LOCATION COLTROOP NV
Established Series
Rev. TSB/GJS/RLB/JBF
01/2019
COLTROOP SERIES
The Coltroop series consists of shallow, well drained soils that formed in a loess mantle over alluvium derived from rhyolite and basalt. The Coltroop soils are on plateaus and rock pediments. Slopes are 0 to 4 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 8 degrees C.
TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Xeric Haplodurids
TYPICAL PEDON: Coltroop very fine sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 5 cm; light brownish gray (10YR 6/2) very fine sandy loam, dark grayish brown (10YR 4/2) moist; weak medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine and very fine roots; common medium, many fine and very fine vesicular pores; 5 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary. (5 to 8 cm thick)
A2--5 to 13 cm; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; weak thin platy structure parting to moderate fine granular; slightly hard, very friable, slightly sticky and slightly plastic; few medium, many fine and very fine roots; few fine tubular pores; 5 percent gravel; slightly alkaline (pH 7.4); abrupt wavy boundary. (5 to 10 cm thick)
Bw--13 to 25 cm; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common medium, fine and very fine roots; few fine tubular pores; 5 percent gravel; slightly alkaline (pH 7.6); abrupt wavy boundary. (13 to 28 cm thick)
Bqk--25 to 43 cm; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; 5 percent medium gravel; weakly cemented with silica and carbonates; 40 percent durinodes; slightly effervescent; slightly alkaline (pH 7.8); abrupt wavy boundary. (5 to 20 cm thick)
2Bqkm--43 to 69 cm; very pale brown (10YR 8/4) continuous indurated duripan; very pale brown (10YR 7/4) moist; strong thick platy structure; extremely hard, very firm; few very fine roots along plate surfaces; violently effervescent; abrupt wavy boundary. (23 to 25 cm thick)
2Ck--69 to 81 cm; very pale brown (10YR 7/4) sandy loam, yellowish brown (10YR 5/4) moist; single grain; loose, nonsticky and nonplastic; common very fine roots; 10 percent gravel; violently effervescent, carbonates are disseminated; moderately alkaline (pH 8.4); abrupt wavy boundary (0 to 13 cm thick)
3R--81 cm; rhyolite.
TYPE LOCATION: Elko County, Nevada; approximately 4.75 miles northeast of Lake Creek Reservoir, near the Little Owyhee River. About 2,100 feet north and 1,775 feet east of the northeast corner of section 7, T. 47 N., R. 46 E.; USGS Star Velley Ridge East 7.5 minute topographic quadrangle; latitude 41 degrees 59 minutes 22 seconds N and longitude 116 degrees 52 minutes 12 seconds W; WGS84 Decimal Degrees 41.9894444 latitude, -116.8700000 longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Moist in winter and spring, dry June through October; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Depth to duripan: 36 to 50 cm.
Depth to bedrock: 76 to 89 cm.
Depth to Bqk horizon: 25 to 41 cm.
Particle-size control section - Clay content: 20 to 30 percent.
Rock fragments: 0 to 15 percent.
A horizon
Chroma: 2 or 3.
Bw horizon
Chroma: 3 or 4.
Clay content: 18 to 27 percent.
Bqk horizon
Value: 4 or 5 moist.
Chroma: 3 or 4.
Texture: Silt loam or silty clay loam.
Clay content: 20 to 30 percent.
Durinodes: 20 to 40 percent.
Reaction: Slightly alkaline or moderately alkaline.
Bqkm horizon
Structure: Thick platy or is massive.
COMPETING SERIES: These are the
Arritola,
Besslen,
Chiara,
Frohman,
Minveno,
Nevoyer,
Otoole,
Peeko,
Plegomir,
Scoon,
Tenvorrd and
Yahoo series.
Arritola,
Besslen,
Chiara,
Frohman,
Minveno,
Otoole,
Peeko,
Plegomir,
Scoon,
Tenvorrd and
Yahoo soils do not have bedrock within a depth of 100 cm. The
Nevoyer soils are 23 to 50 cm deep to bedrock.
GEOGRAPHIC SETTING: Coltroop soils are on plateaus and rock pediments. These soils formed in a thin loess mantle over alluvium from rhyolite and basalt. Slopes are 0 to 4 percent. Elevations are 1,555 to 1,680 meters. The climate is cool, semiarid with cold, moist winters and warm dry summers. The mean annual precipitation is 200 to 250 mm, mean annual temperature is 7 to 10 degrees C, and the frost-free season is 100 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Bartome,
Snowmore and
Wedertz soils. Bartome and Wedertz soils are more than 150 cm deep. Snowmore soils are 50 to 79 cm deep to the duripan and have an argillic horizon.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. Very slow or slow runoff; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly Wyoming big sagebrush and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: Northeastern Nevada. MLRA 25. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Northwest Elko County Area, Nevada, 1986.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the surface to 18 cm (A1, A2, and part of the Bw horizons.
Cambic horizon - The zone from 13 to 25 cm (Bw horizon).
Indurated duripan - The zone from 43 to 69 cm (2Bqkm horizon).
Lithic contact - The boundary at 81 cm (3R horizon).
Particle-size control section - The zone from 25 to 43 cm (Bqk horizon).
National Cooperative Soil Survey
U.S.A.