LOCATION SUNSHINE COEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic Alfic Argicryolls
TYPICAL PEDON: Sunshine loam - grassland. (Colors are for dry soil unless otherwise noted.)
A1--O to 11 inches; very dark gray (7.5YR 3/1) loam, black (1OYR 2/1) moist; moderate medium granular structure; soft, very friable; 10 percent stones; neutral; clear smooth boundary. (7 to 12 inches thick)
A2--11 to 15 inches; pinkish gray (7.5YR 7/2) loam, brown (7.5YR 5/2) moist; weak thin platy structure that parts to moderate fine granules; soft, very friable; 15 percent stones; neutral; gradual wavy boundary. (3 to 6 inches thick)
A&B--15 to 21 inches; mixed pinkish gray (7.5YR 7/2) and brown (7.5YR 5/4) very stony loam, brown (7.5YR 5/2) and dark brown (7.5YR 4/4) moist; weak medium subangular blocky structure; slightly hard, very friable; this horizon consists of clayey material like that of the underlying horizon imbedded in a light colored matrix like that of the overlying horizon; 50 percent stones; neutral; gradual wavy boundary. (4 to 7 inches thick)
B2--21 to 36 inches; brown (7.5YR 5/4) very stony light clay, dark brown (7.5YR 4/4) moist; moderate medium angular blocky structure; very hard, friable; thin continuous clay films; 60 to 70 percent stones; neutral; gradual wavy boundary. (7 to 20 inches thick)
IIC--36 to 60 inches; loose overlapping rhyolite flagstones with interstices 1 to 2 inches between the rocks not filled with fine textured material.
TYPE LOCATION: Saguache County, Colorado; NW1/4 Sec. 17, T. 45 N., R. 2 E.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 7 to 15 inches thick. Thickness of solum and depth to fragmental substratums range from 20 to 40 inches. These soils are slightly acid or neutral throughout. Organic carbon ranges from .7 to 3 percent in the mollic epipedon and decreases uniformly with increasing depth in the profile. The soil is 80 to 100 percent base saturated, but there is no visible secondary calcium carbonate accumulation. Rock fragments range from 35 to 80 and are mainly stones more than 10 inches in diameter. The average annual soil temperature is 38 degrees F. and the average annual summer soil temperature is 52 degrees F., without an 0 horizon.
The A1 horizon has hue of 10YR or 7.5YR, value of 3 through 5 dry, 2 or 3 moist, and chroma of neutral through 2. It is soft or slightly hard. Typically, this horizon has a granular or crumb structure but it has subangular blocky structure in some pedons.
The A2 horizon has hue of 10YR or 7.5YR, value of 6 through 8 dry, 4 through 6 moist, and chroma of 2 through 4. Typically, it has weak platy structure, but it has subangular blocky structure in some pedons. This horizon is soft or slightly hard. The B2t horizon has hue of 7.5YR or 5YR, value of 5 or 6 dry, 4 or 5 moist, and chroma of 2 through 5. It is typically light clay or heavy clay loam but the matrix material ranges from 35 to 50 percent clay. Typically, this horizon has subangular blocky structure but it has weak prismatic structure in some pedons.
COMPETING SERIES: This is the Callings series. Callings soils have no fragmental substratum above depth of 40 inches.
GEOGRAPHIC SETTING: Sunshine soils are on moderate to steeply rolling mesa tops and valley side slopes. Slope gradient ranges from 2 to 30 or more percent. The soils formed in very stony sediments weathered from highly fractured rhyolite or rhyolitic tuff. At the type location the average annual precipitation is 20 inches and peak periods of precipitation occur during the spring and summer.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cebolia, Powderhorn, and Youman soils, all of which have less than 35 percent rock fragments in the control section.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; slow permeability.
USE AND VEGETATION: These soils are used principally as native pastureland. Native vegetation is mainly Thurber fescue, nodding brome, mountain bluegrass, and big sage.
DISTRIBUTION AND EXTENT: The high mountain areas of central Colorado. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Saguache County, Colorado 1974.
REMARKS: OSED scanned by NSSQA and cleaned up by Colorado. Last revised by state on 8/74.