LOCATION COLTROOP NVEstablished Series
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 2 inches; 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 pores; 5 percent pebbles; mildly alkaline (pH 7.4); clear smooth boundary. (2 to 3 inches thick).
A2--2 to 5 inches; 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 pebbles; mildly alkaline (pH 7.4); abrupt wavy boundary. (2 to 4 inches thick).
Bw--5 to 10 inches; 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 pebbles; mildly alkaline (pH 7.6); abrupt wavy boundary. (5 to 11 inches thick).
Bqk--10 to 17 inches; 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; few medium pebbles; weakly cemented with silica and lime; 40 percent durinodes; slightly effervescent; mildly alkaline (pH 7.8); abrupt wavy boundary. (2 to 8 inches thick).
2Bqkm--17 to 27 inches; 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. (9 to 10 inches thick).
2Ck--27 to 32 inches; very pale brown (10YR 7/4) sandy loam, yellowish brown (10YR 5/4) moist; massive; loose, nonsticky and nonplastic; common very fine roots; 10 percent pebbles; violently effervescent lime is disseminated; moderately alkaline (pH 8.4); abrupt wavy boundary (0 to 5 inches thick).
3R--32 inches; rhyolite.
TYPE LOCATION: Elko County, Nevada; approximately 4.75 miles northeast of Lake Creek Reservoir, near the Little Owyhee River in a unsectionized area, 41 degrees, 59 minutes, 22 seconds north latitude and 116 degrees, 52 minutes, 12 seconds west longitude.
RANGE IN CHARACTERISTICS:
Soil moisture - Moist in winter and spring, dry June through October.
Soil temperature - 47 to 52 degrees F.
Depth to duripan - 14 to 20 inches.
Depth to bedrock - 30 to 35 inches.
Depth to Bqk horizon - 10 to 16 inches.
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: Mildly alkaline or moderately alkaline.
Bqkm horizon - Structure: Thick platy or is massive.
COMPETING SERIES: These are the Arritola (OR), Besslen (T)(ID), Chiara (NV), Crooked (OR), Frohman (OR), Minveno (ID), Nevoyer (NV), Otoole (OR), Peeko (NV), Plegomir (UT) Scoon (WY)and Tenvorrd (NV) and Yahoo (T)(ID)series. All of these soils except the Nevoyer soils do not have bedrock within a depth of 40 inches. The Nevoyer soils are 9 to 20 inches deep to bedrock.
GEOGRAPHIC SETTING: Coltroop soils are on plateaus and fan piedmont remnants with a rock core. These soils formed in a thin loess mantle over alluvium from rhyolite and basalt. Slopes are 0 to 4 percent. Elevations are 5,100 to 5,500 feet. The climate is cool, semiarid with cold, moist winters and warm dry summers. The mean annual precipitation is 8 to 10 inches; mean annual temperature is 45 to 50 degrees F., 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 60 inches deep. Snowmore soils are 20 to 30 inches deep to the duripan and have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained. Very slow or slow runoff; moderately slow permeability.
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 OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Northwest Elko County Area, Nevada, 1986.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Cambic horizon - The zone from about 5 to 10 inches (Bw horizon).
Indurated duripan - The zone from about 17 to 27 inches (Bqkm horizon).
Lithic contact - The boundary at about 32 inches (3R horizon).
Particle-size control section - The zone from about 10 to 17 inches (Bqk horizon).
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.