LOCATION MAWSPRING          MT
Established Series
JMS/EMM/RJS
01/2007

MAWSPRING SERIES


The Mawspring series are very deep, well drained soils that formed in alluvium and colluvium derived from argillite, quartzite and sandstone. These soils are on fan remnants, hills and mountains. Slopes are 6 to 45 percent. Mean annual precipitation is about 432 millimeters and mean annual air temperature is about 3 degrees C.

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.


National Cooperative Soil Survey
U.S.A.