LOCATION ELKOL WYEstablished Series
TAXONOMIC CLASS: Fine, smectitic, calcareous, frigid Ustertic Torriorthents
TYPICAL PEDON: Elkol silty clay-rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; light gray (2.5Y 7/2) silty clay, light olive brown (2.5Y 5/2) moist; strong fine granular structure, weak, platy in the upper one inch; soft, very friable, very sticky and plastic; strongly effervescent, lime disseminated; very strongly alkaline (pH 9.2); clear smooth boundary. (3 to 6 inches thick)
AC--4 to 11 inches; light gray (2/5Y 7/2) silty clay; light olive brown (2.5Y 5/3) moist; weak coarse angular blocky structure; hard, firm, very sticky and plastic; strongly effervescent, lime disseminated; very strongly alkaline (pH 9.2); diffuse wavy boundary. (0 to 8 inches thick)
C--11 to 60 inches; light gray (2.5Y 7/2) silty clay, light olive brown (2.5Y 5/3) moist; massive; extremely hard, very sticky and plastic; strongly effervescent, lime as few small soft, rounded masses, few crystals of calcium sulfate occurring erratically with depth; very strongly alkaline (pH 9.0).
TYPE LOCATION: Lincoln County, Wyoming; approximately 2,112 feet west and 528 feet north of the SE corner of sec. 27, T. 21 N., R. 116 W.
RANGE IN CHARACTERISTICS: Depth to uniformly calcareous material ranges from 0 to 10 inches. The mean annual soil temperature ranges from 40 to 47 degrees F. The mean summer soil temperature ranges from 59 to 66 degrees F. The particle-size control section is clay loam, silty clay loam, clay, or silty clay, averaging 35 to 45 percent clay. Flat rock fragments or pebbles range from 0 to 15 percent throughout the profile. Exchangeable sodium percentage ranges from 15 to 30 percent in most parts. Conductivity is typically more than 2 mmhos but does not exceed 16 mmhos.
The A horizon has hue of 5Y to 7.5YR, value of 4 through 7 dry, 3 through 6 moist, and chroma of 2 through 4. Reaction is strongly or very strongly alkaline.
The C horizon has hue of 5Y through 7.5YR, value of 4 through 7 dry, 3 through 6 moist, and chroma of 2 through 4. Reaction is moderately through very strongly alkaline. Concentrations of soluble salts, gypsum, and carbonates are common but do not qualify as diagnostic horizons. Some pedons have a layer with texture of very fine sandy loam below the depth of 50 inches. The moisture control section is usually dry, but is moist in some parts for 30 to 50 cumulative days between June 10 and October 10.
COMPETING SERIES: There are no competing series. The Bahl, Limon, and Petrie soils are similar. These soils have mesic temperature regimes and do not have the high ESP common in the Elkol soils.
GEOGRAPHIC SETTING: Elkol soils are on alluvial fans, hillslopes, terraces, and valley fills. Slopes are 0 to 12 percent. The soils formed in moderately fine or fine, calcareous alluvium derived from sodic shales. Elevations are 4,500 to 7,800 feet. The mean annual precipitation ranges from 10 to 14 inches of which about half falls as snow or rain in April, May, and early June. The mean annual temperature is about 39 to 45 degrees F. The frost-free period is estimated to be from 60 to 110 days depending upon elevation, aspect, and air drainage.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Havre, Kemmerer, Moyerson, and Patent soils. These soils have less than 15 percent exchangeable sodium. Havre soils are fluventic and have less than 35 percent clay. Kemmerer soils have a cambic horizon. Moyerson soils have bedrock at depths of less than 20 inches. Patent soils have less than 35 percent clay.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff on low slopes and medium runoff on steeper slopes; slow permeability.
USE AND VEGETATION: These soils are used as rangeland. Native vegetation is Gardner saltbush, greasewood, bottlebrush squirreltail, and western wheatgrass.
DISTRIBUTION AND EXTENT: In the cold intermountain basins of Wyoming. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Fremont County (Lander Area), Wyoming; 1975.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--0 to 2 inches (A)
Ustertic feature - This soil has cracks 1 to 3 cm wide that extend from the surface to depths greater than 50 cm which remain open for 175 to 240 cumulative days.