LOCATION KEELDAR CO+UTEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Aridic Calciustolls
TYPICAL PEDON: Keeldar gravelly sandy loam, grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 10 inches, grayish-brown (10YR 5/2) gravelly sandy loam, very dark grayish brown (10YR 3/2) when moist; moderate, fine, granular structure; soft, very friable; 15 percent gravel; calcareous; moderately alkaline; clear, smooth boundary. (8 to 20 inches thick)
AC--10 to 20 inches, grayish-brown (10YR 5/2) gravelly sandy loam, dark grayish brown (10YR 4/2) when moist; weak, medium, subangular blocky structure; slightly hard, very friable; 20 percent gravel; calcareous; moderately alkaline; gradual, smooth boundary. (7 to 20 inches thick)
C1ca--20 to 40 inches, light-gray (10YR 7/2) gravelly sandy loam, grayish brown (10YR 5/2) when moist; massive; slightly hard, very friable; 20 percent gravel; much visible secondary calcium carbonate occurring as concretions, in thin seams, streaks, and in finely divided marl-like forms; calcareous; moderately alkaline; gradual, wavy boundary. (10 to 20 inches thick)
C2ca--40 to 60 inches, light brownish-gray (10YR 6/2) gravelly sandy loam, dark grayish brown (10YR 4/2) when moist; slightly hard, very friable; 25 percent gravel; some visible calcium carbonate occurring as concretions, and in thin seams and streaks; calcareous; moderately alkaline.
TYPE LOCATION: Chaffee County, Colorado; 1,200 feet east of the northwest corner of Sec. 3, T. 49 N., R. 8 E.
RANGE IN CHARACTERISTICS: Depth to the calcic horizon ranges from 10 to 30 inches. The control section is normally gravelly sandy loam but clay averages 5 to 18 percent, silt 5 to 35 percent, and sand 5 to 85 percent. Rock fragments range from 15 to 35 percent by volume and are typically less than 3 inches in diameter but range up to 10 inches.
The A horizon has hue of 2.5Y through 7.5YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 1 through 3. It ranges from mildly through strongly alkaline. It is usually gravelly sandy loam with less than 18 percent clay in the fine earth fraction.
The C horizon has hue of 2.5Y through 7.5YR. This horizon ranges from moderately to very strongly alkaline and has 15 to 40 percent calcium carbonate equivalent of the fine earth fraction.
COMPETING SERIES: These are the Binna and St. Elmo series. Binna soils formed in stratified alluvium and they have a fine-loamy over sandy-skeletal control section. St. Elmo soils have a sandy-skeletal control section.
GEOGRAPHIC SETTING: The Keeldar soils are on alluvial fans, high terraces, or valley side slopes. Slope gradients range from 0 to 15 percent. The soils formed in alluvial parent materials derived from a variety of sources but usually containing a strong influence from sedimentary rock. At the type location the average annual precipitation is 12 inches, with peak periods of precipitation in the spring and summer. The mean annual temperature is 44 degrees F., and the mean summer temperature is 61 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing St. Elmo soils and the Ouray soils. Ouray soils lack calcic horizons.
DRAINAGE AND PERMEABILITY: Well-drained; slow run-off; rapid permeability.
USE AND VEGETATION: Used as native pastureland and as irrigated cropland. Native vegetation is mainly Junegrass, sand dropseed, blue grama, and needleandthread grass.
DISTRIBUTION AND EXTENT: Mountain valleys of central Colorado. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Chaffee County, Colorado, 1974.
REMARKS: Last updated by the state 8/74.