LOCATION COLBAR NV
Established Series
Rev. JBF/WED/RLB
05/2016
COLBAR SERIES
The Colbar series consists of moderately deep, well drained soils that formed in residuum and colluvium derived from rhyolitic and andesitic rocks. Colbar soils are on mountains and hills. Slopes are 8 to 50 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 9 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Xeric Haplargids
TYPICAL PEDON: Colbar cobbly loam-rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 8 cm; brown (10YR 5/3) cobbly loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; few very fine interstitial and tubular pores; 5 percent gravel, 25 percent cobbles and 1 percent stones; slightly alkaline (pH 7.4); clear smooth boundary. (5 to 10 cm thick)
A2--8 to 15 cm; pale brown (10YR 6/3) cobbly loam, brown (10YR 4/3) moist; moderate fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots; few very fine and fine tubular pores; 5 percent gravel and 20 percent cobbles; slightly alkaline (pH 7.4); clear smooth boundary. (0 to 18 cm thick)
BA--15 to 23 cm; pale brown (10YR 6/3) cobbly loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, moderately sticky and slightly plastic; common very fine and fine roots; common fine tubular pores; 5 percent gravel and 15 percent cobbles; slightly alkaline (pH 7.4); clear smooth boundary. (0 to 18 cm thick)
Bt1--23 to 30 cm; yellowish brown (10YR 5/4) cobbly loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; soft, very friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine tubular pores; few thin clay films on faces of peds, lining pores and coating rock fragments; 5 percent gravel and 15 percent cobbles; moderately alkaline (pH 8.4); clear wavy boundary.
Bt2--30 to 41 cm; pale brown (10YR 6/3) cobbly loam, brown (10YR 4/3) moist; strong fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common fine tubular pores; few thin clay films lining pores and coating rock fragments; 15 percent gravel and 15 percent cobbles; moderately alkaline (pH 8.4); clear smooth boundary. (combined thickness of Bt horizons is 10 to 53 cm)
C--41 to 53 cm; pale brown (10YR 6/3) gravelly loam; brown (10YR 4/3) moist; massive; soft, very friable, slightly sticky and slightly plastic; few fine roots; few fine tubular pores, 10 percent gravel and 5 percent cobbles; moderately alkaline (pH 8.4); abrupt irregular boundary. (0 to 40 cm thick)
R--53 cm; hard fractured rhyolite with pockets of loam and few fine roots.
TYPE LOCATION: Churchill County, Nevada; 2,500 feet north and 1,200 feet west of the southeast corner of section 18, T. 18 N., R. 37 E., latitude 39 degrees 25 minutes 29 seconds N and longitude 117 degrees 51 minutes 18 seconds W; WGS84 Decimal Degrees 39.4247222 latitude, -117.8550000 longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Dry during summer and autumn, moist in late winter and spring, typic aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 9 to 11 degrees C.
Depth to bedrock: 50 to 100 cm.
Thickness of A and Bt horizons: 28 to 60 cm.
Other features: Some pedons have Bk horizons with thin lime coats on undersides of rock fragments below the Bt horizon.
Particle-size control section - Clay content: 25 to 35 percent.
Rock fragments: 15 to 35 percent, mainly gravel and cobbles.
A horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3.
Reaction: Slightly alkaline or moderately alkaline.
Bt horizon
Value: 5 or 6 dry, 3 through 5 moist.
Chroma: 3 or 4.
Structure: Weak to strong, very fine to medium subangular blocky.
Consistence: Soft to hard, very friable to friable.
Texture: Cobbly loam, cobbly clay loam or gravelly clay loam.
Reaction: Slightly alkaline or moderately alkaline.
C or Bk horizon (when present)
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 3 or 4.
Texture: Gravelly loam or cobbly loam.
COMPETING SERIES: These are
Abgese,
Ackley,
Blacknest, Bluelight,
Eusbio,
Greenbrae,
Hardtrigger,
Harsan,
Hoosegow,
Hoye,
Lankbush,
Morfitt,
Nosser,
Shawave,
Sidlake,
Turria and
Windypoint soils.
Abgese,
Ackley,
Blacknest, Bluelight,
Eusbio,
Greenbrae,
Hardtrigger,
Harsan,
Hoosegow,
Hoye,
Lankbush,
Morfitt,
Shawave,
Sidlake,
Turria and
Windypoint soils lack bedrock within 100 cm.
Nosser soils have a discontinuity in the lower argillic horizon with common silica durinodes.
GEOGRAPHIC SETTING: Colbar soils are on mountains and hills. The soils formed in residuum and colluvium from rhyolitic and andesitic rocks. Elevations are 1,453 to 2,195 meters. Slopes range from 8 to 50 percent. The climate is cool, semiarid. The mean annual precipitation of 200 to 250 mm; average annual temperature is 8 to 10 degrees C, and the frost-free season is 100 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Jung and
Old Camp soils. Jung and Old Camp soils are less than 50 cm deep.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium to rapid runoff; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: Wyoming Big sagebrush, desert needlegrass, ephedra and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: Foothills in central Nevada. Colbar soils are of small extent. MLRA 27, 24, 28B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Lander County, Nevada, South Part, 1985.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the surface to 23 cm (A1, A2 and AB horizons).
Argillic horizon - The zone from 23 to 41 cm (Bt1 and Bt2 horizons).
Lithic contact - The boundary at 53 cm (R layer).
Particle-size control section - The zone from 23 to 41 cm (Bt1 and Bt2 horizons).
National Cooperative Soil Survey
U.S.A.