LOCATION GRANEROS COEstablished Series
TAXONOMIC CLASS: Fine, smectitic Ustic Glossocryalfs
TYPICAL PEDON: Graneros gravelly loam, on a south facing, convex, 15 percent slope in mixed conifers at an elevation of 9,880 feet. (Colors are for dry soil unless otherwise noted.) When described on June 19, 1986 the soil was moist from 0 to 27 inches. The surface is covered by 5 percent stones.
Oi--0 to 1 inches; slightly decomposed plant material.
A--1 to 3 inches; dark gray (10YR 4/1) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, friable, slightly sticky and slightly plastic; common fine and medium roots; 20 percent gravel, 5 percent cobbles, 5 percent stones; neutral (pH 6.8); abrupt smooth boundary. (0 to 3 inches thick)
E--3 to 7 inches; light gray (10YR 7/2) gravelly loam, dark grayish brown (10YR 4/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; common fine and medium roots; 20 percent gravel, 5 percent cobbles; moderately acid (pH 5.6); abrupt smooth boundary. (3 to 5 inches thick)
Bt/E--7 to 13 inches; 60 percent light yellowish brown (10YR 6/4) gravelly clay loam, dark yellowish brown (10YR 4/4) moist; 40 percent light gray (10YR 7/2) gravelly loam, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; hard, firm, sticky and slightly plastic; few fine and medium roots; common thin patchy clay films on faces of peds (Bt); 25 percent gravel; slightly acid pH 6.4); clear smooth boundary. (2 to 7 inches thick)
Bt1--13 to 23 inches; light yellowish brown (10YR 6/4) gravelly clay, dark yellowish brown (10YR 4/4) moist; weak medium prismatic structure parting to strong medium blocky; very hard, very firm, very sticky and slightly plastic; few fine and medium roots; many continuous distinct clay films on faces of peds; 20 percent gravel; slightly acid pH 6.4); clear smooth boundary.
Bt2--23 to 32 inches; light yellowish brown (10YR 6/4) and very pale brown (10YR 7/4) parachannery silty clay loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; hard, firm, sticky and plastic; few fine and medium roots; common patchy distinct clay films on faces of peds; 20 percent siltstone parafragments; slightly acid pH 6.3); gradual wavy boundary. (Combined thickness of the Bt1 and Bt2 horizons is 15 to 25 inches thick)
Cr--32 to 43 inches; soft shale and siltstone.
TYPE LOCATION: Las Animas County, Colorado; about 1.4 miles southeast of Cucharas Pass; located about 2,100 feet north 650 and west feet of the southeast corner of sec. 25, T. 31 S., R. 69 W.; Cucharas Pass USGS quad; lat. 37 degrees 18 minutes 56 seconds N. and long. 105 degrees 2 minutes 54 seconds W., NAD 1927
RANGE IN CHARACTERISTICS: (Depths are from the mineral soil surface)
Soil moisture: The soil moisture control section is moist from March through September, driest December through February; Udic moisture regime bordering on ustic.
Mean annual soil temperature: 38 to 42 degrees F
Mean summer soil temperature: 44 to 47 degrees F
Depth to paralithic contact: 20 to 40 inches to shale and siltstone
Depth to glossic horizon: 3 to 8 inches
Thickness of the argillic horizon: 15 to 25 inches
Particle-size control section (weighted average):
Clay content: 35 to 45 percent
Sand content: 5 to 35 percent
Rock fragments: 15 to 35 percent, dominantly gravel and cobbles
A horizon:
Hue: 7.5YR to 2.5Y
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 to 3
Clay content: 18 to 27 percent
Rock fragments: 15 to 35 percent
Reaction: slightly acid or neutral
E horizon:
Hue: 7.5YR to 2.5Y
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 2 or 3
Clay content: 20 to 27 percent
Rock fragments: 15 to 35 percent
Reaction: moderately acid to neutral
Bt/E horizon:
Same properties as overlying E and underlying Bt horizons.
Bt horizons:
Hue: 7.5YR to 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 to 6
Texture of the fine earth fraction: clay loam, silty clay loam, silty clay, clay
Clay content: 35 to 45 percent
Rock fragments: 15 to 35 percent in the Bt1, 0 to 15 percent in the Bt2
Pararock fragments: 15 to 35 percent shale and siltstone fragments in the Bt2
Base saturation: 60 to 100 percent
Reaction: slightly acid or neutral
COMPETING SERIES: These are the
Cowd (CO),
Dell (WY) and
Tercio(CO) series.
Cowd soils: are greater than 60 inches to paralithic contact.
Dell soils: are 40 to 60 inches deep to fractured limestone.
Tercio soils: are greater than 60 inches to paralithic contact.
GEOGRAPHIC SETTING:
Parent material: slope alluvium and colluvium derived from shale and siltstone, commonly from the Raton Formation.
Landform: mountain slopes
Slopes: 15 to 40 percent
Elevation: 8,000 to 10,000 feet
Mean annual temperature: 38 to 42 degrees F
Mean annual precipitation: 20 to 26 inches
Precipitation pattern: continental
Wettest period: April through August
Driest period: December through February
Frost-free period: 40 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bandarito, Dargol, Fuera, and Tercio series. The Bandarito soils have a mollic epipedon and are on valley sides. The Dargol and Fuera soils have a frigid temperature regime and are on south facing mountain slopes. The Tercio soils are very deep and are on mountain slopes.
DRAINAGE AND PERMEABILITY: Well drained, rapid runoff, slow permeability.
USE AND VEGETATION: Woodland and wildlife habitat. The native vegetation is Rocky Mountain Douglas fir, white fir, Engelmann's spruce with an understory of common juniper, kinninnick, Gambel's oak, Arizona fescue and mountain muhly.
DISTRIBUTION AND EXTENT: Southern Rocky Mountains, Colorado; LRR E, MLRA 48A; small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Las Animas County, Colorado, 2007, Las Animas Area soil survey area, Colorado.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Series control section: The zone from 13 to 32 inches.
Particle-size control section: The zone from 7 to 32 inches. (Bt/E, Bt1, and Bt2 horizons)
Ochric epipedon: The zone from 1 to 3 inches. (A horizon)
Glossic horizon: The zone from 7 to 13 inches. (Bt/E horizon)
Argillic horizon: The zone from 7 to 32 inches. (Bt/E, Bt1, and Bt2 horizons)
Paralithic contact: The contact with shale and siltstone at 32 inches. (Cr horizons)
Other features: Udic moisture regime bordering on ustic.
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomic Version: Eighth Edition, 1998