LOCATION BLEVINTON COEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Pachic Palecryolls
TYPICAL PEDON: Blevinton sandy loam - grassland. (Colors are for dry soil unless otherwise noted.)
A11--0 to 8 inches; dark grayish brown (10YR 4/2) sandy loam, very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, friable, nonsticky, nonplastic; neutral (pH 6.8); gradual smooth boundary. (4 to 10 inches thick)
A12--8 to 20 inches; dark grayish brown (10YR 4/2) light fine sandy loam, very dark brown (10YR 2/2) moist; weak coarse subangular blocky structure that parts to fine granules; slightly hard, very friable, nonsticky, nonplastic; neutral (pH 6.8); gradual smooth boundary. (4 to 20 inches thick)
A3--20 to 30 inches; brown (10YR 5/3) light fine sandy loam, dark brown (10YR 4/3) moist; weak coarse subangular blocky structure that parts to fine granules; slightly hard, very friable, nonsticky, nonplastic; neutral (pH 7.0); gradual smooth boundary. (0 to 16 inches thick)
B2t--30 to 48 inches; brown (10YR 5/3) fine sandy loam, dark brown (10YR 4/3) moist; weak very coarse prismatic structure that parts to coarse subangular blocks; slightly hard, very friable, nonsticky, nonplastic; thin glossy coatings on some faces of peds, in root channels and pores; thin wax-like bridges between sand grains; neutral (pH 7.0); gradual smooth boundary. (8 to 24 inches thick)
C--48 to 60 inches; brown (10YR 5/3) fine sandy loam, dark brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsticky, nonplastic; neutral (pH 7.2).
TYPE LOCATION: Jackson County, Colorado; approximately 2,500 feet east and 500 feet south of W 1/4 corner of Sec. 36, T. 7 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. Thickness of the mollic epipedon ranges from 13 to 20 inches and depth to the top of the argillic horizon ranges from 24 to 40 inches. Depth to uniformly calcareous material ranges from 50 to more than 60 inches. Base saturation ranges from 60 to 100 percent. Depth to the base of the argillic horizon ranges from 36 to more than 60 inches. The major part of the solum and C horizon above a depth of 60 inches has hue of 7.5 YR or yellower. Rock fragments range from 0 to 35 percent by volume in a major part of the solum and C horizon above a depth of 60 inches and are mainly 1/4 to 10 inches in diameter. These soils occur in concave areas and receive additional water during periods of spring runoff, and are dry in some part of the moisture control section for some time in most years.
The A horizon has hue of 5Y through 7.5YR, value of 3 through 5 dry, 2 or 3 moist, and chroma of 1 through 3. It ranges from slightly acid to mildly alkaline.
The B2t horizon has hue of 5Y through 7.5YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 1 through 6. It is typically sandy loam but averages 8 to 18 percent clay, 5 to 40 percent silt, and 50 to 80 percent sand with more than 35 percent fine or coarser sand. It ranges from slightly acid to mildly alkaline.
The C horizon has hue of 5Y through 7.5YR. It is typically sandy loam of less than 18 percent clay and more than 35 percent fine or coarser sand. This horizon ranges from slightly acid to mildly alkaline.
COMPETING SERIES: These are the Norway Flat and Osha series. Norway Flat and Osha soils have more than 35 percent rock fragments.
GEOGRAPHIC SETTING: The Blevinton soils are on gently to moderately sloping concave alluvial fans and small drainageways where winter snows accumulate and stay in the early spring. Slopes typically range from 0 to about 12 percent. The soil formed in thick, noncalcareous, alluvial fan materials derived from sedimentary bedrock. At the type location the average annual precipitation is 18 inches with peak periods of precipitation in the spring and early summer. Soil moisture supplies are substantially increased by snow accumulations. Mean annual temperature is 38 degrees F and mean summer temperature is 55 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bangston and Tiagos soils. Bangston soils are sand or loamy sand in the 10- to 40-inch section and lack an argillic horizon. Tiagos soils have the upper boundary of the argillic horizon above a depth of 24 inches.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately rapid permeability.
USE AND VEGETATION: Used principally as native pastureland. Native vegetation is nodding bromegrass and Idaho fescue.
DISTRIBUTION AND EXTENT: High mountain valleys of 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.