorado. LRR E.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Glacier County area, Montana, 1969.
REMARKS: Soil interpretation records: MT0109, MT1034, MT8160, MT1041, MT0353, MT0788, MT3152.
Diagnostic horizons and features recognized in this soil are:
Particle-size control section: The zone from 6 to 26 inches. (Bt1, Bt2, and Bt3 horizons)
Mollic epipedon: The zone from the soil surface to 11 inches. (A and Bt1 horizons)
Argillic horizon: The zone from 11 to 30 inches. (Bt1, Bt2, and Bt3 horizons)
Taxonomic version: Classified according to Ninth Edition, 2003.
Classification changed from Argic Cryoboroll to Ustic Argicryoll 7/98.