LOCATION NUTRAS COEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic Eutric Glossocryalfs
TYPICAL PEDON: Nutras stony loam - forest. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 3 inches; slightly decomposed organic material, mainly needles, barks, twigs, and leaves.
Oe--3 to 4 inches; partially decomposed organic material like that of the horizon above.
E--4 to 13 inches; very pale brown (10YR 8/2) stony loam, very pale brown (10YR 7/3) moist; moderate thin platy structure parting to very fine granules; soft, very friable, slightly sticky and slightly plastic; 30 percent stones; strongly acid; gradual smooth boundary. (6 to 12 inches thick)
E/B--13 to 19 inches; pinkish gray (5YR 7/2) and reddish brown (5YR 5/4) stony clay loam, reddish gray (5YR 5/2) and reddish brown (5YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; peds are hard, friable; few faint clay films on the more clayey peds; clayey material like that of the underlying horizon imbedded in a light colored matrix like that of the overlying horizon; many dark gray magnetic ferromagnesium- rich mineral grains and fragments of basalt in the sand and silt fractions; 30 percent stones; strongly acid; gradual wavy boundary. (6 to 12 inches thick)
Bt1--19 to 36 inches; reddish brown (5YR 5/4) very stony clay, reddish brown (5YR 4/4) moist; strong medium and fine angular and subangular blocky structure; slightly hard, very friable, sticky and plastic; peds are extremely hard, firm; many distinct clay films on ped faces and in root channels and pores; many dark gray magnetic mineral grains and fragments of basalt of sand and silt size; 60 percent stones; moderately acid; gradual wavy boundary. (12 to 28 inches thick)
Bt2--36 to 44 inches; reddish brown (5YR 5/4) extremely stony clay, reddish brown (5YR 4/4) moist; weak coarse subangular blocky structure; hard, friable, sticky and plastic; peds are extremely hard, very firm; few faint clay films on peds and in some root channels and pores; many dark gray mineral grains and fragments of basalt of sand and silt size; 70 percent stones; slightly acid; gradual wavy boundary. (8 to 10 inches thick)
C--44 to 64 inches; reddish brown (5YR 5/4) extremely stony clay, reddish brown (5YR 4/4) moist; massive; extremely hard, very firm, sticky and plastic; many dark gray mineral grains and fragments of basalt of sand and silt size; 70 percent stones; slightly acid.
TYPE LOCATION: Hinsdale County, Colorado; N1/2 Sec. 33, T. 45 N., R. 2 W.
RANGE IN CHARACTERISTICS: Depths are from the mineral soil surface.
Soil moisture: udic moisture regime.
Mean annual soil temperature is 38 degrees F
Mean summer soil temperature is 44 degrees F. with thick O horizons.
Depth to carbonates: more than 40 inches.
Base saturation: 60 to 100 percent in all subhorizons of the argillic horizon.
Depth to the top of the argillic horizon: is less than 24 inches.
Rock fragment content: 35 to 80 percent in the control section and any C horizon and are mainly 10 to 36 inches in diameter but includes gravel and cobble as well.
Sand and silt fractions contain 5 to 20 or more percent dark colored ferromagnesium-rich minerals or fragments of basalt.
Reaction: moderately acid to slightly alkaline.
The A horizon, if present:
Hue: 10YR through 5YR
Value: 4 or 5 dry, 2 through 4 moist
Chroma: 1 through 3
Reaction: slightly acid or moderately acid.
The E horizon:
Hue: 10YR through 5YR
Value: 5 through 8 dry, 4 through 7 moist
Chroma: 1 through 4
Reaction: slightly acid to strongly acid
Textures: sandy loam, loam, clay loam frequently modified by rock fragments.
E/B has the same properties as the E and Bt horizons
The Bt horizon:
Hue: of 5YR through 10R
Value: 5 through 7 dry, 4 through 6 moist
Chroma: 1 through 6
Texture: clay loam, clay, or sandy clay modified by 35 to 80 percent rock fragments
Clay content: 35 to 50 percent
Silt content: 5 to 45 percent
Sand content: 15 to 55 percent with more than 15 percent being fine or coarser sand.
Reaction is neutral to moderately acid.
The C horizon, if present:
Hue: 5YR through 10R
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 through 6
Texture: clay loam or clay modified by 35 to 80 percent rock fragments.
Clay content: more than 35 percent clay to a depth of at least 55 inches.
COMPETING SERIES: This is the
Chris (CO) series.
Chris soils: formed in slope alluvium from sedimentary rocks and lack dark colored ferro-magnesium rich minerals or basalt fragments in the sand and silt fraction.
GEOGRAPHIC SETTING:
Landform: mesas, ridges, benches, mountain slopes, basaltic lava flows, alluvial fans, and valley sideslopes.
Slopes: 2 to 65 percent.
Parent material: fine textured stony parent material weathered primarily from basalt and other igneous rocks.
Elevation ranges from 8,500 to 11,500 feet.
Mean annual precipitation ranges from 26 to 35 inches with peak periods of precipitation during the spring and summer.
Mean annual temperature ranges 32 to 40 degrees F., and mean summer temperature is 43 degrees F.
Frost-free period is 40 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Sapinero soils and the competing Vulcan soils. Sapinero soils have argillic horizons with less than 35 percent clay and overlie fragmental 2C horizons.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; slow permeability.
USE AND VEGETATION: These soils are used for forestry, as native pastureland, and for recreational purposes. Native vegetation consists of Engelmann's spruce, subalpine fir, and a scattered understory of grasses and shrubs.
DISTRIBUTION AND EXTENT: Mountainous areas of Colorado. LRR E, MLRA 48A; The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Hinsdale County, Colorado, 1974.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Albic horizon: the zone from 4 to 13 inches (E horizon).
Glossic horizon: the zone from 13 to 19 inches (E/B horizon).
Argillic horizon: the zone from 19 to 40 inches (Bt1 and Bt2 horizons).
4/2001 the classification was changed from Ustic to Eutric Glosscryalfs. Precipitation range was narrowed to exclude the less than 26 inches to limit this series to the typic-udic moisture regime.