LOCATION CURABITH CO+WYEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Aridic Calciustolls
TYPICAL PEDON: Curabith loam - on a west facing slope of 5 percent on grassland at 5,300 feet elevation. (Colors are for dry soil unless otherwise noted.)
A--0 to 10 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak medium granular structure; soft, very friable; 5 percent channery fragments; strong effervescence; moderately alkaline (pH 8.2); abrupt smooth boundary. (7 to 10 inches thick)
Bk1--10 to 25 inches; very pale brown (10YR 7/3) very channery sandy loam, light yellowish brown (10YR 6/4) moist; massive; soft, very friable; 45 percent channery fragments, 15 percent flagstones; lime coatings on rock fragments; violent effervescence; strongly alkaline (pH 8.6); clear smooth boundary. (14 to 30 inches thick)
Bk2--25 to 42 inches; pink (7.5YR 7/4) channery sandy loam, strong brown (7.5YR 5/6) moist; massive; soft, very friable; 25 percent channery fragments, 5 percent flagstones; lime coatings on rock fragments; strong effervescence; strongly alkaline (pH 8.6); diffuse wavy boundary. (16 to 24 inches thick)
Bk3--42 to 60 inches; pink (7.5YR 7/3) very channery loamy sand, light brown (7.5YR 6/4) moist; massive; soft, very friable; 35 percent channery fragments, 35 percent flagstones; lime coatings on rock fragments; strong effervescence; strongly alkaline (pH 8.5).
TYPE LOCATION: Weld County, Colorado; about 20 miles east and 1 mile north of Hereford; 2,640 feet east and 500 feet south of the NW corner of Sec. 23, T. 12 N., R. 59 W. U.S.G.S. Bushnell SW quad.; Lat. 41 degrees, 00 minutes, 08 seconds N., and Long. 103 degrees, 56 minutes, 35 seconds W.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 7 to 10 inches thick. The mean annual soil temperature is 49 to 52 degrees F. The particle-size control section is commonly sandy loam with clay ranging from 8 to 18 percent, silt 10 to 30 percent, and sand 55 to 80 percent. Rock fragments are common in all horizons and average 35 to 65 percent in the particle-size control section.
The A horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3. Texture is loam or fine sandy loam. It is slightly alkaline or moderately alkaline.
The Bk horizons have hue of 7.5YR or 10YR, value of 5 through 8 dry, 4 through 7 moist, and chroma 2 through 6. Texture is commonly sandy loam, with loamy sand in lower horizons, modified yb rock fragments. They are moderately alkaline or strongly alkaline. The Bk1 has 10 to 35 percent calcium carbonate equivalent. Calcium carbonate equivalent decreases in lower horizons and ranges from about 5 to 30 percent.
COMPETING SERIES: These are the Ayon (NM), Hogadero (NM), Mextank (AZ), Modyon (NM), and Pena (NM) series. Ayon soils have rock fragments that are mostly larger than 10 inches in diameter, have 18 to 35 percent clay in the particle-size control section, and have a large component of basaltic mineral grains in the sand and silt fraction.
Hogadero soils have cemented horizons and have mean annual soil temperature of 52 to 57 degrees F.
Mextank soils have mean annual soil temperature of 54 to 56 degrees F., and have mollic surface layers of 10 to 20 inches.
Modyon soils are moderately deep over basalt bedrock.
Pena soils have a mollic epipedon 10 to 20 inches thick and are cobbly.
GEOGRAPHIC SETTING: Curabith soils are on shoulders and crest of upland ridges and hills, and on high plains. Slope ranges from 0 to 20 percent. The soils formed in calcareous, moderately coarse textured marine deposits. The annual precipitation ranges from 11 to 15 inches with peak periods of precipitations during the spring and summer. Elevation is 4,500 to 5,500 feet. The average annual temperature ranges from 46 to 50 degrees F. The frost-free period is 130 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ascalon, Bordeaux, Nunn, and Wormser soils. Ascalon, Nunn, and Wormser soils have an argillic horizon. Bordeaux soils lack a calcic horizon and contain less than 15 percent channery fragments, by volume, in all parts.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately rapid permeability.
USE AND VEGETATION: These soils are used primarily for native range. Native vegetation is mainly little bluestem, sideoats grama, blue and hairy grama, big bluestem, needleandthread, and prairie sandreed. Some areas are used for dry cropland.
DISTRIBUTION AND EXTENT: Northeastern Colorado. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Weld County (Northern Part), Colorado, 1980.
REMARKS: Diagnostic horizons and features recognized are: a mollic epipedon; a calcic horizon from 10 to 25 inches; more than 35 percent rock fragments in the texture control section; and a mesic temperature regime. Last updated by the state 6/95.