LOCATION RAVINE COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Ustic Calciargids
TYPICAL PEDON: Ravine silty clay loam, on a northeast facing, convex, 2 percent slope in grass at an elevation of 5235 feet. (Colors are for dry soil unless otherwise noted.) When described on July 17, 2001 the soil was dry throughout.
A--0 to 3 inches; brown (10YR 5/3) silty clay loam, brown (10YR 4/3) moist; moderate fine granular structure; very friable, soft, slightly sticky and slightly plastic; many fine and medium roots throughout; strong effervescence (11 percent calcium carbonate equivalent); slightly alkaline (pH 7.8); abrupt smooth boundary. (3 to 5 inches thick)
Btk1--3 to 14 inches; yellowish brown (10YR 5/4) silty clay, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; very firm, very hard, moderately sticky and moderately plastic; many fine and medium roots throughout; 30 percent continuous distinct clay films on faces of peds; 3 percent medium distinct irregular carbonate masses; violent effervescence (11 percent calcium carbonate equivalent); moderately alkaline (pH 8.2); clear wavy boundary.
Btk2--14 to 21 inches; light yellowish brown (2.5Y 6/3) silty clay, olive brown (2.5Y 4/4) moist; moderate medium prismatic parting to strong fine and medium subangular blocky structure; very firm, extremely hard, very sticky and very plastic; common fine and medium roots throughout; 40 percent continuous distinct clay films on faces of peds; 8 percent medium distinct irregular carbonate masses; 2 percent angular gravel; violent effervescence (19 percent calcium carbonate equivalent); moderately alkaline (pH 8.2); clear smooth boundary. (Combined thickness of the Bt1 and Bt2 horizons is 12 to 25 inches)
Btk3--21 to 28 inches; grayish brown (2.5Y 5/2) silty clay, dark grayish brown (2.5Y 4/2) moist; strong coarse prismatic parting to strong fine and medium subangular blocky structure; very firm, extremely hard, very sticky and very plastic; few very fine roots throughout; 45 percent continuous distinct clay films on faces of peds; 10 percent medium and coarse distinct irregular carbonate masses; 2 percent angular gravel and 10 percent flat weakly cemented 2 to 75 millimeter shale fragments; violent effervescence (12 percent calcium carbonate equivalent); moderately alkaline (pH 8.2); abrupt smooth boundary. (5 to 10 inches thick)
Cr--28 to 40 inches; thin platy fractured, gypsiferous shale.
TYPE LOCATION: Las Animas County, Colorado; about 1.5 miles west of Delhi; located about 2,250 feet east and 2,300 feet south of the northwest corner of sec. 6, T. 28 S., R. 59 W.; Delhi USGS quad; lat. 37 degrees 38 minutes 19 seconds N. and long. 104 degrees 3 minutes 6 seconds W., NAD 1927
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is moist intermittently April through August and are driest December through February; aridic moisture regime bordering on ustic.
Mean annual soil temperature: 49 to 54 degrees F
Mean summer soil temperature: 70 to 74 degrees F
Depth to argillic horizon: 3 to 5 inches
Depth to secondary calcium carbonate: 0 to 3 inches
Depth to calcic horizon: 10 to 21 inches
Thickness of the argillic horizon: 15 to 35 inches
Thickness of the calcic horizon: 12 to 25 inches
Particle-size control section (weighted average):
Clay content: 40 to 55 percent
Sand content: 10 to 20 percent, dominantly very fine and fine sand
Rock fragments: 0 to 15 percent gravel
A horizon:
Hue: 10YR or 2.5Y
Value: 4 to 6 dry, 3 or 4 moist
Chroma: 2 or 3
Clay content: 20 to 35 percent
Rock fragments: 0 to 5 percent gravel
Calcium carbonate equivalent: 0 to 5 percent
Reaction: slightly alkaline or moderately alkaline
Bt1 & Bt2 horizons:
Hue: 10YR or 2.5Y
Value: 5 to 7 dry, 4 or 5 moist
Chroma: 2 to 4
Texture: silty clay loam, silty clay, clay
Clay content: 35 to 60 percent
Rock fragments: 0 to 5 percent gravel
Calcium carbonate equivalent: 10 to 35 percent
EC (mmhos/cm): 0 to 2
Reaction: moderately alkaline or strongly alkaline
Bt3 horizon:
Hue: 10YR or 2.5Y
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 4
Texture: silty clay, clay
Clay content: 40 to 60 percent
Rock fragments: 0 to 15 percent gravel
Pararock fragments: 5 to 25 percent shale fragments
Calcium carbonate equivalent: 5 to 20 percent
EC (mmhos/cm): 1 to 6
Gypsum: 0 to 5 percent
SAR: 1 to 10
Reaction: moderately alkaline or strongly alkaline
Cr horizon:
Calcium carbonate equivalent: 1 to 10 percent
COMPETING SERIES: There are no competing series in the fine smectitic family. Similar series in the mixed family are the
Alesna(NM),
Hano(AZ),
Keeseha(AZ), and
Poley(AZ) series.
Alesna soils: have a paralithic contact at depths of 40 to 60 inches
Hano soils: are moist December through March
Keeseha and Poley soils: do not have a paralithic contact
GEOGRAPHIC SETTING:
Parent material: alluvium and residuum derived from shale
Landform: plains, fans, pediments
Slopes: 1 to 5 percent
Elevation: 5000 to 6000 feet
Mean annual temperature: 50 to 54 degrees F
Mean annual precipitation: 12 to 14 inches
Precipitation pattern: wettest period May through August, driest December through February
Frost-free period: 135 to 155 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Manzanola, Minnequa, and Wilid series. The Manzanola and Wilid soils are very deep and are on plains. The Minnequa soils average less than 35 percent clay in the control section and are on plains, ridges and hills.
DRAINAGE AND PERMEABILITY: Well drained, low to medium runoff, slow permeability.
USE AND VEGETATION: Rangeland and wildlife habitat. The native vegetation is mainly blue grama, galleta, western wheatgrass, bottlebrush squirreltail, and cacti.
DISTRIBUTION AND EXTENT: Southeastern Colorado; LRR G, MLRA 69; moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES PROPOSED: Las Animas County, Colorado, Las Animas County soil survey area, Colorado. The name is a type of gully.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Series control section: The zone from 3 to 23 inches.
Particle-size control section: The zone from 3 to 28 inches. (Bt1, Bt2 and Bt3 horizons)
Ochric epipedon: The zone from 0 to 3 inches. (A horizons)
Argillic horizon: The zone from 3 to 28 inches. (Bt1, Bt2 and Bt3 horizons)
Calcic horizon: The zone from 14 to 21 inches. (Bt2 horizon)
Lithic contact: The contact with ? at ? inches. (? horizons)
Paralithic contact: The contact with shale at 28 inches. (Cr horizon)
Other features: ustic aridic moisture regime.
Remarks: This soil was separated from the Razor series due to the presence of calcic and argillic horizons.
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomic Version: Second Edition, 1999
ADDITIONAL DATA: