LOCATION CHALKCREEK WYEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Vitrandic Haplocambids
TYPICAL PEDON: Chalkcreek loam-rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; brown (10YR 5/3) loam, dark brown (10YR 4/3) moist; moderate fine granular structure; soft, friable, sticky and plastic; many fine roots; strongly effervescent, carbonates disseminated; moderately alkaline (pH 8.0); clear wavy boundary. (3 to 6 inches thick)
Bw--4 to 11 inches; brown (10YR 5/3) loam, dark brown (10YR 4/3) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; hard, firm, sticky and plastic; common fine roots; strongly effervescent, carbonates disseminated; moderately alkaline (pH 8.0); gradual wavy boundary. (6 to 10 inches thick)
C--11 to 60 inches; pale brown (10YR 6/3) loam, brown (10YR 5/3) moist; massive; very hard, firm, sticky and plastic; strongly effervescent, carbonates disseminated, moderately alkaline (pH 8.0).
TYPE LOCATION: Natrona County, Wyoming; Sheep Creek Quadrangle; 500 feet west and 2,000 feet south of the NE corner of sec. 4, T. 29 N., R. 79 W.
RANGE IN CHARACTERISTICS: Depth to the base of the cambic horizon ranges from 10 to 15 inches. The mean annual soil temperature is 44 to 47 degrees F., and the mean summer soil temperature is 59 to 64 degrees F. The particle-size control section is loam or clay loam with 20 to 30 percent clay and less than 15 percent fine or coarser sand. Very fine sand ranges from 30 to 45 percent and contains a high percentage of glass shards. Rock fragments are absent except for an isolated pebble in some pedons.
The A horizon has hue of 10YR or 2.5Y, value of 4 or 5 dry, 3 or 4 moist, and chroma of 2 or 3. It is mildly or moderately alkaline.
The Bw horizon has hue of 10YR or 2.5Y, value of 5 or 6 dry, 4 or 5 moist, and chroma of 2 or 3. It is loam or clay loam. It commonly is moderately alkaline but is mildly alkaline in pockets that are noncalcareous in some pedons.
The C horizon has hue of 10YR or 2.5Y, value of 6 through 8 dry, 5 or 6 moist, and chroma of 2 or 3. It is loam or clay loam. EC is less than 2 mmhos. Carbonates are disseminated with only a few soft pedogenetic accumulations in some pedons.
COMPETING SERIES: These are the Alona, Cambeth, Lonna, and Rahworth series. Alona soils are very strongly alkaline. Cambeth and Lonna soils have silt loam and silty clay loam textures and lack the glass shards. Rahworth soils lack the glass shards and have variegated C horizons.
GEOGRAPHIC SETTING: Chalkcreek soils are on terraces, footslopes, and alluvial fans. Slopes range from 0 to 12 percent. They formed in alluvium derived dominantly from tuffaceous siltstone. Elevation is 6,000 to 7,100 feet. The mean annual precipitation is 10 to 14 inches, the mean annual temperature is 39 to 42 degrees F., and the frost-free season is 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bateson, Cragosen, and Whiteriver soils. Bateson soils are fine-loamy and have an argillic horizon. Cragosen soils are loamy-skeletal and have bedrock at less than 20 inches. Whiteriver soils are fine and have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium or rapid runoff; moderately slow permeability.
USE AND VEGETATION: Chalkcreek soils are used mainly for livestock grazing and wildlife habitat. Native vegetation is mainly western wheatgrass, needleandthread, threadleaf sedge, and big sagebrush.
DISTRIBUTION AND EXTENT: Central Wyoming. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Natrona County, Wyoming; 1985.