LOCATION BOXCANYON COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Calcidic Haplustalfs
TYPICAL PEDON: Boxcanyon silt loam, on a north facing, nearly level, 1 percent slope at an elevation of 5,428 feet. (Colors are for dry soil unless otherwise noted.) When described on July 4, 2000 the soil was moist from 45 to 54 inches.
A--0 to 2 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; noneffervescent; slightly alkaline (pH 7.6); abrupt smooth boundary. (2 to 4 inches thick)
Bt--2 to 17 inches; brown (10YR 5/3) silty clay loam, brown (10YR 4/3) moist; strong medium prismatic structure parting to strong fine and medium subangular blocks; very hard, firm, sticky and plastic; many very fine roots; common continuous distinct clay films on faces of peds; slightly effervescent; 2 percent calcium carbonate equivalent; moderately alkaline (pH 8.0); clear smooth boundary. (12 to 20 inches thick)
Btk1--17 to 27 inches; brown (7.5YR 5/4) clay, brown (7.5YR 4/4) moist; strong fine and medium prismatic structure parting to strong fine and medium angular blocks; extremely hard, very firm, very sticky and very plastic; common very fine roots; common continuous clay films on faces of peds; violently effervescent; 10 percent calcium carbonate equivalent; common medium irregular soft masses of calcium carbonate; moderately alkaline (pH 8.2); clear wavy boundary.
Btk2--27 to 33 inches; light brown (7.5YR 6/4) silty clay loam, brown (7.5YR 5/4) moist; strong medium prismatic structure parting to moderate fine and medium subangular blocks; extremely hard, firm, sticky and plastic; few fine roots; few patchy distinct clay films on faces of peds; violently effervescent; 13 percent calcium carbonate equivalent; common fine and medium irregular soft masses of calcium carbonate; moderately alkaline (pH 8.4); abrupt wavy boundary. (Combined thickness of the Btk horizons is 12 to 18 inches thick)
Bk1--33 to 45 inches; very pale brown (10YR 8/4) loam, light yellowish brown (10YR 6/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; violently effervescent; 42 percent calcium carbonate equivalent; moderately alkaline (pH 8.2), clear smooth boundary. (8 to 12 inches thick)
2Bk2--45 to 54 inches; light yellowish brown (10YR 6/4) gravelly loam, yellowish brown (10YR 5/4) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; 18 percent sandstone gravel; violently effervescent; 17 percent calcium carbonate equivalent; common fine irregular soft masses of calcium carbonate, few fine irregular gypsum crystals; moderately alkaline (pH 8.2), abrupt wavy boundary.
2R--54 to 72 inches; hard Dakota sandstone.
TYPE LOCATION: Las Animas County, Colorado; located about 800 feet north and 20 feet east of the southwest corner of sec. 34, T. 31 S., R. 57 W.; Doss Canyon South USGS quad; lat. 37 degrees 17 minutes 48 seconds N. and long. 103 degrees 47 minutes 38 seconds W.; NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is moist intermittently April through August; Ustic moisture regime bordering on aridic.
Mean annual soil temperature: 50 to 53 degrees F
Mean summer soil temperature: 66 to 72 degrees F
Depth to lithic contact: 40 to 60 inches to sandstone
Depth to secondary calcium carbonate: 0 to 8 inches
Depth to calcic horizon: 29 to 40 inches
Thickness of the argillic horizon: 26 to 38 inches
Particle-size control section (weighted average):
Clay content: 35 to 46 percent
Sand content: 5 to 20 percent
A horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 or 3
Clay content: 18 to 27 percent
Reaction: neutral or slightly alkaline
Bt horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: silty clay loam, silty clay, clay
Clay content: 35 to 50 percent
Calcium carbonate equivalent: 1 to 5 percent
Reaction: slightly alkaline or moderately alkaline
Btk horizons:
Hue: 7.5YR or 10YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 3 to 6
Texture: silty clay loam, silty clay, clay
Clay content: 35 to 45 percent
Calcium carbonate equivalent: 5 to 15 percent
Reaction: moderately alkaline to strongly alkaline
Bk1 horizon:
Hue: 7.5YR or 10YR
Value: 6 to 8 dry, 5 to 7 moist
Chroma: 3 to 6
Texture: loam, clay loam, silty clay loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 5 percent
Calcium carbonate equivalent: 20 to 50 percent
Reaction: moderately alkaline or strongly alkaline
2Bk2 horizon:
Hue: 7.5YR or 10YR
Value: 6 to 8 dry, 5 to 7 moist
Chroma: 3 to 6
Texture of the fine earth fraction: loam, sandy clay loam, silt loam
Clay content: 15 to 27 percent
Rock fragments: 15 to 35 percent
Calcium carbonate equivalent: 15 to 50 percent
Gypsum: 0 to 2 percent
Reaction: moderately alkaline to strongly alkaline
COMPETING SERIES: There are presently no competing series. Similar soils in the fine-silty family are the Cahoma (CO),
Plughat (CO), and
Villegreen (CO) series.
Cahoma soils: are very deep soils and have hues of 5YR.
Plughat soils: average less than 35 percent clay in the control section.
Villegreen soils: have a lithic contact from 20 to 40 inches deep.
GEOGRAPHIC SETTING:
Parent material: Loess over residuum derived from sedimentary deposits.
Landform: Plains
Slopes: 0 to 3 percent
Elevation: 5,000 to 6,500 feet
Mean annual temperature: 50 to 53 degrees F
Mean annual precipitation: 14 to 16 inches
Precipitation pattern: Wettest period: April through August and the driest period is November through February
Frost-free period: 130 to 155 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Baca, Wiley, Plughat, and Villegreen series. The Baca and Wiley soils are very deep and are on plains. The Plughat soils average less than 35 percent clay and are on plains. Villegreen soils average less than 35 percent clay, have a lithic contact at depths of 20 to 40 inches and are on plains.
DRAINAGE AND PERMEABILITY: Well drained, low to medium runoff, slow permeability.
USE AND VEGETATION: Rangeland and wildlife habitat. The native vegetation is blue grama, western wheatgrass, red threeawn, bottlebrush squirreltail, cholla, prickly pear, and yucca.
DISTRIBUTION AND EXTENT: Southeastern Colorado; LRR G, MLRA 67; the series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES PROPOSED: Las Animas County, Colorado, Las Animas County and parts of Huerfano County soil survey area, Colorado. The name is coined from a canyon in the area.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 2 to 22 inches. (Bt and Btk1 horizons)
Ochric horizon: The zone from 0 to 2 inches. (A horizons)
Argillic horizon: The zone from 2 to 33 inches. (Bt, Btk1, and Btk2 horizons)
Calcic epipedon: The zone from 33 to 54 inches. (Bk1 and 2Bk2 horizons)
Lithic contact: The contact with sandstone at 54 inches. (2R horizon)
Remarks: This update represents moving the type location to a larger, more representative area.
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