LOCATION CROWHEART WYEstablished Series
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, calcareous, mesic Typic Halaquepts
TYPICAL PEDON: Crowheart loam, native grassland. (Colors are for dry soil unless otherwise noted.)
Az--0 to 10 inches; light brownish gray (2.5Y 6/2) loam, grayish brown (2.5Y 5/2) moist; common medium distinct redox conentrations of dark brown (10YR 3/3) and dark yellowish brown (10YR 3/4) moist in the lower half of the horizon; moderate fine granular structure; soft, very friable; 1/4 to 1/2 inch salt crust at the surface; crystals and concretions of soluble salts throughout the horizon; calcareous; very strongly alkaline (pH 9.5); gradual wavy boundary. (6 to 12 inches thick)
Bg--10 to 30 inches; light brownish gray (2.5Y 6/2) fine sandy loam stratified with loam, grayish brown (2.5Y 5/2) moist; common large distinct redox concentrations of brown (10YR 4/3) and dark brown (10YR 3/3), grayish brown (2.5Y 5/2) moist; common large distinct mottles of brown (10YR 4/3) and dark brown (10YR 3/3) moist; massive; slightly hard, very friable; calcareous; moderately alkaline (pH 8.4) abrupt wavy boundary. (14 to 28 inches thick)
IIC--30 to 60 inches; calcareous sand and gravel, strongly mottled throughout. (Several feet thick)
TYPE LOCATION: Fremont county, Wyoming; approximately 1,190 feet west and 1,056 feet south of the NE corner of sec. 4, T.2N., R.1E.
RANGE IN CHARACTERISTICS: These soils are calcareous at the surface and the surface horizon is both very alkaline and saline. Solum thickness ranges from 15 to 40 inches, and depth to contrasting sand and gravel substratums ranges from 20 to 40 inches. Content of organic carbon in the surface horizon ranges from .3 to 1 percent and decreases irregularly with depth. Conductivity of the upper part of the solum ranges from 4 to 10 or more millimhos and decreases with depth. Exchangeable sodium percentage is usually about 20 percent in the surface horizons but ranges from 15 to 30 percent and decreases rapidly with depth in the Bg horizon. The control section is highly stratified but has a weighted average texture of sandy loam or loam with clay ranging from 15 to 18 percent, silt from 15 to 20 percent, and sand from 40 to 70 percent with less than 50 percent fine sand or coarser. Content of rock fragments is typically less than 5 percent but ranges from 0 to 10 percent. These soils have fluctuating water tables during most of the period when not frozen. Mean annual soil temperature ranges from 47 degrees to 51 degrees F., and mean summer soil temperature ranges from 60 degrees to 68 degrees F. The Az horizon has hue of 5Y through 10YR, value of 6 or 7 dry and 4 or 5 moist, and chroma of 1.5 through 3. It is strongly to very strongly alkaline (pH 8.8 to 10.0). Typically this horizon has a granular or crumb structure. Exchangeable sodium percentage is normally about 20 percent but ranges from 15 to 30 percent. This horizon is soft to slightly hard, the B2g horizon has hue of 5Y through 10YR, value of 5 through 7 dry and 4 through 6 moist, and chroma of 1 through 3. It has many large prominent redox concentrations of contrasting color, but the base chroma of the horizon is 2 or less. This horizon is moderately or strongly alkaline (pH 8.0 to 8.0). It contains less than 1 to 3 millimhos conductivity and less than 5 percent exchangeable sodium.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Crowheart soils are on nearly level to gently sloping flood plains and are usually near the river channel. Slope gradients typically range from 0 to 4 percent. The soils formed in highly stratified flood plain alluvium derived principally from sedimentary rock. At the type location the average annual precipitation is 7 inches, with peak periods of precipitation in the spring and summer months. The soils have continuous water tables which keep them moist most of the year. The mean annual temperature is 43 degrees F., mean summer temperature is 64 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Glenton soils and the competing Bigwin soils. Glenton soils lack concentration of sodium in the upper horizons.
DRAINAGE AND PERMEABILITY: Poor and somewhat poorly drained; slow runoff; moderate and moderately slow permeability.
USE AND VEGETATION: These soils are used principally as native pasturelands. Principal native plants are cottonwood, willows, buffalo-berry, bluegrass, alkali sacaton, and inland saltgrass.
DISTRIBUTION AND EXTENT: Central portions of Wyoming. The series is of limited extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Fremont County (Riverton Irrigated Area), Wyoming, 1969.