LOCATION BAIRSPRING MT
Tentative Series
Ird. EMM/RJS
05/2014
BAIRSPRING SERIES
The Bairspring series consists of moderately deep, well drained soils that formed in colluvium over residuum derived from igneous or sedimentary rock. These soils are on escarpments, hills, ridges and mountain slopes. Slopes are 8 to 45 percent. Mean annual precipitation is about 530 mm, and mean annual air temperature is about 2.8 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Ustic Haplocryolls
TYPICAL PEDON: Bairspring cobbly loam, in forest (colors are for dry soil unless otherwise noted).
Oi--0 to 3 cm; slightly decomposed needles and twigs. (0 to 4 cm thick)
A1--3 to 11 cm; dark grayish brown (10YR 4/2) cobbly loam, black (10YR 2/1) moist; weak fine and medium granular structure; slightly hard, very friable, slightly sticky and nonplastic; common very fine and fine, and few medium and coarse roots; many very fine and fine interstitial pores; 15 percent gravel, 10 percent cobble; slightly acid (pH 6.5); clear smooth boundary.
A2--11 to 23 cm; brown (10YR 4/3) very cobbly loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky; slightly hard, very friable, slightly sticky and nonplastic; common very fine and fine, and few medium roots; many very fine and fine interstitial pores; 15 percent gravel, 25 percent cobbles; neutral (pH 6.6); gradual wavy boundary. (Combined thickness of A horizons is 18 to 25 cm).
Bw1--23 to 51 cm; grayish brown (10YR 5/2) extremely cobbly loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky; slightly hard, very friable, slightly sticky and nonplastic; few very fine, fine, and medium roots; many very fine and fine interstitial pores; 25 percent gravel, 40 percent cobbles; neutral (pH 6.6); gradual smooth boundary. (25 to 45 cm thick)
C--51 to 72 cm; brown (10YR 5/3) extremely cobbly sandy loam, brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsicky and nonplastic; few very fine and fine roots and few medium roots; common very fine and fine interstitial pores; 25 percent gravel, 45 percent cobbles; neutral (pH 6.6); clear wavy boundary.
R--72 inches; hard, slightly fractured rhyolite.
TYPE LOCATION: Meagher County Montana, located about 300 meters west and 570 meters north of the south east corner of section 10, T 9N, R 8E; Fourmile Spring topographic quadrangle; UTM 12T, 523269e, 5155571n, NAD 83.
RANGE IN CHARACTERISTICS:
Soil temperature - 2 to 5 degrees C.
Mollic epipedon thickness - 18 to 25 cm
Depth to a lithic contact - 50 to 100 cm
Clay content - averages less than 18 percent in the particle-size control section.
A horizons
Value: 3 or 4 dry; 2 or 3 moist
Chroma: 1 or 2, dry or moist
Clay content: 10 to 18 percent
Texture: loam or sandy loam
Rock fragments: 15 to 50 percent--10 to 35 percent gravel or channers, 0 to 25 percent cobbles or stones
Reaction: pH 6.1 to 7.3
Bw1 horizon
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3; dry or moist
Texture: loam or sandy loam
Clay content: 10 to 18 percent
Rock fragments: 35 to 60 percent--25 to 40 percent gravel or channers, 5 to 40 percent cobbles
Reaction: pH 6.0 to 6.8
C horizon (where present)
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3; dry or moist
Texture: loam or sandy loam
Clay content: 10 to 18 percent
Rock fragments: 35 to 80 percent--20 to 60 percent gravel or channers, 0 to 40 percent cobbles
Reaction: pH 6.0 to 6.8
BC horizon present in some pedons.
COMPETING SERIES:
Antrobus (CO) - are very deep
Brushfire (WY) - are very deep
Grafen (CO) - are very deep
Greyback (WY) - are very deep
Handran (CO) - are very deep
Maurice (MT) - are very deep
Mccort (WY) - are very deep
Midelight (WY) - are deep to a lithic contact
Parachute (CO) - have more than 18 percent clay in the particle-size control section
Sebud (MT) - are very deep
Supervisor (NM) - do not have a cambic horizon
Surdal (MT) - have more than 18 percent clay in the particle-size control section
Teemat (WY) - are very deep
Thornburgh (CO) - are very deep
Tiban (MT) - are very deep
Tineman (WY) - are very deep
Vanwirt (CO) - are very deep
GEOGRAPHIC SETTING:
Landform - escarpments, hills, ridges and mountain slopes
Elevation - 1,700 to 2,500 meters
Slope - 8 to 45 percent
Parent material - colluvium over residuum derived from igneous or sedimentary rock
Climate - long, cold winters; cool, moist springs; short, cool summers
Mean annual precipitation - 480 to 610 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: Bairspring soils are primarily used for wildlife habitat and watershed. The potential native vegetation is mainly Douglas-fir, lodgepole pine, Idaho fescue, rough fescue, Richardson needlegrass, Columbia needlegrass, parry danthonia, mountain brome, lupine, sticky geranium, hoods phlox and snowberry.
DISTRIBUTION AND EXTENT: Bairspring soils are of small extent in southwestern Montana. MLRA - 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES PROPOSED: Meagher County, Montana, 2014. The name is from a nearby spring.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 3 to 23 cm (A1, A2 horizons)
Cambic horizon - from 23 to 51 cm (Bw horizon)
Lithic contact - at 72 cm (R horizon)
Particle-size control section - from 25 to 72 cm (part of the Bw, and the C horizons)
Bairspring soils have a cryic temperature regime and an ustic moisture regime.
National Cooperative Soil Survey
U.S.A.