LOCATION BOYLE CO+WYEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid, shallow Aridic Argiustolls
TYPICAL PEDON: Boyle gravelly sandy loam - grassland. (Colors are for dry soil unless otherwise noted.)
A--0 to 5 inches; brown (7.5YR 5/2) gravelly sandy loam, dark brown (7.5YR 3/2) moist; weak fine subangular blocks parting to moderate fine granular structure; soft, very friable; 15 percent pebbles; neutral; clear smooth boundary. (3 to 8 inches thick)
Bt1--5 to 10 inches; brown (7.5YR 5/3) gravelly sandy clay loam, dark brown (7.5YR 3/3) moist; moderate medium subangular blocky structure; very hard, firm; thin patchy clay films on peds; 25 percent pebbles; neutral; clear smooth boundary. (3 to 6 inches thick)
Bt2--10 to 13 inches; reddish brown (5YR 5/4) extremely gravelly sandy clay loam, dark reddish brown (5YR 3/4) moist; weak medium subangular blocky structure; very hard, friable; thin patchy clay films on peds; 70 percent pebbles; neutral; gradual wavy boundary. (3 to 5 inches thick)
Cr--13 to 20 inches; weathered granite.
TYPE LOCATION: Larimer County, Colorado; about 28 miles north and 22 miles west of Fort Collins; about 1,100 feet south of the state line and just west of Tie Siding road in Sec. 22, T. 12 N., R. 73 W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 42 through 46 degrees F.
Mean summer temperature: more than 59 degrees F.
Thickness of the mollic epipedon: 7 to 14 inches
Depth to the paralithic contact: 10 to 20 inches to weathered granite
The soil is noncalcareous and is slightly acid or neutral.
Rock fragments range from 15 to 80 percent by volume in individual horizons but average more than 35 percent in the Bt horizons and are mainly fine granitic gravel but includes 0 to 20 percent cobble. Some pedons have thin C horizons directly above the paralithic contact.
A horizon:
Hue: 5YR through 10YR
Value: 3 through 5 dry, 2 or 3 moist
Chroma: 1 through 3
Texture: gravelly sandy loam or gravelly loam
Bt horizon:
Hue: 2.5YR through 10YR
Value: 4 or 5 dry, 3 or 4 moist, and chroma of 2 through 4
Texture: typically gravelly to extremely gravelly sandy clay loam and has 18 to 35 percent clay in the fine earth fraction.
COMPETING SERIES: There are not competing series in this family.
GEOGRAPHIC SETTING:
Parent material: formed in coarse and moderately coarse textured parent materials weathered mainly from granite or gneiss
Landform: uplands and mountain hill slopes
Slope: 1 to 55 percent
Elevation: 6,000 to 8,500 feet
Average annual precipitation: 12 to 18 inches, most of which falls in the months of May through September
Average annual air temperature: 40 to 47 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Moen, Ratake, Trag, and Wetmore soils. Moen and Trag soils lack paralithic contacts above a depth of 20 inches and contain less than 35 percent rock fragments. Ratake soils lack argillic horizons. Wetmore soils have argillic horizons that are in the form of discontinuous lamellae.
DRAINAGE AND PERMEABILITY: Well drained or excessively drained; slow runoff; moderately and moderately rapid permeability.
USE AND VEGETATION: These soils are used mainly for native pasture and for recreational purposes. Native vegetation is mainly fringed sage, pussytoes (anteunaria), blue grama, bluebunch wheatgrass, fescues, junegrass, and mosses.
DISTRIBUTION AND EXTENT: Mountain areas of the front range in central Colorado, and adjacent areas in Wyoming. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Larimer County Area, Colorado, 1975.
REMARKS: Features include a mollic epipedon from 0 to 10 inches. An argillic horizon from 5 to 13 inches. A diagnostic paralithic contact at 13 inches.
Classification was changed from Aridic Argiborolls to superactive Aridic Argiustolls 2/99.
Taxonomic version: Eighth Edition, 1998.