LOCATION MONUMENTPEAK MT
Tentative Series
Ird. EAW-KTS-EMM
02/2013
MONUMENTPEAK SERIES
The Monumentpeak series consists of shallow, well drained soils that formed in colluvium over residuum derived from limestone and other calcareous rock sources. These soils occur on mountainslopes, canyon walls, ridges and structural benches. Slopes are 4 to 70 percent. Mean annual precipitation is about 710 mm, and mean annual temperature is about 3 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, carbonatic Lithic Calcicryepts
TYPICAL PEDON: Monumentpeak very cobbly silt loam, forested, on a 62 percent northeast slope at an elevation of 2,054 meters (colors are for dry soil unless otherwise noted).
Oi--0 to 2 cm; partially decomposed forest litter. (0 to 6 cm thick)
A--2 to 13 cm; brown (10YR 5/3) very cobbly silt loam, brown (10YR 4/3) moist; weak fine and medium granular structure, soft, very friable, nonsticky and nonplastic; many fine roots; common very fine and fine pores; 20 percent gravel and 30 percent cobbles; continuous distinct calcium carbonate coatings on underside of fragments; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (5 to 20 cm thick)
Bk1--13 to 23 cm; light yellowish brown (10YR 6/4) very cobbly silt loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine roots, common medium roots; common very fine and fine pores; 25 percent gravel and 30 percent cobbles; continuous prominent calcium carbonate casts on bottoms of rock fragments, and finely disseminated calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary.
Bk2--23 to 46 cm; very pale brown (10YR 7/4) extremely cobbly silt loam, yellowish brown (10YR 5/4) moist; weak fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine and fine roots, few coarse roots; common very fine and fine pores; 25 percent gravel and 45 percent cobbles; continuous prominent calcium carbonate casts on bottoms of rock fragments, and finely disseminated calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (combined thickness of Bk horizons - 20 to 45 cm)
R--46 cm; hard, gray, fossiliferous limestone.
TYPE LOCATION: Meagher County, Montana; Monument Peak topographic quadrangle; UTM 12T, 492919e., 5204719n. NAD 83
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 1 to 4 degrees C.
Depth to a lithic contact - 25 to 50 cm
Particle-size control section (weighted average) - greater than 35 percent rock fragments
A horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 2 or 3; dry or moist
Clay content: 15 to 27 percent
Texture: silt loam or loam
Rock fragments: 35 to 60 percent gravel or cobbles
Calcium carbonate equivalent: 5 to 25 percent
Reaction: pH 7.9 to 8.4
Bk horizons
Hue: 10YR or 2.5Y; dry or moist
Value: 5 to 8 dry; 4 to 7 moist
Chroma: 2, 3 or 4; dry or moist
Clay content: 15 to 27 percent
Texture: silt loam or loam
Rock fragments: 35 to 80 percent gravel or cobbles
Calcium carbonate equivalent: 40 to 60 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES:
Henneberry (MT) - has hues redder than 10YR and an ustic moisture regime
Tropal (MT) - has an ustic moisture regime
GEOGRAPHIC SETTING:
Landform - mountainslopes, canyon walls, ridges and structural benches
Elevation - 1980 to 2750 meters
Slope - 4 to 70 percent
Parent material - colluvium over residuum derived from limestone and calcareous rock sources.
Climate - long, cold winters; cool, moist springs; cool summers
Mean annual precipitation - 610 to 890 mm
Mean annual air temperature - 1 to 4 degrees C.
Frost-free period - 30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Monumentpeak soils are used mainly for wildlife and recreation. Potential native vegetation is mainly Douglas-fir, Subalpine Fir, Whitebark pine, limber pine, common juniper, common snowberry, Rocky Mountain clematis, bearberry, birchleaf spirea, northern bedstraw and Oregon grape. In rangeland the potential vegetation is rough fescue, mountain brome, purple oniongrass, littleflower sunflower and shrubby cinquefoil.
DISTRIBUTION AND EXTENT: Monumentpeak soils are of small extent in central Montana. MLRA 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES PROPOSED: Meagher County, Montana, 2012. Monumentpeak series is named for a mountain on the Monument Peak quadrangle.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 13 cm (Oi, A horizons)
Calcic horizon - from 13 to 46 cm (Bk1, Bk2 horizons)
Lithic contact - at 46 cm (R horizon)
Particle-size control section - from 25 to 46cm (part of Bk horizon)
Monumentpeak soils have a cryic temperature regime and a udic moisture regime.
Taxonomic version: Eleventh Edition, 2010.
National Cooperative Soil Survey
U.S.A.