LOCATION COSOSA COEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Typic Haplocalcids
TYPICAL PEDON: Cososa loamy sand, 0 to 3 percent slopes in rangeland at an elevation of 7,500 feet. (Colors are for dry soil unless otherwise noted.) When described on June 19, 2000 the soil was dry throughout. The surface is covered by about 10 percent subrounded indurated gravel derived from granite, gneiss, and mica schist.
A--0 to 6 inches; pale brown (10YR 6/3) loamy sand, brown (10YR 5/3) moist; 5 percent clay; weak fine granular structure; very friable, soft, slightly sticky, slightly plastic; many fine roots throughout and many very fine roots throughout; many fine low continuity interstitial and many very fine low continuity interstitial pores; 2 percent fine gravel and 3 percent medium gravel; slightly alkaline (pH 7.6); clear smooth boundary. (3 to 8 inches)
Bw--6 to 14 inches; yellowish brown (10YR 5/4) gravelly fine sandy loam, dark yellowish brown (10YR 4/4) moist; 14 percent clay; weak medium subangular blocky structure, and weak fine subangular blocky structure; friable, slightly hard, slightly sticky, slightly plastic; common fine roots throughout and common very fine roots throughout; common fine low continuity dendritic tubular and common very fine low continuity dendritic tubular pores; 3 percent fine gravel and 12 percent medium gravel and 2 percent coarse gravel; slightly alkaline (pH 7.6); clear wavy boundary. (6 to 12 inches)
Bk1--14 to 21 inches; light yellowish brown (10YR 6/4) gravelly loamy sand, yellowish brown (10YR 5/4) moist; 10 percent clay; weak fine subangular blocky structure, and weak medium subangular blocky structure; friable, slightly hard, slightly sticky, slightly plastic; common fine roots throughout and common very fine roots throughout; common fine low continuity dendritic tubular and common very fine low continuity dendritic tubular pores; few fine irregular carbonate masses in matrix; slightly effervescent; 1 percent calcium carbonate equivalent; 5 percent fine gravel and 10 percent medium gravel and 1 percent coarse gravel; slightly alkaline (pH 7.8); gradual irregular boundary. (Combined thickness of Bk horizons: 20 to 50 inches)
Bk2--21 to 49 inches; pink (7.5YR 7/4) gravelly sandy clay loam, light brown (7.5YR 6/4) moist; 21 percent clay; weak fine subangular blocky structure; friable, slightly hard, slightly sticky, slightly plastic; few very fine roots throughout; common fine low continuity dendritic tubular and common fine low continuity vesicular and common very fine low continuity dendritic tubular and common very fine low continuity vesicular pores; common threadlike carbonate masses in matrix and many very coarse irregular carbonate masses around rock fragments; violently effervescent; 11 percent calcium carbonate equivalent; 5 percent fine gravel and 9 percent medium gravel and 1 percent coarse gravel; moderately alkaline (pH 8.0); clear wavy boundary. (0 to 35 inches)
2Bk1--49 to 57 inches; pale brown (10YR 6/3) gravelly loamy sand, brown (10YR 5/3) moist; 8 percent clay; single grain; loose, loose, nonsticky, nonplastic; few very fine roots throughout; common fine low continuity irregular pores; common threadlike carbonate masses in matrix and many very coarse irregular carbonate masses on bottom of rock fragments; strongly effervescent; 2 percent calcium carbonate equivalent; 8 percent fine gravel and 16 percent medium gravel; moderately alkaline (pH 8.0); clear wavy boundary.
2Bk2--57 to 74 inches; light yellowish brown (10YR 6/4) very gravelly coarse sand, yellowish brown (10YR 5/4) moist; 4 percent clay; single grain; loose, loose, nonsticky, nonplastic; few very fine roots throughout; common fine low continuity irregular pores; common threadlike carbonate masses in matrix and many very coarse irregular carbonate masses on bottom of rock fragments; strongly effervescent; 2 percent calcium carbonate equivalent; 11 percent fine gravel and 40 percent medium gravel and 2 percent coarse gravel; moderately alkaline (pH 8.0); clear wavy boundary.
2Bk3--74 to 80 inches; white (10YR 8/1) sandy loam, light gray (10YR 7/2) moist; 12 percent clay; massive; firm, hard, slightly sticky, slightly plastic; common fine low continuity vesicular and common very fine low continuity vesicular pores; many threadlike carbonate masses in matrix and many very coarse irregular carbonate masses on bottom of rock fragments; violently effervescent; 20 percent calcium carbonate equivalent; 5 percent fine gravel and 8 percent medium gravel; moderately alkaline (pH 8.2).
TYPE LOCATION: Costilla County, Colorado. La Sauses USGS quad; lat. 37 degrees 21 minutes 36.84 seconds N. and long. 105 degrees 42 minutes 22.97 seconds W.,
NAD 83
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 41 to 46 degrees F (5 to 8 degrees C)
Mean summer soil temperature: 59 to 63 degrees F (15 to 17 degrees C)
Depth to skeletal material: 40 to 60 inches (102 to 152 centimeters)
Depth to secondary calcium carbonate: 10 to 25 inches (25 to 64 centimeters)
Depth to calcic horizon: 6 to 25 inches (15 to 64 centimeters)
Depth to cambic horizon: 4 to 10 inches when present (10 to 25 centimeters)
Depth to lithologic discontinuity: 40 to 60 inches (102 to 152 centimeters)
Particle-size control section (weighted average):
Clay content: 8 to 17 percent
Rock fragments: 15 to 35 percent subrounded gravel
A horizon(s):
Hue: 7.5YR or 10YR
Value: 5 to 7, 4 to 6 moist
Chroma: 3 to 5
Texture: loamy sand
Clay content: 0 to 10 percent
Fragments: 0 to 15 percent subrounded indurated gravel derived from granite, gneiss, and mica schist
Calcium carbonate equivalent: 0 to 3 percent
Reaction: 7.4 to 8.4
Organic matter: 0 to 1 percent
Cation exchange capacity: 0 to 12 meq/100grams
Bw horizon(s):
Hue: 7.5YR or 10YR
Value: 4 to 6, 3 to 5 moist
Chroma: 3 to 5
Texture: gravelly fine sandy loam
Clay content: 10 to 20 percent
Fragments: 15 to 35 percent subrounded indurated gravel derived from granite, gneiss, and mica schist
Calcium carbonate equivalent: 0 to 3 percent
Reaction: 7.4 to 7.8
Cation exchange capacity: 1 to 16 meq/100grams
Bk horizon(s):
Hue: 7.5YR or 10YR
Value: 6 to 8, 5 to 7 moist
Chroma: 3 to 5
Texture: gravelly loamy sandy, gravelly sandy clay loam
Clay content: 5 to 35 percent
Fragments: 15 to 35 percent subrounded indurated gravel derived from granite, gneiss, and mica schist
Calcium carbonate equivalent: 0 to 20 percent
Reaction: 7.4 to 8.4
Cation exchange capacity: 0 to 14 meq/100grams
2Bk horizon(s):
Hue: 7.5YR or 10YR
Value: 5 to 8, 5 to 7 moist
Chroma: 1 to 4
Texture: gravelly loamy sand, very gravelly coarse sand, sandy loam
Clay content: 0 to 20 percent
Fragments: 0 to 60 percent subrounded indurated gravel derived from granite, gneiss, and mica schist
Calcium carbonate equivalent: 0 to 25 percent
Electrical conductivity: 2 to 5 mmhos/cm
Sodium adsorption ratio: 0 to 9
Reaction: 7.9 to 8.4
Cation exchange capacity: 0 to 17 meq/100grams
COMPETING SERIES: These are the
McGinty, Papal (T),
Sprabat, and
Teagulf series.
McGinty soils average less than 15 percent gravel in the control section.
Pepal soils: do not have a lithologic discontinuity at 40 to 60 inches
Sprabat soils: have tuff rock fragments.
Teagulf soils: are moderately deep.
GEOGRAPHIC SETTING:
Parent material: Outwash derived from granite, gneiss, and mica schist
Landform: outwash plains, outwash fans, and outwash terraces on intermontane basins
Slopes: 0 to 9 percent
Elevation: 7500 to 8000 feet
Mean annual temperature: 41 to 46 degrees F (5 to 8 degrees C)
Mean annual precipitation: 6 to 8 inches (15 to 20 centimeters)
Precipitation pattern: Precipitation peaks in July and August occurring mostly as intense summer thunderstorms
Frost-free period: 85 to 100 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Costilla: These soils have sandy control sections
Mosca: These soils have natric horizons
McGinty: These soils have less than 15 percent gravel in the control section
DRAINAGE AND PERMEABILITY: well drained, low runoff, moderately
rapid permeability
USE AND VEGETATION: These soils are principally rangeland; however, in some areas they are used for sprinkler irrigation for irrigated crops such as, potatoes and small grain. Typical vegetation is mainly rabbitbrush, blue grama, prickly pear, and sand dropseed.
DISTRIBUTION AND EXTENT: South-central Colorado, High Intermountain Valley, MLRA 51, LRR E. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Costilla County, 2009, Costilla County area soil survey,
Colorado. The name is coined.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 10 to 40 inches. (Bw, Bk horizons)
Ochric epipedon: The zone from 0 to 6 inches. (A horizon)
Cambic horizon: The zone from 6 to 14 inches. (Bw, Bk, and 2Bk horizons)
Calcic horizon: The zone from 21 to 49 inches. (Bk2 horizon)
Lithologic discontinuity: 49 inches
The series is supported by lab sample number S00CO023005.
Taxonomic Version: Tenth Edition, 2006