LOCATION SKEIN                   CO

Established Series
Rev. WSH/CSW/JWB
04/2011

SKEIN SERIES

The Skein series consists of shallow or very shallow, well drained soils that formed in colluvium, slope alluvium or residuum of interbedded sandstone and shale. Skein soils are on mesa tops, ridges, structural benches and high terraces with slopes of 1 to 65 percent. The mean annual precipitation is about 14 inches and the mean annual temperature is about 44 degrees F.

TAXONOMIC CLASS: Loamy, mixed, superactive, frigid Lithic Calciustepts

TYPICAL PEDON: Skein loam - pinyon juniper woodland. (Colors are for dry soil unless otherwise noted.)

A--0 to 6 inches; reddish brown (5YR 4/4) loam, dark reddish brown (5YR 3/4) moist; weak fine granular structure; slightly hard, very friable, slightly sticky, strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (3 to 6 inches thick)

Bk1--6 to 13 inches; reddish brown (5YR 5/3) loam, dark reddish gray (5YR 4/2) moist; moderate medium subangular blocky structure; hard, very friable, slightly sticky, and slightly plastic; 20 percent calcium carbonate, disseminated; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (3 to 7 inches thick)

Bk2--13 to 19 inches; white (5YR 8/1) very gravelly loam, pinkish white (5YR 8/2) moist; massive; hard, very friable; 35 percent gravel and 15 percent cobbles; 43 percent calcium carbonate; lime disseminated throughout; violently effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (0 to 8 inches thick)

2R--19 to 23 inches; hard lime coated sandstone.

TYPE LOCATION: Montrose County, Colorado; about 5 miles east and 4 miles north of Uravan, Colorado, and 500 feet east and 1,200 feet south of the northwest corner of Sec. 9, T. 48 N., R. 16 W; Atkinson Creek USGS quad; latitude 38 degrees 25 minutes 56 seconds N. long. 108 degrees 38 minutes 47 seconds W., NAD 27.

RANGE IN CHARACTERISTICS:
The moisture control section is usually moist in some part during summer and early fall, and intermittently dry in late fall; ustic moisture regime bordering on Aridic.
Mean annual soil temperature ranges from 40 to 47 degrees F.
Mean summer soil temperature ranges from 59 to 64 degrees F.
Depth to the calcic horizon: 3 to 12 inches
Depth to the lithic contact: 8 to 20 inches

Particle-size control section:
Clay content: 18 to 27 percent
Rock fragments: 5 to 35 percent
A horizon:
Hue: 5YR or 7.5YR
Value: 4 or 6 dry, 3 or 4 moist
Chroma: 2 through 4.
Reaction: slightly alkaline or moderately alkaline.

Bk1 horizon:
Hue: 5YR or 7.5YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 through 4.
Calcium carbonate equivalent: 10 to 25 percent
Reaction: slightly alkaline or moderately alkaline.

Bk2 horizon:
Hue: 5YR or 7.5YR
Value: 6 through 8 dry, 4 through 6 moist
Chroma: 0 through 4.
Textures: loam, gravelly loam, or very gravelly loam
Reaction: moderately alkaline or strongly alkaline.
Calcium carbonate equivalent: 15 to 43 percent or less than 30 percent on a weighted basis.

COMPETING SERIES: There are no competing series. The closely related Cedarknoll, Culebra, Hackling, Rencot, Rentsac and Schoonover series have more than 35 percent coarse fragments in the particle-size control section.

GEOGRAPHIC SETTING: Skein soils are on mesa tops, ridges, structural benches and high terraces. Slopes range from 1 to 65 percent. The soil formed in colluvial remnants, slope alluvium or residuum derived dominantly from interbedded sandstone and shale. Skein soils are in a climatic setting that receives the annual precipitation in an evenly distributed pattern throughout the year with over 50 percent received as snow. Elevations range from 6,200 to 8,200 feet. Mean annual precipitation ranges from 12 to 16 inches. Precipitation Pattern: Wettest months are July to October and driest months are December and June. Mean annual temperature is 42 to 46 degrees F. The frost-free season is 85 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Callan, Gurley, and Radersburg soils. Callan soils lack bedrock above 40 inches. Gurley soils have bedrock at 20 to 40 inches. Radersburg soils lack bedrock above 40 inches and have more than 35 percent rock fragments in the particle-size control section.

DRAINAGE AND PERMEABILITY: Well drained; slow or medium runoff; moderate permeability.

USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. The native vegetation is mainly pinyon pine and Utah juniper with an understory of Indian ricegrass, western wheatgrass, and black sagebrush.

DISTRIBUTION AND EXTENT: Southwestern Colorado, central Utah and possibly adjacent areas in New Mexico. LRR D; MLRA 34; moderate extent.

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

SERIES ESTABLISHED: San Miguel County (San Miguel Area), Colorado, 1987.

REMARKS:

Series control section: The zone from 0 to 19 inches.
Particle-size control section; the zone from 10 to 19 inches.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: the zone from the surface to 6 inches (A horizon).
Calcic horizon: the zone from 6 to 19 inches (Bk1 and Bk2 horizons).
Lithic contact: hard lime coated sandstone at 19 inches (2R horizon).Last updated by the state 2/99.

Taxonomic Version: Classified according to Keys to Soil Taxonomy, Eleventh Edition, 2010.

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National Cooperative Soil Survey
U.S.A.