LOCATION SOUTHACE WYEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, calcareous, frigid Ustic Torriorthents
TYPICAL PEDON: Southace gravelly loam-rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; brown (7.5YR 4/4) gravelly loam, dark brown (7.5YR 3/2) moist; moderate medium granular structure; soft, very friable, slightly sticky and slightly plastic; few fine roots; slightly effervescent, lime disseminated; 15 percent pebbles and 5 percent cobbles; moderately alkaline (pH 8.4); clear smooth boundary. (2 to 6 inches thick)
C1--4 to 9 inches; reddish brown (5YR 4/4) very gravelly loam, dark reddish brown (5YR 3/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; violently effervescent, lime disseminated and as common soft masses and filaments; 25 percent pebbles and 10 percent cobble; strongly alkaline (pH 8.6); gradual wavy boundary. (4 to 15 inches thick)
C2--9 to 40 inches; reddish brown (5YR 5/4) very gravelly loam, reddish brown (5YR 4/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; violently effervescent, lime disseminated and as common soft masses and filaments; 35 percent pebbles and 10 percent cobbles; strongly alkaline (pH 8.6); gradual wavy boundary. (20 to 40 inches thick)
C3--40 to 60 inches; reddish brown (5YR 5/4) very cobbly loam, reddish brown (5YR 4/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; violently effervescent, lime disseminated and as common soft masses; 30 percent pebbles and 25 percent cobbles; strongly alkaline (pH 8.6).
TYPE LOCATION: Sweetwater County, Wyoming; 500 feet south of the center of sec. 17, T. 12 N., R. 104 W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 41 to 46 degrees F., and the mean summer temperature is 59 to 63 degrees F. These soils are typically calcareous to the surface, but some pedons are leached a few inches in the surface horizon. The particle-size control section has a matrix texture of loam or sandy loam with 10 to 27 percent clay. Coarse fragments are highly variable and range from 35 to 80 percent pebbles, cobbles, and stones. Either class may dominate or be uniformly mixed.
The A horizon has hue of 10YR through 5YR, value of 4 through 6 dry, 3 or 4 moist, and chroma of 3 through 6. It is mildly alkaline or moderately alkaline.
The C horizon has hue of 7.5YR or 5YR, value of 4 through 6 dry, 3 through 5 moist, and chroma of 2 through 6. Carbonates range from 4 to 14 percent. The segregations of carbonate appear to be a result of the wetting cycles involved when the material was laid down and not a result of pedogenetic development. It is moderately alkaline or strongly alkaline.
COMPETING SERIES: These are the Armells, Colhill, Grobutte, and Grotte series. The Armells soils formed in materials weathered from baked shale. The Colhill, Grobutte, and Grotte soils have hue of 10YR or 2.5Y throughout the control section.
GEOGRAPHIC SETTING: Southace soils are on upper fan aprons, terrace slopes, and mountain or hill slopes. They formed in skeletal, calcareous slope alluvium and sediments derived from red sedimentary rock. Slopes are 1 to 65 percent. Elevations range from 7,300 to 8,500 feet. The mean annual precipitation ranges from 10 to 16 inches of which about half falls as snow or rain in April, May, and early June. The mean annual temperature is about 40 to 45 degrees F. The frost-free season is about 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dahlquist, Teemat, and the competing Grobutte series. Dahlquist soils have argillic horizons. The Teemat soils have mollic epipedons, are cooler, and occur on more north facing slopes.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately rapid or moderate permeability.
USE AND VEGETATION: Rangeland and wildlife habitat. Native vegetation consists of bluebunch wheatgrass, big sagebrush, western or thickspike wheatgrass, serviceberry, and black sagebrush.
DISTRIBUTION AND EXTENT: Southwestern Wyoming and northwestern Colorado. The series is of limited extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Aspen-Gypsum Area, Colorado; 1982.
REMARKS:
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.