LOCATION TRINCHERA COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Ustic Calciargids
TYPICAL PEDON: Trinchera fine sandy loam, 0 to 1 percent slopes in rangeland at an elevation of 7,641 feet. (Colors are for dry soil unless otherwise stated.) The surface is covered by about 5 percent subrounded indurated gravel derived from granite, gneiss, and mica schist
A--0 to 10 centimeters; brown (7.5YR 4/3) fine sandy loam, dark brown (7.5YR 3/3) moist; 10 percent clay; weak fine granular structure; very friable, soft, nonsticky, nonplastic; common very fine and common fine roots throughout; common very fine irregular pores; 5 percent gravel; noneffervescent; slightly alkaline (pH 7.4); clear smooth boundary. (5 to 20 centimeters thick)
Bt--10 to 38 centimeters; brown (7.5YR 5/3) loam, brown (7.5YR 4/4) moist; 21 percent clay; moderate fine subangular blocky structure, and moderate medium subangular blocky structure; friable, slightly hard, moderately sticky, moderately plastic; common very fine and common fine roots throughout; common very fine dendritic tubular pores; common discontinuous faint clay films and common discontinuous faint clay bridging; 5 percent gravel; noneffervescent; slightly alkaline (pH 7.4); clear wavy boundary. (18 to 38 centimeters thick)
Btk--38 to 71 centimeters; pink (7.5YR 7/3) loam, brown (7.5YR 5/3) moist; 18 percent clay; moderate medium subangular blocky structure, and moderate fine subangular blocky structure; friable, hard, moderately sticky, moderately plastic; common very fine roots throughout; common very fine dendritic tubular pores; common discontinuous faint clay bridging and common discontinuous faint clay films; common carbonate masses around rock fragments and many carbonate masses in matrix; 5 percent gravel; strongly effervescent (27 percent calcium carbonate equivalent); moderately alkaline (pH 8.0); gradual wavy boundary. (13 to 38 centimeters thick)
Bk1--71 to 102 centimeters; pink (7.5YR 8/3) loam, light brown (7.5YR 6/3) moist; 15 percent clay; moderate medium subangular blocky structure, and moderate fine subangular blocky structure; friable, hard, moderately sticky, moderately plastic; common very fine roots throughout; common very fine dendritic tubular pores; common carbonate masses around rock fragments and many carbonate masses in matrix; 5 percent gravel; violently effervescent (42 percent calcium carbonate equivalent); moderately alkaline (pH 8.2); clear wavy boundary. (13 to 38 centimeters thick)
Bk2--102 to 142 centimeters; pink (7.5YR 7/3) loam, brown (7.5YR 5/3) moist; 15 percent clay; moderate medium subangular blocky structure, and moderate fine subangular blocky structure; friable, hard, moderately sticky, moderately plastic; common very fine roots throughout; common very fine dendritic tubular pores; common carbonate masses around rock fragments and many carbonate masses in matrix; 5 percent gravel; strongly effervescent (16 percent calcium carbonate equivalent); moderately alkaline (pH 8.2); gradual wavy boundary. (25 to 51 centimeters thick)
Bk3--142 to 178 centimeters; light brown (7.5YR 6/3) loam, brown (7.5YR 4/3) moist; 13 percent clay; weak medium subangular blocky structure, and weak fine subangular blocky structure; friable, slightly hard, slightly sticky, slightly plastic; common very fine dendritic tubular pores; common carbonate masses around rock fragments and many carbonate masses in cracks; 5 percent gravel; strongly effervescent (14 percent calcium carbonate equivalent); moderately alkaline (pH 8.0); gradual wavy boundary. (25 to 51 inches thick)
Bk4--178 to 203 centimeters; light brown (7.5YR 6/4) sandy loam, brown (7.5YR 5/4) moist; 12 percent clay; massive; friable, slightly hard, slightly sticky, slightly plastic; common very fine irregular pores; common carbonate masses around rock fragments and many carbonate masses in matrix; 5 percent gravel; strongly effervescent (7 percent calcium carbonate equivalent); moderately alkaline (pH 8.0).
TYPE LOCATION: Costilla County, Colorado; Garcia topographic USGS quadrangle; 37 degrees 3 minutes 18.99 seconds North latitude and 105 degrees 32 minutes 26.82 seconds West longitude UTM 451,918 meters E, 4101,141 meters N, zone 13.
RANGE IN CHARACTERISTICS:
Soil moisture:
Soil moisture regime subclass: Ustic
Soil moisture regime class: aridic (torric)
Mean annual soil temperature: 41 to 46 degrees F (5.0 to 7.8 degrees C)
Mean summer soil temperature: 63 to 66 degrees F (17.2 to 18.9 degrees C)
Depth to argillic horizon: 3 to 7 inches (8 to 18 centimeters)
Depth to calcic horizon: 12 to 25 inches (30 to 64 centimeters)
Thickness of argillic horizon: 5 to 25 inches (13 to 64 centimeters)
Thickness of calcic horizon: 20 to 65 inches (51 to 165 centimeters)
Surface fragments: 0 to 15 percent subrounded indurated gravel derived from granite, gneiss, and mica schist
Particle-size control section (weighted average):
Clay content: 15 to 26 percent
Sand content: 35 to 60 percent
Rock fragment content: 0 to 15 percent
A horizon(s)
Hue: 7.5YR or 10YR
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 2 or 3
Texture: fine sandy loam
Clay content: 10 to 18 percent
Sand content: 52 to 82 percent
Silt content: 20 to 40 percent
Fragment content, total: 0 to 15 percent
Fragment size and content: 0 to 15 percent indurated gravel derived from granite, gneiss, and mica schist
Calcium carbonate equivalent: 0 to 2 percent
Reaction: pH 6.6 to 7.8
Bt horizon(s)
Hue: 7.5YR or 10YR
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 3 or 4
Texture: sandy clay loam, loam
Clay content: 18 to 26 percent
Sand content: 35 to 60 percent
Silt content: 20 to 40 percent
Fragment content, total: 0 to 15 percent
Fragment size and content: 0 to 15 percent indurated gravel derived from granite, gneiss, and mica schist
Calcium carbonate equivalent: 0 to 5 percent
Reaction: pH 6.6 to 7.8
Btk horizon(s)
Hue: 7.5YR or 10YR
Value: 6 to 8 dry; 5 to 7 moist
Chroma: 3 or 4
Texture: loam, sandy clay loam
Clay content: 15 to 26 percent
Sand content: 35 to 55 percent
Silt content: 20 to 40 percent
Fragment content, total: 0 to 15 percent
Fragment size and content: 0 to 15 percent indurated gravel derived from granite, gneiss, and mica schist
Calcium carbonate equivalent: 15 to 35 percent
Reaction: pH 7.4 to 8.4
Bk horizon(s)
Hue: 7.5YR or 10YR
Value: 6 to 8 dry; 4 to 6 moist
Chroma: 3 or 4
Texture: loam, sandy loam
Clay content: 8 to 18 percent
Sand content: 40 to 70 percent
Silt content: 20 to 46 percent
Fragment content, total: 0 to 15 percent
Fragment size and content: 0 to 15 percent indurated gravel derived from granite, gneiss, and mica schist
Calcium carbonate equivalent: 3 to 45 percent
Reaction: pH 7.4 to 8.4
COMPETING SERIES: These are the
Alogia,
Anchutz,
Antonito,
Cushool,
Cutback,
Fluetsch,
Fonce,
Grubrob,
Hickey,
Potrio,
Rock River,
Stunner and
Wycolo soils.
Alogia soils have secondary accumulations of gypsum in the solum
Anchutz soils have strongly alkaline to very strongly alkaline reaction.
Antonito soils have a lithic contact above 40 inches.
Cushool soils have a paralithic contact at depths of 20 to 40 inches.
Cutback soils have a paralithic contact at depths of 20 to 40 inches.
Fluetsch have argillic horizons at depths greater than 12 inches.
Fonce soils have subhorizons containing 35 to 60 percent rock fragments.
Hickey soils have hues of 5YR and redder in the Bt, Bk and/or 2C horizons and have a clay percentage that ranges from 20 to 35 in the particle control section.
Rock River soils have a clay percentage that ranges from 20 to 35 in the particle control section.
Stunner soils have a rock fragment content that ranges from 15 to 30 percent in the solum and Bk horizons above a depth of 40 inches, and the size ranges from coarse gravel to cobbles.
Wycolo soils have a paralithic contact at depths of 20 to 40 inches.
GEOGRAPHIC SETTING:
Parent material: outwash derived from granite, gneiss, and mica schist
Landform: outwash plains, outwash fans
Slopes: 0 to 9 percent
Elevation: 7,500 to 8,500 feet (2,286 to 2,591 meters)
Mean annual precipitation: 8 to 12 inches (203 to 305 millimeters)
Precipitation pattern: Precipitation peaks in July and August occurring mostly as intense summer thunderstorms.
Frost-free period: about 85 to 100 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are
Kibin and
Stunner soils.
Kibin soils are on terraces and fan remnants and have a mollic epipedon.
Stunner soils have less than 35 percent sand in the series control section.
DRAINAGE AND PERMEABILITY: Well drained, medium to rapid runoff, moderate permeability
USE AND VEGETATION: The major use is rangeland and wildlife habitat. Some areas are irrigated cropland produce small grains, alfalfa and domestic grasses. Native vegetation is Wyoming big sagebrush, rabbitbrush, blue grama, western wheatgrass, needleandthread, Indian ricegrass, bottlebrush squirreltail, and prairie Junegrass.
DISTRIBUTION AND EXTENT: San Luis Valley Area of south central Colorado. LRR E, MLRA 51. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Costilla County Area, Colorado; 2009
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--0 to 4 inches (10 centimeters) A horizon
Argillic horizon--4 to 28 inches (10 to 71 centimeters) Bt, Btk horizons.
Calcic horizon--15 to 56 inches (38 to 142 centimeters) Btk, Bk horizons.
Taxonomic version: Tenth edition, 2006