LOCATION LEEVAN                  NV+OR

Established Series
Rev. PWB-RLB-JVC-JBF
04/2019

LEEVAN SERIES

The Leevan series consists of moderately deep, well drained soils that formed in residuum and colluvium derived from volcanic rocks or volcanoclastic sedimentary rocks. Leevan soils are on mountains and hills. Slopes are 4 to 60 percent. The mean annual precipitation is about 360 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Typic Argixerolls

TYPICAL PEDON: Leevan cobbly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with 20 percent gravel and 20 percent cobbles.

A1--0 to 13 cm; grayish brown (10YR 5/2) cobbly loam, very dark brown (10YR 2/2) moist; weak very thin and thin platy structure; soft, very friable, slightly sticky and slightly plastic; many fine roots; many fine and very fine interstitial pores; 10 percent gravel and 10 percent cobbles; neutral (pH 7.0); clear wavy boundary. (8 to 18 cm thick)

A2--13 to 23 cm; grayish brown (10YR 5/2) gravelly clay loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many fine roots; many fine and very fine interstitial pores; about 15 percent gravel; neutral (pH 7.0); clear wavy boundary. (8 to 18 cm thick)

Bt1--23 to 36 cm; brown (10YR 4/3) gravelly clay, dark yellowish brown (10YR 3/4) moist; strong medium prismatic structure parting to strong medium angular blocky; hard, firm, very sticky and very plastic; many fine roots; common fine interstitial and tubular pores; common prominent clay films on faces of peds and lining pores; organic matter coats on faces of peds in the upper part of horizon; about 25 percent gravel and 5 percent cobbles; neutral (pH 7.2); clear wavy boundary. (10 to 30 cm thick)

Bt2--36 to 61 cm; brown (10YR 4/3) very gravelly clay, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; hard, firm, very sticky and very plastic; common fine roots; common fine interstitial and tubular pores; common prominent clay films on faces of peds and lining pores; 40 percent gravel and 10 percent cobbles; slightly alkaline (pH 7.4); abrupt wavy boundary. (20 to 46 cm thick)

R--61 cm; hard rhyolite; fractured in the upper part.

TYPE LOCATION: Elko County, Nevada; between Twin Springs and Bailey Mountain; about 1,400 feet south and 2,360 feet east of the northwest corner of section 25, T. 28 N., R. 53 E.; USGS Bailey Mountain 7.5 minute topographic quadrangle; latitude 40 degrees 17 minutes 01 seconds N and longitude 115 degrees 56 minutes 38 seconds W; WGS84 Decimal Degrees 40.2836111 latitude, -115.9438889 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist from winter to early summer, dry from mid-July through October; xeric moisture regime that borders on aridic.
Mean annual soil temperature: 5 to 8 degrees C.
Mollic epipedon thickness: 18 to 36 cm; typically does not include the Bt1 horizon.
Depth to base of argillic horizon: 50 to 100 cm.
Depth to bedrock: 50 to 100 cm to a lithic contact.

Particle-size control section - Clay content: 40 to 50 percent.
Rock fragments: Average 35 to 50 percent, Lithology of fragments are volcanic rocks such as rhyolite, tuff, and basalt or volcanoclastic sedimentary rocks.

A horizons
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Structure: Platy, granular, or subangular blocky.
Organic matter content: 2 to 4 percent.

Bt1 horizon
Texture: Gravelly clay or very gravelly clay loam.
Clay content: 30 to 50 percent.
Rock fragments: 20 to 35 percent.
Other features: A stone line is commonly present between the A2 and Bt1 horizons.

Bt2 horizon
Hue: 7.5YR or 10YR.
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 3 through 6, dry or moist.
Clay content: 40 to 60 percent.
Rock fragments: Averages 35 to 55 percent, mainly gravel.
Reaction: Neutral or slightly alkaline.
Other features: Some pedons have a Bt3 horizon.

COMPETING SERIES: These are the Birchcreek, Derringer, Droem, McIvey, Ravenswood, Roostercomb, Sharesnout, Threek, Tickville, Urwil, Wilpar, Yago, and Yeates Hollow series.

Birchcreek, Ravenswood, and Sharesnout soils have a mollic epipedon that includes the upper part of the argillic horizon. Derringer soils are moderately deep to paralithic contacts. Droem soils average less than 40 percent clay in the particle-size control section. McIvey, Threek, Urwil, and Yago soils are very deep. Roostercomb soils have 60 to 70 percent rock fragments in the particle-size control section. Tickville soils have a typic xeric moisture regime. Wilpar soils are deep to paralithic contacts. Yeates Hollow soils are deep to lithic contacts.

GEOGRAPHIC SETTING: Leevan soils are on mountains and hills. They typically occur on convex shoulder, backslope, or footslope positions. These soils formed in residuum and colluvium derived from volcanic rocks (welded tuff, rhyolite, and basalt) or volcanoclastic sedimentary rocks (sandstone, shale, and conglomerate). Elevations range from 1,710 to 2,535 meters and are 1,740 to 1,925 meters near the Nevada-Idaho state line. Slopes are 4 to 60 percent. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 300 to 410 mm, the mean annual temperature is 4 to 7 degrees C, and the frost-free period is 50 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arcia, Cleavage, and Hackwood soils. Arcia soils are fine textured and have thick mollic epipedons. Cleavage soils are shallow to lithic contacts. Hackwood soils are very deep and do not have argillic horizons.

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

USE AND VEGETATION: Leevan soils are used for rangeland and wildlife habitat. The vegetation is mainly low sagebrush, bluebunch wheatgrass, Idaho fescue, Sandberg bluegrass, and lupine.

DISTRIBUTION AND EXTENT: Northeastern Nevada and south-central Oregon. These soils are moderately extensive. The series concept and main acreage is in MLRA 25 in Nevada, while other acreage occurs in MLRA 23 in Oregon.

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

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

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 23 cm (A1 and A2 horizons).
Argillic horizon - The zone from 23 to 61 cm (Bt1 and Bt2 horizons).
Lithic contact - The boundary at 61 cm to underlying hard, unweathered bedrock (R layer).
Particle-size control section - The zone from 23 to 61 cm (Bt1 and Bt2 horizons).

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National Cooperative Soil Survey
U.S.A.