LOCATION DEWVILLE COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Ustic Argicryolls
TYPICAL PEDON: Dewville loam - grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 10 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure, weak subangular blocky in the lower portion; slightly hard, very friable; 5 percent gravel; neutral; clear smooth boundary. (6 to 14 inches thick)
B2--10 to 30 inches; brown (10YR 5/3) light sandy clay loam, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, very friable; few thin patchy clay films on vertical faces on peds; 5 percent gravel; neutral; clear wavy boundary. (8 to 30 inches thick)
C1ca--30 to 45 inches; grayish brown (10YR 5/2) sandy loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, very friable; 5 percent gravel; visible secondary calcium carbonate occurring as concretions, and in thin seams and streaks; moderately alkaline; diffuse wavy boundary. (10 to 20 inches thick)
C2ca--45 to 60 inches; pale brown (10YR 6/3) sandy loam, brown (10YR 5/3) moist; massive; slightly hard, very friable; 5 percent gravel; visible secondary calcium carbonate occurring mostly as concretions, and in thin seams and streaks; moderately alkaline.
TYPE LOCATION: Gunnison County, Colorado; 1 1/2 miles west of the town of Parlin, Colorado; Sec. 15, T. 49 N., R. 2 E.
RANGE IN CHARACTERISTICS: Thickness of the mollic epipedon ranges from 7 to 15 inches, depth to calcareous material ranges from 15 to 36 inches, thickness of the solum ranges from 15 to 40 inches. The organic carbon content of the mollic epipedon ranges from .7 to 2 percent and decreases uniformly with increasing depth. The soils are 80 to 100 percent base saturated. Rock fragments in the control section range from 0 to 15 percent by volume and are mainly gravel size. The control section is mainly loam or sandy clay loam grading to sandy loam with increasing depth. Clay ranges from 18 to 30 percent, silt from 5 to 30 percent, and sand from 45 to 75 percent with a major portion of the control section containing more than 35 percent fine or coarser sand. The solum ranges from slightly acid to mildly alkaline.
The A1 horizon has hue of 2.5Y or 10YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3. Usually the horizon has granular structure, but it is weak subangular blocky in the lower portion of some pedons. It is soft or slightly hard.
The B2 horizon has hue of 10YR or 7.5YR, value of 5 or 6 dry, 4 or 5 moist, and chroma of 3 or 4. Usually it has moderate subangular blocky structure, but it has weak prismatic structure in some pedons. This horizon has brighter chroma or redder hue than the overlying or underlying horizons, or has moderate structure overlying a continuous ca horizon.
The Cca horizon has hue of 2.5Y or 10YR. It ranges from pH 8.0 to 8.6, and has about 4 to 12 percent calcium carbonate equivalent.
COMPETING SERIES: These are the Auzqui, Babb, Bynum, Emerald, Promontory, Redcloud, Tampico, Teton, Thayne, Tilton, and Wrenman series. Auzqui soils have no continuous horizon of secondary calcium carbonate accumulation and lack a cambic horizon. Babb soils have a calcic horizon and generally have over 15 percent rock fragments throughout their control section. Bynum, Promontory, Teton, and Wrenman soils have bedrock at depths of less than 40 inches. Emerald and Tampico soils are noncalcareous throughout. Redcloud soils have 15 to 35 percent rock fragments throughout their control section and contain less than 35 percent fine and coarser sand. Thayne soils have loamy- skeletal substratums above depth of 40 inches and have more than 15 percent rock fragments throughout the control section. Tilton soils contain less than 35 percent fine and coarser sand and have finer textured C horizons with more than 18 percent clay to a depth of 40 inches or more.
GEOGRAPHIC SETTING: The Dewville soils are on moderately to steeply sloping upland alluvial fans and valley-filling side slopes. Slope gradients range from 2 to 20 or more percent. The soils formed in alluvial fan sediments derived principally from rhyolite or similar rock. At the type location the mean annual precipitation is approximately 20 inches with nearly equal distribution falling throughout the year. The average annual temperature is 38 degrees F, and the average July temperature is 56 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Redcloud and Tilton soils.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used principally as native pastureland. Native vegetation is mainly big sage, Arizona fescue, Indian ricegrass, mountain muhly, and mutton grass.
DISTRIBUTION AND EXTENT: Mountainous areas of western and central Colorado. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Gunnison County, Colorado, 1975.
REMARKS: Last updated by the state 1/75.