LOCATION SCHOONOVER CO+UTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Lithic Calciustepts
TYPICAL PEDON: Schoonover, on a west facing, concave, 5 percent slope in rangeland at an elevation of 7,700 feet. (Colors are for dry soil unless otherwise noted.) When described on September 15, 1994 the soil was dry throughout.
The surface is covered by 30 percent gravel and 20 percent limestone channers.
A--0 to 3 inches; brown (7.5YR 4/4) very gravelly loam, brown (7.5YR 4/3) moist; weak medium and coarse subangular blocky structure parting to weak medium granular; soft, very friable, slightly sticky and slightly plastic; common fine roots; few fine vesicular and tubular pores; 20 percent gravel, 12 percent channers; 5 percent stones; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (2 to 4 inches thick)
Bk1--3 to 8 inches; brown (7.5YR 5/4) very gravelly loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure parting to weak medium granular; soft, very friable, slightly sticky and slightly plastic; common very fine roots; few fine vesicular and tubular pores; 20 percent gravel, 12 percent channers, 5 percent stones; calcium carbonate disseminated and in few rounded soft masses; violently effervescent; 15 percent calcium carbonate equivalent; moderately alkaline (pH 8.4); abrupt wavy boundary. (0 to 8 inches thick)
Bk2--8 to 11 inches; light brown (7.5YR 6/4) very gravelly loam, brown (7.5YR 4/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, sticky and plastic; few fine roots; few fine vesicular and tubular pores; 25 percent gravel, 10 percent channers, 5 percent stones; common distinct discontinuous calcium carbonate coats on rock fragments; common rounded soft masses of calcium carbonate throughout; violently effervescent; 25 percent calcium carbonate equivalent; strongly alkaline (pH 8.6); abrupt irregular boundary. (4 to 8 inches thick)
R--11 inches; hard limestone bedrock.
TYPE LOCATION: Moffat County, Colorado; located about 2,400 feet north and 400 feet east of the southeast corner of sec. 32, T. 8 N., R. 103 W.; Jones Hole USGS quad; lat. 40 degrees 36 minutes 8 seconds N. and long. 109 degrees 0 minutes 14 seconds W., NAD 1927
RANGE IN CHARACTERISTICS:
Soil moisture regime: Ustic moisture regime bordering on aridic.
Mean annual soil temperature: 42 to 46 degrees F.
Mean annual summer soil temperature: 63 to 68 degrees F.
Surface rock fragments: 5 to 15 percent limestone gravel, 5 to 30 percent limestone channers.
Particle-size control section: 18 to 27 percent clay
Depth to lithic contact: 10 to 20 inches to limestone
Depth to calcic horizon: 6 to 9 inches
Depth to visible secondary calcium carbonate: 6 to 9 inches
A horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 2 to 4, dry or moist
Rock fragments: mostly limestone with some sandstone; 35 to 60 percent total rock fragments; 20 to 40 percent gravel; 10 to 25 percent channers; 0 to 10 percent stones.
Calcium carbonate equivalent: 5 to 10 percent
EC (mmhos/cm): 0 to 2
Reaction: slightly alkaline or moderately alkaline
Bk1 horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 2 to 4, dry or moist
Rock fragments: mostly limestone with some sandstone; 35 to 75 percent total rock fragments; 20 to 40 percent gravel; 10 to 25 percent channers; 0 to 10 percent stones.
Calcium carbonate equivalent: 10 to 20 percent
EC (mmhos/cm): 0 to 2
Reaction: moderately alkaline or strongly alkaline
Bk2 horizon:
Hue: 7.5YR or 10YR
Value: 5 to 7 dry, 3 to 5 moist
Chroma: 2 to 4, dry or moist
Texture: GRV-L, CNX-L, FLX-L
Rock fragments: mostly limestone with some sandstone; 35 to 75 percent total rock fragments; 20 to 40 percent gravel; 10 to 50 percent channers; 5 to 50 percent flagstones.
Calcium carbonate equivalent: 15 to 40 percent
EC (mmhos/cm): 0 to 2
Reaction: moderately alkaline or strongly alkaline
COMPETING SERIES: These are the Cedarknoll, Hackling, and Rencot series.
Cedarknoll soils formed in parent material derived from siltstone and sandstone and have siltstone and sandstone rock fragments.
Hackling soils have hue redder than 7.5YR.
Rencot soils have calcic horizons 5 inches or less from the surface.
GEOGRAPHIC SETTING: Schoonover soils.
Parent material: residuum derived from limestone.
Landform: plateaus and mountains.
Slopes: 3 to 25 percent
Elevation: 7,000 to 8,500 feet
Mean annual air temperature: 42 to 45 degrees F.
Mean annual precipitation: 12 to 16 inches.
Wettest months: Precipitation is relatively evenly distributed throughout the year.
Frost-free period: 75 to 95 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Berlake,
Emlin,
Layoint, and
Moosed series.
Berlake and Emlin soils have agrillic horizons.
Layoint and Moosed soils have sandy particle size control sections.
DRAINAGE AND PERMEABILITY: Well drained, low to high runoff, moderate permeability.
USE AND VEGETATION: The major uses are livestock grazing and wildlife habitat. The native plant community is bluebunch wheatgrass, black sagebrush, stemless goldenweed, and Indian ricegrass.
DISTRIBUTION AND EXTENT: Northwestern Colorado. LRR E, D, MLRA 47 and 34. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Moffat County, (Dinosaur National Monument) Colorado, 1997. The name is taken from a geographic location in the Dinosaur National Monument.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: The zone from 0 to 3 inches. (A horizon)
Calcic horizon: The zone from 3 to 11 inches. (Bk horizons)
Lithic contact: Hard limestone bedrock at ll inches. (R layer)
ADDITIONAL DATA: Percent calcium carbonate determined by calcimeter. Activity class is estimated.
Classification changed from Aridic Lithic Ustochrepts to Lithic Calciustepts 11/98.
Keys to Soil Taxonomy: Eight Edition, 1998