LOCATION POLYCHROME         UT+CO
Established Series
Rev. RJL/GWL/AP/SSP
09/1999

POLYCHROME SERIES


The Polychrome series consists of moderately deep, well drained soils that formed in slope alluvium and colluvium over residuum derived from sandstone and shale. Polychrome soils are on hills and scarps. Slopes range from 25 to 75 percent. Mean annual precipitation is about 10 inches and the mean annual temperature is about 47 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, calcareous, mesic Ustic Torriorthents

TYPICAL PEDON: Polychrome very channery loam, on an east facing, convex, 70 percent slope in rangeland at an elevation of 5,700 feet. (Colors are for dry soil unless otherwise noted.)

The surface is covered by 30 percent channers, 5 percent flagstones, and 5 percent stones.

A--0 to 3 inches; yellowish red (5YR 5/6) very channery loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure parting to weak very fine and fine subangular blocky; hard, friable, slightly sticky and nonplastic; few very fine, fine, medium, and coarse roots; many very fine and fine, common medium tubular pores; 10 percent gravel, 25 percent channers; slightly effervescent; 3 percent calcium carbonate equivalent; calcium carbonate disseminated; moderately alkaline (pH 8.2); abrupt wavy boundary. (1 to 4 inches thick)

Cy1--3 to 16 inches; reddish yellow (5YR 6/6) very channery loam, yellowish red (5YR 4/6) moist; weak very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; few very fine, fine, medium, and coarse roots; few very fine tubular pores; 30 percent channers, 5 percent flagstones, 10 percent stones; few fine irregular shaped soft masses of gypsum; very slightly effervescent; 2 percent calcium carbonate equivalent; calcium carbonate disseminated; moderately alkaline (pH 8.0); gradual wavy boundary. (Combined thickness of C horizons is 16 to 39 inches)

Cy2--16 to 23 inches; light red (2.5YR 6/6) extremely channery loam, red (2.5YR 4/6) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; many very fine, common fine, few medium roots; few very fine tubular pores; 40 percent channers, 20 percent flagstones, 10 percent stones; many very fine irregular shaped soft masses of gypsum; very slightly effervescent; 1 percent calcium carbonate equivalent; calcium carbonate disseminated; moderately alkaline (pH 8.0); gradual irregular boundary.

Cy3--23 to 38 inches; light red (2.5YR 6/6) very stony loam, dark red (2.5YR 3/6) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; many very fine, few fine and medium roots; few very fine tubular pores; 10 percent channers, 10 percent flagstones, 20 percent stones; many fine and medium irregular shaped soft masses of gypsum; very slightly effervescent; 1 percent calcium carbonate equivalent; calcium carbonate disseminated; moderately alkaline (pH 8.0); abrupt smooth boundary.

Cr--38 inches; weathered fine grained sandstone with irregular fractures about 6 inches apart; material will break out in gravel to flagstones size fragments with a Mohs scale hardness of about 2; roots are limited to fractured areas; excavation difficulty is high.

TYPE LOCATION: Uintah County, Utah; about 3.5 miles northeast of Island in White Sage Flats; located about 1,700 feet south and 1,800 feet west of the northeast corner of sec. 16, T. 3 S., R. 25 E., SLBM; Jones Hole, Utah-Colo. USGS quad; lat. 40 degrees 33 minutes 42 seconds N. and long. 109 degrees 6 minutes 48 seconds W., NAD 27

RANGE IN CHARACTERISTICS:
Soil moisture regime:
The SMCS is affected by precipitation that falls evenly with a slight increase in the late summer and fall. Aridic moisture regime bordering on ustic.
Mean annual soil temperature: 47 to 51 degrees F.
Surface rock fragments: channers, flagstones, and stones from sandstone and shale
Particle-size control section: 18 to 27 percent clay
Depth to paralithic contact: 20 to 40 inches to sandstone and shale

A horizon:
Hue: 5YR to 10YR
Value: 5 to 7 dry, 4 or 5 moist
Chroma: 3 to 6
Texture: very gravelly fine sandy loam, very channery loam
Rock fragments: 35 to 60 percent gravel, channers, flagstones, and stones from sandstone and shale
Calcium carbonate equivalent: 1 to 15 percent
EC (mmhos/cm): 2 to 4
Gypsum: 1 to 3 percent
Reaction: moderately alkaline or strongly alkaline

Cy horizon:
Hue: 2.5YR to 5YR
Value: 5 to 8 dry, 3 to 7 moist
Chroma: 2 to 6
Texture: loam, silt loam, sandy loam
Rock fragments: 35 to 75 percent gravel, channers, flagstones, and stones from sandstone and shale
Calcium carbonate equivalent: 1 to 15 percent
EC (mmhos/cm): 2 to 16
Gypsum: 1 to 10 percent
Reaction: moderately alkaline or strongly alkaline

COMPETING SERIES: These are the Chalkcliff and Notlic series. Potential series not yet updated to the Seventh Edition, 1996 are the Chilton, Happle, and Nihill soils.
Chalkcliff, Chilton, Happle, Nihill, and Notlic soils are very deep.

GEOGRAPHIC SETTING: Polychrome soils.
Parent material: slope alluvium and colluvium over residuum derived from sandstone and shale
Landform: hills and scarps.
Slopes: 25 to 75 percent
Elevation: 5,000 to 6,800 feet
Mean annual air temperature: 44 to 49 degrees F.
Mean annual precipitation: 8 to 12 inches.
Frost-free period: 110 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Milok, Paradox, and Yarts series.
Milok soils are on more stable landforms and have calcic horizons.
Paradox and Yarts soils are very deep and have less than 15 percent rock fragments in the PSCS.

DRAINAGE AND PERMEABILITY: Well drained, high runoff, moderate permeability.

USE AND VEGETATION: These soils are used principally for rangeland, wildlife habitat, and recreation. Potential vegetation consists of Utah juniper, pinyon, Salina wildrye, Wyoming big sagebrush, and Indian ricegrass. These soils have been correlated to the Semidesert Gravelly Loam (Wyoming Big Sagebrush) - 034XY205UT range site at the type location in Utah.

DISTRIBUTION AND EXTENT: Northeastern Utah and northwestern Colorado. LRR D, MLRA 34. This series is of small extent.

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

SERIES ESTABLISHED: Uintah County (Dinosaur National Monument Area) Utah, 1997. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: The zone from the surface to a depth of 3 inches. (A horizon)

The parent material is varicolored interbedded sandstone and shale, which feature accounts for the wide range of colors for this series.

The CEC activity class was inferred from laboratory data in the Uintah Area Soil Survey.

Taxonomy Version: Eighth Edition, 1998.


National Cooperative Soil Survey
U.S.A.