LOCATION GRAFEN COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Ustic Haplocryolls
TYPICAL PEDON: Grafen extremely stony sandy loam - grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 10 inches; brown (10YR 5/2) extremely stony sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, very friable, nonsticky, nonplastic; 35 percent stones; neutral (pH 7.0); clear smooth boundary. (7 to 14 inches thick)
C1--10 to 30 inches; light brownish gray (10YR 6/2) extremely stony sandy loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, very friable, nonsticky, nonplastic; 70 percent stones; neutral (pH 7.); clear smooth boundary. (12 to 32 inches thick)
C2--30 to 60 inches; soft noncalcareous sandstone to interbedded loamstones with lenses of indurated sandstone.
TYPE LOCATION: Jackson County, Colorado; 1,300 feet north and 500 feet east of SW corner of Sec. 16, T. 10 N., R. 76 W.
RANGE IN CHARACTERISTICS: Mean annual soil temperature is about 42 degrees F. Base saturation ranges from 60 to 100 percent but is usually more than 90 percent. Depth to the paralithic contact ranges from 20 to 40 inches. The control section is usually sandy loam, but averages 5 to 18 percent clay, 5 to 40 percent silt, and 50 to 82 percent sand with more than 35 percent fine or coarser sand. Textures coarser than loamy very fine sand are excluded from the above range. Rock fragments range from 35 to 80 percent and are mainly more than 10 inches in diameter. In some pedons subhorizons redder than 7.5YR occur, but a major part of the control section above the bedrock has hue of 7.5YR or yellower.
The A horizon has hue of 5Y through 7.5YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 1 through 3. It ranges from slightly acid to mildly alkaline.
The C horizon has hue of 5Y through 7.5YR; subhorizons redder than 7.5YR occur in some pedons. It ranges from slightly acid to mildly alkaline.
COMPETING SERIES: These are the Brickel, Fairydell, Greyback, Handran, Maurice, Sebud, Supervisor, and Tiban series. Brickel and Supervisor soils have a lithic contact at depths of 20 to 40 inches. Fairydell, Handran, Greyback, Maurice, Sebud, and Tiban soils lack a paralithic contact above a depth of 40 inches.
GEOGRAPHIC SETTING: Grafen soils are on moderately to steeply sloping hills, ridges, and mountain sides. The soil formed in moderately thin noncalcareous, moderately coarse textured parent materials weathered from soft sandstone and loamstone. At the type location the average annual precipitation is 14 inches with peak periods of precipitation in the spring and early summer. Mean annual temperature is 38 degrees F. and mean summer temperature is 55 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the competing Handran soil.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; rapid permeability.
USE AND VEGETATION: These soils are used mainly as native pastureland. Native vegetation is sage, junegrass, and sheep fescue.
DISTRIBUTION AND EXTENT: High mountain valleys of north-central Colorado. The 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.