LOCATION NOPURG COEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, mixed, superactive Ustic Glossocryalfs
TYPICAL PEDON: Nopurg cobbly sandy loam, on a south facing, convex, 37 percent slope in mixed conifers at an elevation of 10,040 feet. (Colors are for dry soil unless otherwise noted.) When described on July 3, 1985 the soil was moist from 0 to 72 inches. The surface is covered by 5 percent stones and 5 percent cobbles.
Oi--0 to 1 inches; slightly decomposed plant material.
E--1 to 12 inches; pinkish gray (5YR 6/2) cobbly sandy loam, dark reddish gray (5YR 4/2) moist; weak fine granular structure; soft, very friable, nonsticky, and nonplastic; common fine, medium and coarse roots; 10 percent gravel, 10 percent cobbles, 5 percent stones, moderately acid (pH 5.8); clear smooth boundary. (6 to 12 inches thick)
B/E--12 to 24 inches; 60 percent reddish brown (5YR 5/3) very cobbly sandy clay loam, and 40 percent pinkish gray (5YR 6/2) very cobbly sandy loam, reddish brown (5YR 4/3) moist and crushed; weak fine subangular blocky structure; slightly hard, friable, slightly sticky, and slightly plastic; common fine and medium roots; 15 percent gravel, 25 percent cobbles, 2 percent stones; moderately acid (pH 5.9); clear smooth boundary. (6 to 12 inches thick)
Bt1--24 to 35 inches; reddish brown (2.5YR 5/3) very cobbly sandy clay, reddish brown (2.5YR 4/3) moist; moderate medium subangular blocky structure; very hard, firm, sticky and plastic; few fine and medium roots; common continuous clay films on faces of peds; 15 percent gravel, 35 percent cobbles, 2 percent stones; moderately acid (pH 5.7); clear smooth boundary. (8 to 12 inches thick)
Bt2--35 to 72 inches; weak red (10R 5/3) very cobbly clay, weak red (10R 4/3) moist; moderate medium subangular blocky structure; extremely hard, very firm, very sticky and very plastic; common patchy clay films on faces of peds; 10 percent gravel, 40 percent cobbles, 5 percent stones; moderately acid (pH 5.6).
TYPE LOCATION: Las Animas County, Colorado; about 8.5 miles east of Cucharas Pass on Cordova Pass road; located about 2,500 feet west and 2,400 feet south of the northeast corner of sec. 21, T. 31 S., R. 68 W.; Herlick Canyon USGS quad; lat. 37 degrees 20 minutes 2 seconds N. and long. 105 degrees 0 minutes 4 seconds W., NAD 1927
RANGE IN CHARACTERISTICS: (depths are from mineral soil surface)
Soil moisture: The soil moisture control section is moist continuously from March through September, driest December through February; Udic moisture regime bordering on ustic.
Mean annual soil temperature: 36 to 40 degrees F
Mean summer soil temperature: 44 to 48 degrees F
Thickness of the albic horizon: 6 to 12 inches
Depth to the base of the argillic horizon: 60 to 72 inches
Thickness of the glossic horizon: 6 to 12 inches
Particle-size control section (weighted average):
Clay content: 35 to 50 percent
Sand content: 35 to 55 percent
Rock fragments: 35 to 60 percent gravel and cobbles
E horizon:
Hue: 5YR to 10YR
Value: 6 to 8 dry, 4 to 6 moist
Chroma: 2 or 3
Clay content: 10 to 20 percent
Rock fragments: 35 to 60 percent
Reaction: strongly acid or moderately acid
B/E horizon:
Same properties as overlying E and underlying Bt horizons.
Bt horizons:
Hue: 10R to 5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 4
Texture of the fine earth fraction: sandy clay, clay
Clay content: 35 to 50 percent
Rock fragments: 35 to 60 percent
Base saturation: 60 to 100 percent
Reaction: moderately acid or slightly acid
COMPETING SERIES: This is the
Loberg(MT) series.
Loberg soils: have hues 7.5YR or yellower in the Bt horizons.
GEOGRAPHIC SETTING:
Parent material: slope alluvium and colluvium derived from mixed metamorphic and sedimentary rocks
Landform: mountain slopes
Slopes: 10 to 40 percent
Elevation: 8,500 to 10,500 feet
Mean annual temperature: 38 to 40 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 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Leadville and Mitotes series. The Leadville soils average less than 35 percent clay and are on mountain slopes. The Mitotes soils average less than 35 percent rock fragments 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 mainly Rocky Mountain Douglas fir, white fir, Engelmann's spruce with an understory of Arizona fescue, Parry's oatgrass, mountain brome, common juniper and kinninnick.
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, Colorado. The name is coined from North Purgatoire River.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 24 to 44 inches. (Bt1 and part of the Bt2 horizons)
Albic horizon: The zone from 1 to 12 inches. (E horizon)
Glossic horizon: The zone from 12 to 24 inches. (B/E horizon)
Argillic horizon: The zone from 24 to 72 inches. (Bt1 and Bt2 horizons)
Other features: This series separates the typic udic concept of the Nutras series from udic bordering on ustic identified in this series.
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomic Version: Tenth Edition, 2006.