LOCATION MONTSWEET WY
Tentative Series
IRD DMM-DJP-CBR
04/2018
MONTSWEET SERIES
The Montsweet series consists of moderately deep, somewhat excessively to well drained soils that formed in eolian sands over residuum weathered from sandstone. These soils are on hillslopes. Slopes are 15 to 40 percent. Mean annual precipitation is about 250 mm, and mean annual air temperature is about 6.0 degrees C.
TAXONOMIC CLASS: Mixed, frigid Aridic Ustipsamments
TYPICAL PEDON: Montsweet sandy loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 10 cm; brown (10YR 5/3) sandy loam, brown (10YR 4/3) moist; single grain; loose, nonsticky, nonplastic; many fine roots; many fine interstitial pores; 5 percent gravel; neutral (pH 7.2); clear smooth boundary. (7 to 10 cm thick)
BC--10 to 23 cm; yellowish brown (10YR 5/4) sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; very friable, soft, nonsticky, nonplastic; many fine roots; many fine interstitial pores; 2 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary. (6 to 14 cm thick)
C1--23 to 45 cm; light olive brown (2.5Y 5/3) loamy sand, olive brown (2.5Y 4/3) moist; single grain; loose, nonsticky, nonplastic; few fine roots; many fine interstitial pores; 10 percent paragravel; slightly effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (18 to 26 cm thick)
C2--45 to 80 cm; light yellowish brown (2.5Y 6/3) very paragravelly loamy sand, light olive brown (2.5Y 5/3) moist; single grain; loose, nonsticky, nonplastic; few fine roots; many fine interstitial pores; 40 percent paragravel; slightly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (30 to 40 cm thick)
Cr--80 cm; sandstone bedrock.
TYPE LOCATION: Sweetwater County, Wyoming; USGS Picket Lake, Wyoming, topographic quadrangle; 42 degrees 15 minutes 25.36 seconds north latitude and 108 degrees 27 minutes 7.40 seconds west longitude datum WGS84.
RANGE IN CHARACTERISTICS:
Soil temperature -- 6.0 to 8.0 degrees C.
Depth to paralithic contact -- 50 to 100 cm
Particle-size control section (weighted averages)
Clay content -- 3 to 7 percent
Total rock fragments -- 10 to 30 percent
A horizon
Hue: 2.5Y or 10YR, dry or moist
Value: 4 or 5, dry or moist
Chroma: 3 or 4, dry or moist
Clay content: 7 to 10 percent
Rock fragments: 0 to 10 percent gravel
Reaction: pH 7.2 to 7.6
BC horizon
Hue: 2.5Y or 10YR, dry or moist
Value: 4 or 5, dry or moist
Chroma: 3 or 4, dry or moist
Texture (less than 2 mm fraction): sandy loam, loamy sand
Clay content: 7 to 10 percent
Rock fragments: 0 to 10 percent gravel
Reaction: pH 7.4 to 7.8
C1 horizon
Hue: 2.5Y or 10YR, dry or moist
Value: 4 or 5, dry or moist
Chroma: 3 or 4, dry or moist
Texture (less than 2 mm fraction): loamy sand, loamy coarse sand
Clay content: 3 to 7 percent
Parafragments: 5 to 20 percent paragravel
Reaction: pH 7.4 to 8.2
C2 horizon
Hue: 2.5Y or 10YR, dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4, dry or moist
Clay content: 3 to 7 percent
Parafragments: 30 to 45 percent paragravel
Reaction: pH 7.4 to 8.2
COMPETING SERIES:
Dearjosh (CO)-- soils are very deep
Marthaspeak (CO) -- soils are moderately deep to lithic contact
Trey (SD) -- soils have multiple paralithic contacts and lack parafragments
Tusler (ND) -- soils do not have a BC horizon
Yetull (MT) -- soils are very deep
Zeona (SD) -- soils are very deep
GEOGRAPHIC SETTING:
Landform -- hillslopes
Elevation -- 2,080 to 2,165 meters
Slope -- 15 to 40 percent
Parent material -- eolian sands over residuum weathered from sandstone
Climate -- long, cold winters; cool, moist springs; short, warm summers
Mean annual precipitation -- 225 to 325 mm with peak periods of precipitation occurring during the spring
Mean annual air temperature -- 5.0 to 7.0 degrees C.
Frost-free period -- 40 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively to well drained, 15.0-150.0 um/sec.
USE AND VEGETATION: Montsweet soils are primarily used for rangeland. The potential native vegetation is Wyoming big sagebrush, thickspike wheatgrass, threadleaf sedge, Indian ricegrass, and needle and thread.
DISTRIBUTION AND EXTENT: Montsweet soils are of small extent in southwestern Wyoming. MLRA 34A.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Sweetwater County, Wyoming, 2017. The name is derived from a local landmark.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon -- 0 to 10 cm (A horizon)
Paralithic contact -- 80 cm (Cr horizon)
Particle-size control section -- 25 to 80 cm (part of the C1 and C2 horizons)
Montsweet soils have a frigid temperature regime and an ustic moisture regime and an aridic moisture subclass.
Taxonomic version: Twelfth edition, 2014
National Cooperative Soil Survey
U.S.A.