LOCATION LITTLEWATER COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Paleustalfs
TYPICAL PEDON: Littlewater very gravelly silt loam, on a northwest facing, 85 percent slope in Douglas Fir woodland at an elevation of 8350 feet. (Colors are for dry soil unless otherwise noted.) When described on Aug. 26, 2002 the soil was dry throughout. The surface is covered by 1 inch of needles and twigs.
Oe--0 to 1 inches; moderately decomposed plant material; 1 percent stones and 10 percent cobbles and 30 percent gravel; noneffervescent; abrupt smooth boundary. (1 to 4 inches thick)
A--1 to 7 inches; dark brown (10YR 3/3) very gravelly silt loam, very dark grayish brown (10YR 3/2) moist; moderate very fine granular structure; soft, very friable, slightly sticky, slightly plastic; common very fine roots throughout; 15 percent clay; 30 percent gravel and 10 percent cobbles and 1 percent stones; noneffervescent; neutral (pH 7.2); clear smooth boundary. (1 to 8 inches thick)
AE--7 to 20 inches; dark yellowish brown (10YR 4/4) very gravelly loam, dark yellowish brown (10YR 3/4) moist; weak medium platy structure parting to moderate fine granular; slightly hard, very friable, slightly sticky, slightly plastic; common fine, common medium, and common very fine roots throughout; 25 percent gravel and 10 percent cobbles and 1 percent stones; noneffervescent; neutral (pH 7.0); clear smooth boundary. (5 to 20 inches thick)
E--20 to 31 inches; yellowish brown (10YR 5/4) very gravelly loam, brown (10YR 5/3) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine, fine, medium, and coarse roots throughout; few very fine dendritic tubular pores; 12 percent clay; 35 percent gravel and 15 percent cobbles and 1 percent stones; noneffervescent; neutral (pH 6.8); clear smooth boundary. (8 to 20 inches thick)
Bt1--31 to 51 inches; strong brown (7.5YR 5/6) very gravelly loam, strong brown (7.5YR 4/6) moist; moderate medium subangular blocky structure; moderately hard, friable, moderately sticky, moderately plastic; common very fine, fine, medium, and coarse roots throughout; common very fine dendritic tubular pores; 30 percent discontinuous distinct clay films on all faces of peds; 35 percent gravel and 15 percent cobbles and 1 percent stones; noneffervescent; neutral (pH 6.8); gradual smooth boundary. (10 to 30 inches thick)
Bt2--51 to 80 inches; strong brown (7.5YR 4/6) very gravelly loam, strong brown (7.5YR 4/6) moist; moderate medium subangular blocky structure; moderately hard, friable, moderately sticky, moderately plastic; common very fine, fine, medium, and coarse roots throughout; common very fine dendritic tubular pores; 50 percent discontinuous distinct clay films on all faces of peds; 16 percent clay; 35 percent gravel and 15 percent cobbles and 1 percent stones; noneffervescent; neutral (pH 6.8).
TYPE LOCATION: Montezuma County, Colorado; about 7 miles west of Towaoc; located about 2000 feet east and 1600 feet north of the southwest corner of sec. 34, T. 35 N., R. 18 W.; Mariano Wash East, Colorado USGS quad; lat. 37 degrees 14 minutes 41.05 seconds N. and long. 108 degrees 49 minutes 13.54 seconds W., NAD 83
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is udic ustic.
Mean annual soil temperature: 44 to 47 degrees F
Depth to argillic horizon: 20 to 35 inches
Particle-size control section (weighted average):
Clay content: 10 to 20 percent
Rock fragment content: 35 to 80 percent, predominantly gravel and cobble
A horizon:
Hue: 10YR
Value: 3 or 4
Chroma: 2 through 4
Texture, fine earth fraction: sandy loam or silt loam
Rock fragment content: 35 to 80 percent, predominantly gravel and cobble
Clay content: 10 to 15 percent
Reaction: Slightly acid or neutral
E horizon:
Hue: 10YR
Value: 4 through 6
Chroma: 3 through 5
Texture, fine earth fraction: sandy loam or loam
Rock fragment content: 35 to 80 percent, predominantly gravel and cobble
Clay content: 5 to 15 percent
Reaction: Slightly acid or neutral
Bt horizon:
Hue: 10YR or 7.5YR
Value: 4 or 5
Chroma: 4 to 6
Texture, fine earth fraction: sandy loam or loam
Rock fragment content: 35 to 80 percent, predominantly gravel and cobble
Clay content: 10 to 20 percent
Reaction: Slightly acid or neutral
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Parent material: Colluvium and slope alluvium derived from diorite and other intrusive igneous rock
Landform: Mainly steep, north facing mountain slopes
Slopes: 25 to 90 percent
Elevation: 7,500 to 9,500 feet
Mean annual temperature: 42 to 45 degrees F
Mean annual precipitation: 16 to 20 inches
Precipitation pattern: Uniform with slight dip in May and June and slight increase in July and August.
Frost-free period: 80 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Towaoc (T), Nees (T), and Wetoe (T) series. Towaoc soils lack E horizons and are formed under Gambel oak. The Nees soils are shallow and are on ridges and mountain summits and are on dryer sites. Wetoe are very deep and at lower elevations and dryer sites.
DRAINAGE AND PERMEABILITY: Well drained, moderate runoff, moderately rapid permeability.
USE AND VEGETATION: The area is used for watersheds and wildlife habitat. Potential native vegetation is mainly Rocky Mountain Douglas fir, Gambel oak, Utah serviceberry, common chokecherry, kinnikinnick, Letterman needlegrass, and mountain brome.
DISTRIBUTION AND EXTENT: Sleeping Ute Mountain, southwest Colorado; MLRA 36; small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Montezuma County, Colorado; Ute Mountain Area, Colorado and New Mexico, 2005. The name is from a nearby spring.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Series control section: The zone from 0 to 79 inches.
Particle-size control section: The zone from 31 to 51 inches. (Bt1 horizon)
Ochric epipedon: The zone from 0 to 20 inches. (A and AE horizons)
Argillic horizon: The zone from 31 to 80 inches. (Bt1 and Bt2 horizons)
Pale Great Group: 7.5YR or redder hues and less than 20% relative clay decrease in the argillic horizon within 150 cm of surface.
These soils are located in isolated, steep north facing areas on Ute Mountain and are cooler and have more effective moisture than neutral aspects at the same elevations and precipitation.
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003.