LOCATION ONKEYO                  NV

Established Series
Rev. DWW-RLB-JVC-JBF
11/2016

ONKEYO SERIES

The Onkeyo series consists of shallow, well drained soils that formed in residuum and colluvium derived from limestone and dolomite. Onkeyo soils are on mountains and hills. Slopes are 4 to 75 percent. The mean annual precipitation is about 400 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, active, frigid Lithic Calcixerolls

TYPICAL PEDON: Onkeyo very gravelly silty clay loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil is partially covered with 60 percent gravel, 5 percent cobbles, and 2 percent stones.

A1--0 to 8 cm; brown (10YR 5/3) very gravelly silty clay loam, dark brown (10YR 3/3) moist; weak very fine granular structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine roots; many very fine and few fine tubular pores; 40 percent gravel and 5 percent cobbles; common distinct secondary calcium carbonate coats on bottom of rock fragments; violently effervescent (4 percent calcium carbonate equivalent); slightly alkaline (pH 7.8); clear wavy boundary. (5 to 13 cm thick)

A2--8 to 20 cm; brown (10YR 5/3) very gravelly silty clay loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine and few fine roots; many very fine and few fine tubular pores; 35 percent gravel and 10 percent cobbles; common distinct secondary calcium carbonate coats on bottom of rock fragments; violently effervescent (6 percent calcium carbonate equivalent); slightly alkaline (pH 7.8); clear wavy boundary. (8 to 18 cm thick)

Bk--20 to 38 cm; light yellowish brown (10YR 6/4) extremely cobbly silty clay loam, yellowish brown (10YR 5/4) moist; weak medium angular blocky structure; very hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; many very fine and common fine tubular pores; 20 percent gravel, 40 percent cobbles, and 5 percent stones; common distinct secondary calcium carbonate coats on the bottom of rock fragments; violently effervescent (22 percent calcium carbonate equivalent); moderately alkaline (pH 8.0); abrupt irregular boundary. (15 to 23 cm thick)

R--38 cm; hard fractured limestone.

TYPE LOCATION: Elko County, Nevada; about 24 miles north of Wells in the Snake Mountains; approximately 1,400 feet south and 1,500 feet west of the northeast corner of section 15, T. 41 N., R. 61 E.; USGS Black Butte NE 7.5 minute topographic quadrangle; latitude 41 degrees 26 minutes 49 seconds N and longitude 115 degrees 03 minutes 21 seconds W; WGS84 Decimal Degrees 41.4469444 latitude, -115.0558333 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist from late fall through spring, dry mid-July through October; xeric soil moisture regime.
Mean annual soil temperature: 6 to 8 degrees C.
Mollic epipedon thickness: 18 to 25 cm.
Depth to calcic horizon: 18 to 25 cm.
Depth to bedrock: 36 to 50 cm to a lithic contact.
Reaction: Slightly alkaline through strongly alkaline.

Particle-size control section - Clay content: 25 to 35 percent.
Rock fragments: 50 to 80 percent, mainly cobbles. Lithology of fragments is mainly limestone and dolostone.

A horizons
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Effervescence: Slightly effervescent to violently effervescent.
Organic matter content: 2 to 4 percent.
Calcium carbonate equivalent: 1 to 10 percent.

Bk horizon
Value: 6 or 7 dry, 3 through 5 moist.
Chroma: 3 or 4, dry or moist.
Texture: Very cobbly silty clay loam or extremely cobbly silty clay loam.
Clay content: 25 to 35 percent.
Rock fragments: 50 to 80 percent.
Structure: Weak or moderate subangular blocky or angular blocky.
Consistence: Slightly hard to very hard dry, very friable friable to firm moist, slightly sticky or moderately sticky, and slightly plastic or moderately plastic.
Calcium carbonate equivalent: 15 to 25 percent.
Identifiable secondary carbonates: Occurs as coats on bottoms of rock fragments.

COMPETING SERIES: There are currently no other series in this family.

GEOGRAPHIC SETTING: Onkeyo soils are on mountains and hills. They typically occur on shoulder and backslope positions. These soils formed in residuum and colluvium derived from limestone and dolomite. Slopes are 4 to 75 percent. Elevations range from 1,830 to 2,750 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 330 to 460 mm, mean annual temperature is 5 to 7 degrees C, and the frost-free period is 70 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Amene and Belsac soils. Amene soils have a Bk horizon with 40 to 60 percent calcium carbonate equivalent. Belsac soils have a 50 to 76 cm thick mollic epipedon, are moderately deep to bedrock, and have summer soil temperatures of 13 to 15 degrees C.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; very high surface runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Onkeyo soils are used for livestock grazing and wildlife habitat. The present vegetation is mainly antelope bitterbrush, snowberry, mountain big sagebrush, serviceberry, bluebunch wheatgrass, Idaho fescue, and basin wildrye.

DISTRIBUTION AND EXTENT: Northeastern Nevada. These soils are moderately extensive. MLRAs 25 and 28B.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Elko County (Northeast Part), Nevada, 1986.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 20 cm (A1 and A2 horizons).
Calcic horizon - The zone from 20 to 38 cm (Bk horizon).
Lithic contact - The boundary at 38 cm to underlying hard bedrock (R layer).
Particle-size control section - The zone from 25 to 38 cm (part of the Bk horizon).

---

National Cooperative Soil Survey
U.S.A.