LOCATION EMBARGO COEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic Ustic Argicryolls
TYPICAL PEDON: Embargo very stony loam - grassland. (Colors are for dry soil unless otherwise noted.)
A--0 to 7 inches; brown (7.5YR 4/2) very stony loam, dark brown (7.5YR 3/2) moist; moderate very fine granular and crumb structure; soft, very friable; 40 percent stones; neutral (pH 7.0); clear smooth boundary. (6 to 8 inches thick)
BA--7 to 12 inches; brown (7.5YR 4/2) very stony loam, dark brown (7.5YR 3/2) moist; moderate fine subangular blocky structure parting to moderate very fine granules; slightly hard, very friable; peds are hard; few thin glossy patches on faces of peds and discontinuous glossy coatings in pores; 40 percent stones; neutral (pH 7.0); clear smooth boundary. (3 to 6 inches thick)
Bt--12 to 30 inches; brown (7.5YR 5/2) extremely stony clay, brown (7.5YR 4/2) moist; moderate medium subangular blocky structure parting to strong fine and very fine subangular blocks; slightly hard, very friable, slightly sticky, plastic; peds are hard; thin continuous wax-like coatings on faces of peds and on the surfaces of coarse fragments; wax-like coatings in root channels and wax-like rims around openings to many soil pores; 65 percent stones; neutral (pH 7.2); gradual wavy boundary. (7 to 22 inches thick)
BC--30 to 34 inches; pinkish gray (7.5YR 6/2) extremely stony clay loam, brown (7.5YR 4/2) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky, plastic; peds are hard; a few thin glossy patches on faces of peds and discontinuous glossy coatings on some rock fragments; 70 percent stones; slightly alkaline (pH 7.4); clear wavy boundary.
R--34 inches; rhyolite bedrock.
TYPE LOCATION: Rio Grande County, Colorado; SW1/4 of Sec. 3, T. 37 N., R. 6 E.; Greenie Mountain Quadrangle; 37 degrees, 28 minutes, 40 seconds, north latitude; 106 degrees, 18 minutes, 28 seconds west longitude.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature is 39 to 41 degrees F.
Mean summer soil temperature is 44 to 46 degrees F.
Thickness of solum and depth to lithic contact: 20 to 40 inches.
Depth to the base of the argillic horizon ranges from 16 to 40 inches.
Reaction: slightly acid to moderately alkaline.
Rock fragment content in the particle-size control section: 35 to 75 percent.
Moisture regime: Udic bordering on ustic.
The A horizon:
Hue: 10YR or 7.5YR
Value: 3 through 5 dry, 2 or 3 moist
Chroma: 2 or 3.
The Bt horizon:
Hue: 10YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 through 4
Clay content: 35 to 60 percent
Rock fragment content: 35 to 75 percent, dominantly stones, but include gravel and cobble.
Textures of the fine earth fraction: clay loam, sandy clay, and clay.
Reaction: slightly acid to slightly alkaline
The BC or C horizons: (if present)
Hue: 10YR or 7.5YR
Value: 5 through 7 dry, 4 or 5 moist
Chroma: 2 or 3.
Clay content: 35 to 60 percent
Rock fragment content: 35 to 75 percent
Reaction: slightly acid to moderately alkaline
COMPETING SERIES: These are the
Evna (CO),
Passar (CO),
Redchief (MT),
Rooset (WY), and
Tellura (CO) series.
Evna, Passar, Redchief, Rooset, and Tellura soils lack bedrock above a depth of 40 inches.
GEOGRAPHIC SETTING:
Parent material: colluvium and residuum from basalt, rhyolite, breccia and tuff.
Landform: mountain slopes, plateaus, and ridges.
Slopes: 2 to 50 percent.
Elevation: 9,000 to 11,000 feet.
Mean annual precipitation is 16 to 26 inches with peak periods of precipitation in the summer and early fall months.
Mean annual temperature is about 34 to 42 degrees F., and mean summer temperature is about 43 to 45 degrees F.
Frost-free period is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fulcher and Seitz soils. Fulcher soils lack bedrock above a depth of 40 inches and have mollic epipedons thicker than 16 inches. Seitz soils lack bedrock above a depth of 40 inches, and have thick continuous E horizons and ochric epipedons.
DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; slow permeability.
USE AND VEGETATION: These soils are used principally for native pastureland. Native vegetation consists of Arizona fescue, mountain muhly, and junegrass.
DISTRIBUTION AND EXTENT: South-central Colorado; LRR E, MLRA 48A. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Rio Grande County, Colorado; 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: the zone from 0 to 12 inches. (A and BA horizons)
Argillic horizon: the zone from 12 to 30 inches. (Bt horizon)
Lithic contact: rhyolite bedrock at 34 inches.
Last updated 4/01.
Remarks: This series was previously classified as Clayey-skeletal, montmorillonitic Argic Cryoborolls prior to the Eighth Edition of Soil Taxonomy.