LOCATION COMMISSARY WY
Tentative Series
IRD DJP-CBR
03/2018
COMMISSARY SERIES
The Commissary series consists of deep, well drained soils that formed in slope alluvium and colluvium over residuum derived from sandstone and shale. These soils are on hillslopes and mountain slopes. Slopes are 4 to 25 percent. Mean annual precipitation is about 500 mm, and mean annual air temperature is about 1.2 degrees C.
TAXONOMIC CLASS: Clayey-skeletal, smectitic Ustic Argicryolls
TYPICAL PEDON: Commissary gravelly silt loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 9 cm; dark grayish brown (10YR 4/2) gravelly silt loam, very dark brown (7.5YR 2.5/2) moist; moderate fine granular structure; soft, very friable, slightly sticky, slightly plastic; many fine, very fine, common medium and coarse roots throughout; many very fine irregular pores; 20 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (8 to 10 cm thick)
Bt1--9 to 30 cm; brown (7.5YR 5/3) gravelly silty clay loam, dark brown (7.5YR 3/3) moist; moderate medium subangular blocky structure; moderately hard, firm, moderately sticky, moderately plastic; common fine, medium and many very fine roots throughout; common fine and very fine dendritic tubular pores; 30 percent gravel; 20 percent distinct clay films on all faces of peds; slightly acid (pH 6.4); clear smooth boundary. (18 to 24 cm thick)
Bt2--30 to 76 cm; light brown (7.5YR 6/3) very gravelly clay, brown (7.5YR 5/4) moist; strong medium subangular blocky structure; hard, very firm, very sticky, very plastic; common fine, medium and many very fine roots throughout; common fine and many very fine dendritic tubular pores; 45 percent gravel; 25 percent distinct clay films on all faces of peds; neutral (pH 6.6); clear smooth boundary. (42 to 50 cm thick)
C--76 to 121 cm; light brown (7.5YR 6/3) very gravelly clay, brown (7.5YR 5/4) moist; massive; hard, very firm, very sticky, very plastic; many very fine dendritic tubular pores; 55 percent gravel; neutral (pH 6.8); abrupt smooth boundary. (40 to 50 cm thick)
Cr--121 cm; shale bedrock.
TYPE LOCATION: Lincoln County, Wyoming; USGS South Fork Mountain, Wyoming, topographic quadrangle; 42 degrees 2 minutes 53.71 seconds north latitude and 110 degrees 32 minutes 40.29 seconds west longitude, datum WGS84.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature -- 1.6 to 3.1 degrees C.
Mollic epipedon thickness -- 26 to 34 cm
Depth to paralithic contact -- 100 to 150 cm
Particle-size control section (weighted averages)
Clay content -- 36 to 44 percent
Total rock fragments -- 35 to 45 percent
A horizon
Hue: 7.5YR or 10YR, dry or moist
Value: 4 or 5 dry; 2 to 3 moist
Chroma: 2 or 3, dry or moist
Clay content: 14 to 20 percent
Rock fragments: 15 to 30 percent gravel
Reaction: pH 6.2 to 6.8
Bt1 horizon
Hue: 7.5YR or 10YR, dry or moist
Value: 5 or 6 dry; 2.5 or 3 moist
Chroma: 3 or 4, dry or moist
Texture (less than 2 mm fraction): silty clay loam
Clay content: 29 to 32 percent
Rock fragments: 20 to 35 percent gravel
Reaction: pH 6.2 to 6.8
Bt2 horizon
Hue: 7.5YR or 10YR, dry or moist
Value: 6 dry; 5 moist
Chroma: 3 or 4, dry or moist
Texture (less than 2 mm fraction): silty clay, clay
Clay content: 42 to 48 percent
Rock fragments: 40 to 50 percent gravel
Reaction: pH 6.4 to 6.8
C horizon
Hue: 7.5YR or 10YR, dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4, dry or moist
Clay content: 50 to 57 percent
Rock fragments: 50 to 65 percent gravel
Reaction: pH 6.4 to 7.0
COMPETING SERIES:
Embargo (CO) -- soils are moderately deep to lithic contact
Evna (CO) -- soils are very deep
Passar (CO) -- soils are very deep
Redchief (MT) -- soils are very deep
Rooset (WY) -- soils are very deep
Tellura (CO) -- soils are very deep
GEOGRAPHIC SETTING:
Landform -- hillslopes and mountain slopes
Elevation -- 2,200 to 2,700 meters
Slope -- 4 to 25 percent
Parent material -- slope alluvium and colluvium over residuum derived from sandstone and shale
Climate - long, cold winters; cool, moist springs; short, cool summers
Mean annual precipitation -- 375 to 550 mm with peak periods of precipitation occurring during the spring
Mean annual air temperature -- 0.6 to 2.1 degrees C.
Frost-free period -- 15 to 45 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained, 0.01 to 15.00 um/sec.
USE AND VEGETATION: Commissary soils are primarily used for rangeland. The potential native vegetation is western wheatgrass, western needlegrass, bluebunch wheatgrass, mountain big sagebrush, aspen, and snowberry.
DISTRIBUTION AND EXTENT: Commissary soils are of small extent in southwestern Wyoming. MLRA 43B and 46.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Lincoln County, Wyoming, 2018. The name is derived from a local landmark.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon -- 0 to 30 cm (A and Bt1 horizons)
Argillic horizon -- 9 to 76 cm (Bt1 and Bt2 horizons)
Paralithic contact -- 121 cm (Cr horizon)
Particle-size control section -- 9 to 59 cm (Bt1 and part of the Bt2 horizons)
Commissary soils have a cryic temperature regime and an ustic moisture regime.
Taxonomic version: Twelfth edition, 2014
National Cooperative Soil Survey
U.S.A.