LOCATION LIBEG MT+CO

Established Series
Rev. CNG-KTS-RJS
04/2011

LIBEG SERIES

The Libeg series consists of very deep, well drained soils that formed in alluvium, outwash, colluvium, till or slide deposits. These soils are on stream terraces, alluvial fans, fan remnants, alpine moraines, outwash plains, hills, mountain slopes, ridges, escarpments, avalanche chutes and landslides. Slopes are 0 to 70 percent. Mean annual precipitation is about 22 inches, and mean annual air temperature is about 40 degrees F.

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 very fine and fine granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots and few medium roots; many very fine and 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 very fine and fine roots; many very fine and 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 sandstone channers; 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 very fine and fine angular blocky structure; very hard, friable, moderately sticky and moderately plastic; many very fine and fine roots; many very fine and 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 channers; 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 very fine and fine roots and few coarse roots; many very fine and fine pores and 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. (combined thickness of Bt horizons - 19 to 40 inches)

BC--30 to 60 inches; light reddish brown (5YR 6/4) very stony sandy loam, yellowish red (5YR 5/6) moist; weak fine and medium subangular blocky structure; very hard, friable, moderately sticky and moderately plastic: few very fine and fine roots; common very fine and fine pores; 80 percent sandstone fragments; 30 percent angular gravel and 50 percent stones; 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. 17N, R. 6E.

RANGE IN CHARACTERISTICS:
Soil temperature: 35 to 44 degrees F.
Mollic epipedon thickness: 7 to 15 inches
Depth to top of argillic horizon - 4 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; dry or moist
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 1 to 3; dry or moist
Texture: loam, clay loam, silty clay loam or sandy loam
Clay content: 10 to 40 percent
Rock fragments: 10 to 60 percent--5 to 50 percent gravel, 0 to 50 percent cobbles and stones
Reaction: pH 5.6 to 7.3

Bt1, Bt2 horizons
Hue: 5YR, 7.5YR or 10YR; dry or moist
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--10 to 45 percent gravel, 5 to 50 percent cobbles and stones
Reaction: pH 5.6 to 7.8

Bt3 horizon
Hue: 5YR to 10YR; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 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--10 to 50 percent gravel, 5 to 50 percent cobbles and stones
Reaction: pH 5.6 to 7.3

BC horizon
Hue: 5YR to 10YR; dry or moist
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 22 percent
Rock fragments: 40 to 85 percent--30 to 55 percent gravel, 10 to 50 percent cobbles and stones
Reaction: pH 5.6 to 7.8

COMPETING SERIES:
Anniesdraw (WY) - have a lithologic discontinuity
Bassel (CO) - are deep to a paralithic contact
Blaine (MT) - are moderately deep to a lithic contact
Bowen (CO) - are moderately deep to a lithic contact
Fingerrock (CO) - have a C horizon with less than 10 percent clay
Fornor (WY) - have secondary calcium carbonate accumulation
Fourmile (CO) - have a lithologic discontinuity
Geertsen (UT) - are deep to a lithic contact
Hoodle (UT) - have secondary calcium carbonate accumulation
Hungryhill (MT) - are moderately deep to a lithic contact
Lagarita (CO) - have secondary calcium carbonate accumulation
Lambe (CO) - have secondary calcium carbonate accumulation
Nathale (WY) - are moderately deep to a lithic contact
Nathrop (CO) - are moderately deep to a lithic contact
Norriston (CO) - have a lithologic discontinuity
Quander (CO) - have a soil moisture control section that is usually moist in mid to late summer
Ratiopeak (MT) - have secondary calcium carbonate accumulation
Silverheels (CO) - greatest amount of precipitation occurs during July and August
Spanpeak (MT) - have an O horizon
Woodhall (CO) - are moderately deep to a lithic contact

GEOGRAPHIC SETTING:
Landform: stream terraces, alluvial fans, fan remnants, alpine moraines, outwash plains, hills, mountain slopes, ridges, escarpments, avalanche chutes and landslides
Elevation: 4,500 to 8,500 feet
Slope: 0 to 70 percent
Parent material: alluvium, outwash, colluvium, till or slide deposits
Climate: long, cold winters; cool, moist springs; short summers
Mean annual precipitation: 14 to 30 inches with the greatest amount of precipitation occurring during May and June
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; MLRAs - 43B, 44B, 46, 47, 48A, 49.

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

SERIES ESTABLISHED: Glacier County area, Montana, 1969.

REMARKS: Diagnostic horizons and features recognized in this soil are:
Mollic epipedon - from 0 to 11 inches (A, Bt1 horizons)
Argillic horizon - from 6 to 30 inches (Bt1, Bt2, Bt3 horizons)
Particle-size control section - from 6 to 26 inches. (Bt1, Bt2, part of Bt3 horizons)

Libeg soils have a cryic temperature regime and an ustic moisture regime that borders on udic.

ADDITIONAL DATA: Soil interpretation records - MT0109, MT1034, MT8160, MT1041, MT0353, MT0788, MT3152.

Classification changed from Argic Cryoboroll to Ustic Argicryoll 7/98.

National Cooperative Soil Survey
U.S.A.