LOCATION AFLEY              CO
Established Series
BWC/GB/TWH
7/98

AFLEY SERIES


The Afley series consists of moderately deep, well drained soils that formed in till from basalt and in residuum and colluvium derived from metamorphic and igneous rock. Afley soils are on mesa summits, alpine mountain slopes, and alpine basins. Slopes are 0 to 70 percent. The mean annual precipitation is about 35 inches and the mean annual temperature is about 32 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Typic Dystrocryepts

TYPICAL PEDON: Afley gravelly loam - on an alpine Slope. (Colors are for dry soil unless otherwise noted.)

A--0 to 7 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable, slightly sticky and nonplastic; 15 percent pebble, 5 percent cobble, 5 percent stone; moderately acid (pH 5.6); gradual wavy boundary. (5 to 10 inches thick)

Bw1--7 to 22 inches; yellowish brown (10YR 5/4) very stony loam, dark yellowish brown (10YR 3/4) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; 20 percent pebbles, 15 percent cobble, 15 percent stone; moderately acid (pH 5.6); gradual wavy boundary. (15 to 25 inches thick)

Bw2--22 to 30 inches; brown (7.5YR 5/4) extremely stony sandy loam, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; loose, very friable, nonsticky and nonplastic; 25 percent pebbles, 25 percent cobble, 25 percent stone; strongly acid (pH 5.2); clear irregular boundary. (0 to 10 inches thick)

R--30 inches; igneous bedrock.

TYPE LOCATION: Gunnison County, Colorado; on an old mining road 850 feet west of Paradise Divide, estimated to be in the NW 1/4 of the NE 1/4 of the NE 1/4 of Sec. 26, T. 12 S., R. 87 W. Latitude 38 degrees, 59 minutes, 20 seconds North; Longitude 107 degrees, 04 minutes, 00 seconds West .

RANGE IN CHARACTERISTICS:
Soil moisture regime: udic
Mean annual soil temperature: 29 to 38 degrees F.
Depth to lithic contact: 20 to 40 inches

A horizon
Hue: 7.5YR or 10YR
Value: 3 through 5 dry, 2 or 3 moist
Chroma: 1 through 3, dry or moist
Base saturation: 23 to 44 percent
Reaction: strongly acid or moderately acid

Bw horizon:
Hue: 7.5YR or 10YR
Value: 4 through 6 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Texture of the fine-earth fraction: loam or sandy loam
Rock fragment content : 35 to 80 percent, dominantly stone, and typically increases with depth
Clay content: 15 to 27 percent
Reaction: strongly acid or moderately acid

COMPETING SERIES: These are the Endlich, Henson, Ivywild, and Leighcan soils. In addition, the following may be competitors when their classification is updated: Bensley, Grenadier, Heterwa, Jeru, Klootch, Marsell, Nambe, Oatman, and Snotown.
Bensley soils - do not have a lithic contact above 40 inches
Endlich soils - do not have dark colored surface horizons greater than 5 inches thick
Grenadier soils - do not have a lithic contact above 40 inches
Henson soils - do not have a lithic contact above 40 inches
Heterwa soils - have combination E/Bw horizons
Ivywild soils - have a paralithic contact
Jeru soils - do not have a lithic contact above 40 inches
Klootch soils - have volcanic ash at the surface
Leighcan soils - do not have a lithic contact above 40 inches
Marsell soils - do not have a lithic contact above 40 inches
Nambe soils - do not have a lithic contact above 40 inches
Oatman soils - do not have a lithic contact above 40 inches
Snotown soils - have base saturation less than 15 percent and are bordering a xeric moisture regime (dry from late August through October)

GEOGRAPHIC SETTING: Afley soils are on mesa summits, alpine mountain slopes, and alpine basins. Slopes are 0 to 70 percent. The soil formed in till from basalt, and in residuum and colluvium from igneous rock and metamorphosed sedimentary rock. Elevation ranges from 10,000 to 12,500 feet. The mean annual precipitation ranges from 34 to 40 inches. The mean annual temperature ranges from 27 to 34 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Teewinot and Moran soils. Teewinot soils have a lithic contact at 7 to 20 inches. Moran soils are very deep.

DRAINAGE AND PERMEABILITY: Well drained; very rapid runoff; rapid and moderately rapid permeability.

USE AND VEGETATION: This soil is used for recreation and wildlife habitat. Native vegetation is kobresia, tufted hairgrass, alpine bluegrass, and arctic bluegrass.

DISTRIBUTION AND EXTENT: West central and southeastern Colorado. LRR E, MLRA 48A. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Grand Mesa-West Elk Soil Survey Area, Gunnison County, Colorado, 1993. The soil name is from an old mountain peak in the Crested Butte area of Colorado.

REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon: from 0 to 7 inches (A horizon)
Cambic horizon: from 7 to 30 inches (Bw1 and Bw2 horizons)
Particle-size control section: the zone from 10 to 30 inches (part of the Bw1 and the Bw2 horizon)
Lithic contact: at 30 inches (R layer)

This revision changes the subgroup classification from Typic Cryumbrepts to Typic Dystrocryepts, and adds the superactive CE activity class. It was determined that the A horizon was typically too thin for an umbric epipedon.

ADDITIONAL DATA:


National Cooperative Soil Survey
U.S.A.