LOCATION TRAGMON COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Argiustolls
TYPICAL PEDON: Tragmon sandy loam on rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 2 inches; brown (10YR 5/3) sandy loam; dark brown (10YR 3/3) moist; single grain, loose, loose, nonsticky and nonplastic; many very fine roots throughout; 3 percent gravel; neutral (pH 7.2); abrupt smooth boundary.
A2--2 to 5 inches; brown (10YR 5/3) sandy loam; dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine roots throughout; few very fine vertical discontinuous tubular pores; 3 percent gravel; neutral (pH 7.2); clear smooth boundary.
A3--5 to 11 inches; brown (10YR 5/3) loam; dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine roots throughout; few very fine vertical discontinuous tubular pores; 3 percent gravel and 1 percent cobbles; neutral (pH 7.2); clear smooth boundary. (combined thickness of A horizons 10 to 16 inches)
Bt1--11 to 36 inches; pale brown (10YR 6/3) loam; dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine roots throughout; few very fine oblique and few fine oblique discontinuous tubular pores; common faint clay films on faces of peds and in pores; 3 percent gravel; neutral (pH 7.2); clear smooth boundary.
Bt2--36 to 40 inches; yellowish brown (10YR 5/4) loam; brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; 3 percent gravel; neutral (pH 7.2); gradual smooth boundary. (combined thickness of Bt horizons 15 to 40 inches)
C1--40 to 48 inches; light yellowish brown (10YR 6/4) loam; dark yellowish brown (10YR 4/4) moist; massive; hard firm, slightly sticky and slightly plastic; 7 percent gravel; neutral (pH 7.2); clear smooth boundary.
C2--48 to 60 inches; light yellowish brown (10YR 6/4) loam; dark yellowish brown (10YR 4/4) moist; massive; hard firm, slightly sticky and slightly plastic; 7 percent gravel; slightly effervescent; slightly alkaline (pH 7.8). (combined thickness of C horizons 10 to 35 inches)
TYPE LOCATION: Montezuma County, at the base of the Navajo Canyon trail, east fork of Navajo Canyon, Mesa Verde National Park, about 2,900 feet east and 2,500 feet north of the southwest corner of sec. 33, T. 35 N., R. 15 W. Wetherill Mesa, Colorado USGS Quad. Lat. 37 degrees 14 minutes 45 seconds, Long. 108 degrees 30 minutes, 27 seconds, NAD 27
RANGE IN CHARACTERISTICS:
Soil moisture regime: ustic
Soil temperature regime: frigid
Mean annual soil temperature: 45 to 48 degrees F
Mean annual summer soil temperature: 59 to 60 degrees F
Particle-size control section: 18 to 35 percent clay
Thickness of the mollic epipedon: 7 to 16 inches
A horizon:
Hue: 10YR
Value: 3 to 5 (2 or 3 moist)
Chroma: 2 or 3
Rock fragments: 0 to 20 percent
Reaction: slightly acid to slightly alkaline
Bt horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6 (3 to 5 moist)
Chroma: 2 to 6
Texture: loam, sandy clay loam, or clay loam
Rock fragments: 0 to 20 percent
Reaction: neutral to moderately alkaline
C horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6 (3 to 5 moist)
Chroma: 2 to 6
Texture: clay loam, sandy clay loam, or loam
Rock fragments: 0 to 30 percent
Reaction: neutral to moderately alkaline
COMPETING SERIES: These are the Absarook, Archmesa, Bielenberg, Burtoner, Clancy, Clasoil, Dooley, Doughty, Empedrado, Fairfield, Farnuf, Farside, Felor, Greenway, Gurney, Hangdo, Hoppers, Hyalite, Jeffcity, Kokoruda, Livona, Martinsdale, Maudlin, Meagher, Moen, Moento, Pianohill, Placerton, Reeder, Reedwest, Snakejohn, Trazuni, Ulrant, Vida, Watne, Watrous, Williams, and Yegen series. Potential competitors still classified as Borolls are the Beartooth, Beeno, Bookcliff, and Sponseller soils. Beartooth, Beeno, Dooley, Doughty, Empedrado, Fairfield, Farnuf, Gurney, Kokoruda, Martinsdale, Meagher, Ulrant, Watne, Williams, and Yegen soils have secondary carbonate accumulations above 40 inches. Farside soils have mean annual soil temperature of 39 to 43 degrees F. The Felor, Greenway, and Livona soils have lithologic discontinuities and lime carbonates above 40 inches. Hyalite soils contain more than 40 percent rock fragments in the 2Bt horizon and below. Clasoil soils are derived from granitic rocks. The Absarook, Archmesa, Burtoner, Clancy, Hoppers, Jeffcity, Moento, Pianohill, Placerton, Reeder, and Reedwest soils have a paralithic or lithic contact between 20 to 40 inches. Trazuni soils have mottles in the lower part of the profile. The Bielenberg and Snakejohn soils have lithic contact between 40 and 60 inches. The Maudlin, Moen, and Watrous soils have a lithic contact at depths of 20 to 40 inches. The Bookcliff and Vida soils have lime carbonates, chroma depth of 40 inches, and sola to the base of the Bt is less than 20 inches. The Hangdo series has more than 15 percent coarse fragments in the lower subsoil or substratum. Sponseller series have hues redder than 7.5YR in the lower solum.
GEOGRAPHIC SETTING:
Parent material: colluvium, slope alluvium and alluvium derived from shale and sandstone
Landform: hills, canyons, mesas, and alluvial fans
Slopes: 1 to 20 percent
Elevation: 7,100 to 8,500 feet
Mean annual temperature: 43 to 47 degrees F
Mean annual precipitation: 15 to 20 inches
Frost-free period: 75 to 100 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Sheek and Beje soils. Beje soils have bedrock at depths of less than 20 inches. Sheek soils are loamy skeletal and lack a mollic epipedon.
DRAINAGE AND PERMEABILITY: well drained, low to high runoff, moderate permeability
USE AND VEGETATION: The soils are used for rangeland. Native vegetation is mainly Gamble oak, serviceberry, mountain mahogany, and muttongrass.
DISTRIBUTION AND EXTENT: Southwest Colorado. LRR D, MLRA 39. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Cortez Soil Survey Area, Montezuma County, Colorado. 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
mollic epipedon: The zone from 0 to 11 inches. (A)
argillic horizon: The zone from 11 to 40 inches. (Bt1, Bt2)
particle-size control section: The zone from 11 to 31 inches. (Bt1, Bt2)
Soil Taxonomy Second Edition, 1999