LOCATION DOMINSON CO+UTEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, frigid Aridic Haplustolls
TYPICAL PEDON: Dominson gravelly sandy loam - grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 12 inches; brown (10YR 5/3) gravelly sandy loam dark brown (10YR 3/3) moist; fine granular structure; soft, very friable; 20 percent gravel; noncalcareous; mildly alkaline (pH 7.6); diffuse wavy boundary. (7 to 15 inches thick)
IIC--12 to 60 inches; pale brown (10YR 6/3) very gravelly loamy sand, brown (10YR 5/3) moist; single grained; loose; calcareous; moderately alkaline (pH 8.2).
TYPE LOCATION: Chaffee County, Colorado; 1/4 mile east and 1/4 mile north of SW corner of Sec. 15, T. 15 S., R. 78 W.
RANGE IN CHARACTERISTICS: The mollic epipedon is 7 to 15 inches thick. Depth to calcareous material ranges from 0 to 39 inches. Continuous subhorizons of visible secondary carbonate do not occur above 40 inches, but some visible accumulation of calcium carbonate may occur inconsistently in the IIC horizon. Depth to very gravelly sand or loamy sand is less than 20 inches. Organic carbon content of the mollic epipedon ranges from .8 to 2.5 percent, decreases uniformly with depth, and reaches levels of less than .2 percent within 50 inches. The control section averages very gravelly loamy sand or sand. It contains 35 to 75 percent coarse fragments. Mean annual soil temperature is 32 to 46 degrees F, and mean summer soil temperature is 59 to 69 degrees F. The soil temperature at 20 inches is 41 degrees F. or higher for normally less than 230 days. Cumulative time the soil is moist in some part of the moisture control section and the soil temperature at 20 inches is 41 degrees F. or higher is approximately 40 to 115 days. The soils are moist in all parts of the moisture control section for less than 60 cumulative days during the 120 days following the winter solstice.
The A horizon has hue of 5Y through 7.5YR, value of 4.5 to 5.5 dry, 2 or 3 moist, and chroma of 2 or 3. It is neutral to moderately alkaline (pH 6.6 to 8.2 with 1:5 dilution unbuffered organic dye.) This horizon usually has granular or crumb structure, but is subangular blocky in some pedons. It is soft to slightly hard.
The C horizon has hue of 5Y through 7.5YR. It is neutral to strongly alkaline (pH 6.6 to pH 8.6 with 1:5 dilution unbuffered organic dye). This horizon has less than 1 to 14 percent calcium carbonate equivalent and amount and placement of calcium carbonate is erratic from pedon to pedon.
COMPETING SERIES: This is the Kassler series. Kassler soils are noncalcareous to depths of 40 inches or more and have hues redder than 5YR in the C horizons.
GEOGRAPHIC SETTING: The Dominson soils are on gently to moderately sloping old alluvial fans or terraces. Slopes usually range from 0 to about 6 percent but range up to 45 percent. The soils formed in thick coarse textured calcareous alluvial materials derived from mixed sources. At the type location the average annual precipitation is 14 inches with peak periods of precipitation occurring in the spring and early summer months. Mean annual temperature is 44 degrees F, and mean summer temperature is 59 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the San Isabel and St. Elmo soils. San Isabel soils have very gravelly sandy loam argillic horizons. St. Elmo soils have calcic horizons.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow runoff; very rapid permeability.
USE AND VEGETATION: These soils are used as native pastureland or for irrigated hay and grain crops. Native vegetation is blue grama, bluegrass, sand dropseed, yucca, and cactus.
DISTRIBUTION AND EXTENT: High mountain valleys of south-central Colorado. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Chaffee Lake Area, Colorado, 1971.
REMARKS: Last updated by the state 2/84.