LOCATION DENCO UTEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Leptic Haplotorrerts
TYPICAL PEDON: Denco silty clay loam, on an east facing, convex-concave, 14 percent slope in rangeland at an elevation of 5,640 feet. (Colors are for dry soil unless otherwise noted.)
A--0 to 4 inches; reddish brown (5YR 5/4) silty clay loam, red (2.5YR 4/6) moist; weak medium platy structure parting to moderate very fine subangular blocky; slightly hard, friable, very sticky and very plastic; few medium and fine, common very fine roots; common medium and very fine vesicular pores; 1 centimeter wide cracks are predominantly filled with loose soil; slightly effervescent, carbonates are disseminated; moderately alkaline (pH 8.4); clear smooth boundary. (2 to 4 inches thick)
Bssy1--4 to 11 inches; reddish brown (5YR 5/4) silty clay, red (2.5YR 4/6) moist; moderate very coarse prismatic structure parting to moderate medium and fine subangular blocky; very hard, very firm, very sticky and very plastic; few fine, common very fine roots; common fine and very fine tubular pores; few nonintersecting slickensides and pressure faces; 1 centimeter wide cracks extending vertically through the horizon; few very fine gypsum masses; slightly effervescent, carbonates are disseminated; moderately alkaline (pH 8.4); clear smooth boundary. (4 to 9 inches thick)
Bssy2--11 to 29 inches; reddish brown (5YR 5/4) silty clay, red (2.5YR 4/6) moist; moderate very coarse prismatic structure parting to weak medium and coarse subangular blocky; very hard, very firm, very sticky and very plastic; few fine and very fine roots; few fine and very fine tubular pores; common nonintersecting slickensides and pressure faces; 1 centimeter wide vertical cracks in upper part of horizon; few very fine gypsum masses; slightly effervescent, carbonates are disseminated; moderately alkaline (pH 8.4); gradual wavy boundary. (6 to 18 inches thick)
CBy--29 to 37 inches; reddish brown (5YR 5/4) silty clay, yellowish red (5YR 4/6) moist; massive, residual thin and moderately thick bedded rock structure; very hard, very firm, very sticky and very plastic; few very fine roots; common very fine and fine interstitial pores; few fine gypsum veins and crystals; slightly effervescent, carbonates are disseminated; moderately alkaline (pH 8.2); gradual wavy boundary. (0 to 9 inches thick)
Cr--37 inches; weathered shale bedrock.
TYPE LOCATION: Uintah County, Utah; about 4.5 miles northeast of Red Wash; located about 1,050 feet north and 1,450 feet west of the southeast corner of sec. 4, T. 7 S., R. 24 E., SLBM; Dinosaur N.W., Utah USGS quad; lat. 40 degrees 13 minutes 03 seconds N. and long. 109 degrees 12 minutes 49 seconds W., NAD 27
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is affected by precipitation that falls evenly through the year with a slight increase in late summer and early fall. Part of the precipitation is lost to runoff and evaporation. Typic aridic moisture regime.
Mean annual soil temperature: 47 to 51 degrees F.
Depth to paralithic contact: 20 to 40 inches to weathered shale
Vertic features: vertical cracks, 1 to 1.5 centimeters wide, extend from the surface to a depth of 20 to 25 inches; few to common slickensides and pressure faces
Particle-size control section: 35 to 50 percent clay
A horizon:
Hue: 2.5YR to 7.5YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 4 to 6 dry or moist
Calcium carbonate equivalent: 3 to 15 percent
EC (mmhos/cm): 0 to 16
SAR: 0 to 20
Reaction: moderately alkaline or very strongly alkaline
Bssy and CBy horizons:
Hue: 2.5YR to 7.5YR
Value: 4 to 7 dry, 4 or 5 moist
Chroma: 2 to 6 dry or moist
Texture: silty clay, clay, silty clay loam, or clay loam
Calcium carbonate equivalent: 3 to 15 percent
EC (mmhos/cm): 0 to 8
SAR: 0 to 10
Gypsum: 1 to 5 percent
Reaction: moderately alkaline or strongly alkaline
COMPETING SERIES: This is the Monpark series. Monpark soils have mean annual soil temperatures greater than 51 degrees F., and have an ustic aridic soil moisture regime.
GEOGRAPHIC SETTING:
Parent material: slope alluvium and colluvium over residuum derived from shale
Landform: hillslopes
Slopes: 2 to 25 percent
Elevation: 5,100 to 6,000 feet
Mean annual air temperature: 45 to 49 degrees F.
Mean annual precipitation: 5 to 12 inches
Frost-free period: 110 to 140 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Abracon, Clapper, Gerst, Milok, Montwel, Shotnick, and Tipperary series.
Abracon, Clapper, and Milok soils occur on fan remnants and have calcic horizons.
Gerst soils occur on hillslopes and are shallow to shale.
Shotnick and Tipperary soils occur on fan remnants and benches and are very deep.
Montwel soils occur on hill backslopes and have a fine-loamy particle-size control section.
DRAINAGE AND PERMEABILITY: Well drained, high and very high runoff, slow permeability.
USE AND VEGETATION: The major uses are rangeland, wildlife habitat, and recreation. Potential native vegetation is shadscale, galleta, and bottlebrush squirreltail. These soils have been correlated to Desert Clay (Shadscale) - 034XY104UT, and Desert Shallow Clay (Mat Saltbush) - 034XY117UT range sites in Utah.
DISTRIBUTION AND EXTENT: Northeastern Utah. LRR D, MLRA 34. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Uintah County, Uintah Area Soil Survey, Utah. 1998. The name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 10 to 37 inches. (Bssy1, Bssy2, and Cby horizons)
Ochric epipedon: The zone from 0 to 4 inches. (A horizon)
Vertic features: Cracks 1 centimeter or more wide extending from the surface to 20 inches, and the presence of slickensides at a depth of 4 to 29 inches in depth (Bssy horizons). Lab sample 82T7254 results confirmed vertic potential.
Paralithic contact: The contact with weathered shale at 37 inches. (Cr horizon)
These soils are located in an area that range up to 12 inches of precipitation (typically an ustic aridic zone), but the interaction of soil conditions (i.e. high clay content) and moisture only allow desert community plants to predominate.
The cation exchange activity class was inferred from laboratory data in the Uintah Area Soil Survey.
The classification was changed from mixed Vertic Torriorthents to smectitic Leptic Haplotorrerts 1/99.
Taxonomic Version: Eighth Edition, 1998.