LOCATION MAWSPRING MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Ustic Haplocryepts
TYPICAL PEDON: Mawspring very channery loam, in rangeland on a 27 percent slope at 2,100 meters elevation (colors are for dry soil unless otherwise indicated).
A--0 to 15 cm; dark grayish brown (10YR 4/2) very channery loam, very dark grayish brown (10YR 3/2) moist; weak very fine granular structure; very friable, soft, nonsticky and slightly plastic; many very fine and fine roots; many fine irregular pores; 35 percent channers; slightly acid (pH 6.4); clear smooth boundary. (10 to 25 cm thick)
Bw--15 to 33 cm; light yellowish brown (10YR 6/4) very channery loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; very friable, slightly hard, slightly sticky and slightly plastic; common very fine and fine roots; common fine irregular pores; 45 percent channers; neutral (pH 6.6); gradual wavy boundary. (15 to 70 cm thick)
BC--33 to 84 cm; light yellowish brown (10YR 6/4) extremely channery loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; very friable, slightly hard, slightly sticky and slightly plastic; few very fine roots; common fine irregular pores; 65 percent channers; neutral (pH 6.6); gradual irregular boundary. (25 to 70 cm thick)
C--84 to 152 cm; light olive brown (2.5Y 5/4) extremely channery sandy loam, olive brown (2.5Y 4/4) moist; massive; very friable, slightly hard, slightly sticky and slightly plastic; common fine irregular pores; 65 percent channers; neutral (pH 6.6).
TYPE LOCATION: Wickiup Creek topographic quadrangle, Silver Bow County, Montana; 690 meters north and 675 meters east of the SW corner of section 24, T. 1 S., R. 8 W. UTM Zone 12: 380368e, 5065699n, NAD 83.
RANGE IN CHARACTERISTICS:
Soil temperature - 2 to 6 degrees C
Moisture control section - 20 to 60 cm
Surface fragments - 0 to 3 percent stones
A horizon
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 2 to 4, dry or moist
Texture: loam, sandy loam or loamy sand
Clay content: 10 to 25 percent
Rock fragments: 15 to 75 percent--10 to 40 percent channers or angular gravel, 0 to 25 percent cobbles, 0 to 10 percent stones
Reaction: pH 6.0 to 7.2
Bw horizon
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 to 4 dry or moist
Texture: sandy loam or loam
Clay content: 12 to 27 percent
Rock fragments: 35 to 75 percent--35 to 55 percent channers or angular gravel, 0 to 15 percent cobbles, 0 to 10 percent stones
Reaction: pH 6.0 to 7.2
BC horizon
Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4 dry or moist
Texture: sandy loam or loam
Clay content: 10 to 25 percent
Rock fragments: 50 to 85 percent--35 to 60 percent channers or angular gravels, 0 to 20 percent cobbles, 0 to 10 percent stones
Reaction: pH 6.0 to 7.6
C horizon
Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4 dry or moist
Texture: loam or sandy loam
Clay content: 8 to 20 percent
Rock fragments: 55 to 85 percent-35 to 60 percent channers or angular gravels, 0 to 15 percent cobbles, 0 to 10 percent stones
Reaction: pH 6.0 to 7.8
COMPETING SERIES:
Danavore (CO) - is moderately deep to a paralithic contact.
Ellena (MT) - is moderately deep to a paralithic contact.
Elve (MT) - has an E horizon 15 to 63 cm thick.
Hiore (MT) - has coarse sandy loam or loamy coarse sand textures throughout.
Millswitch (CO) - deep to a paralithic contact.
Pergrin (CO) - is moderately deep to a lithic.
Rubick (MT) - has greater than 15 percent cobbles and/or stones throughout.
Scout (UT) - has a udic soil moisture regime.
Shadow (MT) - has 15 to 40 percent mica in the particle-size control section.
Taglake (WY) - contains more than 15 percent cobbles and stones throughout.
Vandamore (CO) - moderately deep to a lithic contact.
GEOGRAPHIC SETTING:
Landform - fan remnants, hills and mountains
Elevation - 1,609 to 2,381 meters
Slope - 6 to 45 percent
Parent material - gravelly or channery alluvium and colluvium derived from argillite, quartzite and sandstone
Climate - long, cold winters; cold, moist springs; short, cool summers
Mean annual precipitation - 381 to 483 millimeters, much of which falls as snow and as spring rain
Mean annual air temperature - 1 to 5 degrees centigrade
Frost-free period - 30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Soapgulch, Surdal and Sigbird soils which occur on similar landforms. Soapgulch soils have a mollic epipedon. Surdal soils are moderately deep to aa lithic contact. Sigbird soils are shallow to a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Mawspring soils are used mainly for rangeland. Potential native vegetation is Idaho fescue, bluebunch wheatgrass, rough fescue, prairie junegrass, big sagebrush and Rocky Mountain juniper.
DISTRIBUTION AND EXTENT: Mawspring soils are of small extent in the intermontane basins of central Montana. MLRA 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Silver Bow County, Montana, 2006.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 15 cm (A horizon)
Cambic horizon - 15 to 33 cm (Bw horizon)
Particle-size control section - from 25 to 100 cm
Mawspring soils have a cryic temperature regime and an ustic moisture regime.