LOCATION CARLSTROM COEstablished Series
TAXONOMIC CLASS: Fine, smectitic Ustic Haplocryepts
TYPICAL PEDON: Carlstrom clay - grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 3 inches; brown (10YR 5/3) clay, brown (10YR 4/3) moist; moderate fine granular structure; soft, very friable, sticky, plastic; slightly alkaline (pH 7.6); clear smooth boundary. (2 to 8 inches thick)
AC--3 to 7 inches; brown (10YR 5/3) clay, brown (10YR 4/3) moist; weak coarse angular blocky structure that parts to medium angular blocks; slightly hard, very friable, sticky, plastic; peds are extremely hard, very firm; slightly alkaline (pH 7.6); gradual wavy boundary. (0 to 6 inches thick)
C1--7 to 26 inches; pale brown (10YR 6/3) clay, brown (10YR 5/3) moist; massive; extremely hard, very firm, sticky, plastic; slightly alkaline (pH 7.6); gradual wavy boundary. (6 to 37 inches thick)
C2--26 to 40 inches; shale.
TYPE LOCATION: Jackson County, Colorado; approximately 1,200 feet west and 1,050 feet north of center of Sec. 23, T. 9 N., R. 79 W.
RANGE IN CHARACTERISTICS: Mean annual soil temperature is about 42 degrees F and mean summer soil temperature is about 56 degrees F. These soils are noncalcareous throughout except that very thin, discontinuous, weakly calcareous subhorizons occur immediately above the shale in some pedons. Depth to the paralithic contact ranges from 20 to 40 inches. The control section is usually heavy clay loam or light clay but averages 35 to 60 percent clay, 5 to 50 percent silt, and 15 to 55 percent sand with more than 15 percent fine or coarser sand. Rock fragments range from 0 to 15 percent and are mainly 1/4 to 10 inches in diameter.
The A horizon has hue of 5Y through 7.5YR, value of 5 through 7 dry, 3 through 6 moist, and chroma of 1 through 4. It ranges from slightly acid to slightly alkaline.
The C horizon has hue of 5Y through 7.5YR but subhorizons redder than 75YR occur in some pedons. It ranges from slightly acid to moderately alkaline.
COMPETING SERIES: These are the Borean, Bundyman, and Crespin series. Borean and Crespin soils lack a paralithic contact above a depth of 40 inches. Bundyman soils have a cambic horizon and a Cca horizon.
GEOGRAPHIC SETTING: Carlstrom soils are on gently to steeply sloping hills, ridges, and mountainsides. Slopes typically range from 2 to about 60 percent. The soil formed in moderately thin noncalcareous moderately fine to fine textured materials weathered from sedimentary rocks. At the type location the average annual precipitation is 10 inches with peak periods of precipitation in the spring and early summer. Mean annual temperature is 38 degrees F and mean summer temperature is 56 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Bundyman and Crespin soils.
DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; slow to very slow permeability.
USE AND VEGETATION: These soils are used principally as grazing land. Native vegetation is sage, bluebunch wheatgrass, junegrass, fescue, and rabbitbrush.
DISTRIBUTION AND EXTENT: This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jackson County, Colorado, 1973.
REMARKS: Last updated by the state 10/73.
The original concept of this series when correlated and established in 1973 was a cryic temperature regime and an aridic moisture regime.