LOCATION ANTELOPEFLAT COTentative Series
TAXONOMIC CLASS: Fine, smectitic, mesic Aridic Haplusterts
TYPICAL PEDON: Antelopeflat clay, 0-1 percent slope in a dryland wheat stubble field at an elevation of 1447 meters (4748 feet) (Colors are for dry soil unless otherwise noted.)
Ap--0 to 13 centimeters (0 to 5 inches); dark grayish brown (10YR 4/2) broken face, clay, dark brown (10YR 3/3) crushed, moist; 45 percent clay; moderate coarse subangular blocky structure parting to moderate fine and medium subangular blocky structure; very hard, firm, very sticky, very plastic; common very fine roots throughout; common very fine and fine tubular pores and few medium tubular pores; neutral (pH 7.0); clear smooth boundary. (13 to 20 centimeters (5 to 8 inches thick)
Bw--13 to 31 centimeters (5 to 12 inches); brown (10YR 4/3) broken face, clay, dark brown (10YR 3/3) crushed, moist; 50 percent clay; moderate medium prismatic structure parting to strong fine and medium subangular blocky structure; very hard, very firm, very sticky, very plastic; common very fine roots throughout; many very fine tubular pores and common fine tubular pores; many distinct pressure faces on faces of peds; slightly alkaline (pH 7.6); clear smooth boundary. (0 to 36 centimeters (0 to 14 inches thick)
Bss--31 to 74 centimeters (12 to 29 inches); dark grayish brown (10YR 4/2) broken face, clay, dark grayish brown (10YR 4/2) crushed, moist; 52 percent clay; moderate fine and medium wedge structure parting to moderate medium prismatic structure parting to strong fine and medium subangular blocky structure; extremely hard, extremely firm, very sticky, very plastic; common very fine roots throughout; many very fine and fine tubular pores; few prominent slickensides (pedogenic) on tops of peds and many distinct pressure faces on faces of peds; moderately alkaline (pH 8.0); clear wavy boundary. (23 to 61 centimeters (9 to 24 inches thick)
Bssky--74 to 104 centimeters (29 to 41 inches); brown (10YR 5/3) broken face, clay, dark brown (10YR 3/3) crushed, moist; 47 percent clay; moderate medium and coarse wedge structure parting to moderate medium prismatic structure parting to strong fine, medium, and coarse subangular blocky structure; extremely hard, extremely firm, very sticky, very plastic; common very fine roots throughout; many very fine and common fine tubular pores; common prominent slickensides (pedogenic) on tops of peds; calcium carbonate occurs as common fine and medium irregular masses on faces of peds, very slight effervescent; few fine and medium irregular gypsum masses on faces of peds (EC = 1.18 mmhos/cm); moderately alkaline (pH 8.2); clear wavy boundary. (20 to 53 centimeters (8 to 21 inches thick)
2C--104 to 196 centimeters (41 to 77 inches); pale brown (10YR 6/3) broken face, coarse sandy loam, olive brown (2.5Y 4/3) crushed, moist; 8 percent clay; massive; soft, very friable, nonsticky, nonplastic; common very fine vesicular pores; secondary calcium carbonate is finely disseminated; slight effervescent; slightly alkaline (pH 7.8). (0 to 71 centimeters (0 to 28 inches thick)
TYPE LOCATION: Morgan County, Colorado; about 9 miles south of Wiggins; located about 213 meters (698 feet) west and 289 meters (948 feet) north of the SE corner of sec. 27, T. 2 N., R. 60 W.; Hoyt, Colorado USGS quad; UTM 578,612 meters E and 4439,831 meters N, Zone 13, NAD 83
RANGE IN CHARACTERISTICS:
Soil moisture: Ustic moisture regime bordering on Aridic.
Depth to secondary calcium carbonate: 13 centimeters (5 inches)
Depth to gypsum accumulations: 13 centimeters (5 inches)
Vertic features: depth to slickensides (pedogenic) 13 to 51 centimeters (5 to 20 inches)
Particle-size control section (weighted average):
Clay content: 45 to 65 percent
Sand content: 10 to 30 percent
Silt content: 25 to 45 percent
A horizon:
Hue: 2.5Y or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 through 4 dry, 2 through 4 moist
Texture: clay, clay loam, sandy clay
Clay content: 35 to 55 percent
Reaction: neutral to slightly alkaline
Bw horizon: (when present)
Hue: 2.5Y or 10YR
Value: 4 through 7 dry, 3 through 5 moist
Chroma: 1 through 4 dry, 2 through 4 moist
Texture: clay, clay loam
Clay content: 35 to 55 percent
Calcium carbonate equivalent: 1 to 6 percent
EC (mmhos/cm): 0 to 1
SAR: 1 to 3
Gypsum: 0 to 2 percent
Reaction: neutral to slightly alkaline
Bss horizon: (Bssky when present)
Hue: 2.5Y through 10YR
Value: 3 through 6 dry, 3 through 4 moist
Chroma: 1 through 4 dry, 2 through 4 moist
Texture: clay
Clay content: 45 to 60 percent
Calcium carbonate equivalent: 1 to 6 percent
EC (mmhos/cm): 1 to 4
SAR: 1 to 3
Gypsum: 0 to 3 percent
Reaction: slightly alkaline to moderately alkaline
Bk or Bky horizon: (when present)
Hue: 2.5Y through 10YR
Value: 5 through 6 dry, 3 through 5 moist
Chroma: 3 through 4 dry, 3 through 4 moist
Texture: sandy loam, loam, sandy clay loam
Clay content: 8 to 27 percent
Sand content: 35 to 65 percent
Calcium carbonate equivalent: 1 to 6 percent
EC (mmhos/cm): 1 to 3
SAR: 2 to 4
Gypsum: 0 to 2 percent
Reaction: slightly alkaline to moderately alkaline
2C horizon:
Hue: 2.5Y to 10YR
Value: 4 through 6 dry, 3 through 5 moist
Chroma: 2 through 4 dry, 2 through 4 moist
Texture: sandy loam, fine sandy loam, loamy sand, sand, coarse sand
Clay content: 2 to 20 percent
Sand content: 60 to 90 percent
Rock fragments: 0 to 5 percent gravel
Calcium carbonate equivalent: 1 to 6 percent
EC (mmhos/cm): 0 to 2
SAR: 2 to 4
Reaction: slightly alkaline to moderately alkaline
COMPETING SERIES:
Albers soils formed from sedimentary and volcanic rock.
Arboles soils occur on pediments, have a finer textured C horizon, and have a higher PE index.
Dominguez Hillrose (T) and
Sideshow soils are calcareous to the surface.
Ritoazul (T) has paralithic contact at 51 to 102 centimeters (20 to 40 inches)
Springerville soils formed from volcanic materials and have bedrock at 102 centimeters (40 inches)
GEOGRAPHIC SETTING:
Parent material: fine textured alluvium
Landform: paleo-stream terraces
Slopes: 0 to 1 percent
Elevation: 1387 to 1463 meters (4550 to 4800 feet)
Mean annual temperature: 8 to 10 degrees C (46 to 50 degrees F)
Mean annual precipitation: 31 to 36 centimeters (12 to 14 inches)
Precipitation pattern: peak periods during spring and early summer months
Frost-free period: 140 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
Bresser soils are fine-loamy, have argillic horizons, and have coarse materials at 51 to 102 centimeters (20 to 40 inches)
Bijou soils are coarse-loamy with argillic horizons.
Nunn soils are mollic and have argillic horizons.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: well drained
Runoff: high
Saturated hydraulic conductivity: very low
USE AND VEGETATION: Antelopeflat soils are used mainly for dry land crops. Wheat, millet, and sorghum are the principal crops.
DISTRIBUTION AND EXTENT: Antelopeflat soils occur in northeastern Colorado. The series is moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES PROPOSED: Morgan County, Colorado, 2004. The name Antelopeflat is from Antelope Flat Draw on the Hoyt, Colorado USGS Quad.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 25 to 100 centimeters (10 to 40 inches) (Bw, Bss, Bssky horizons)
Vertic features: The presence of slickensides at 31 to 104 centimeters (12 to 41 inches) (Bss, Bssky horizons)
The parent material is a fine alluvium laid over loamy alluvial sediments. The fine alluvium can range from 30 to 80 inches in thickness.
Because of the varying thickness of the fine alluvium, the control section may be fine-loamy in some pedons.
This series is being established in an area where land leveling is prevalent.
Taxonomic Version: Soil Taxonomy Ninth Edition, 2003
ADDITIONAL DATA: Soil sampled for characterization in 2003. NSSL Sample number is S03CO087006 and S03CO087005.