LOCATION EPVIP                   NV+CA

Established Series
Rev. JVC-JBF
03/2017

EPVIP SERIES

The Epvip series consists of shallow, well drained soils that formed in eolian volcanic ash over residuum and colluvium derived from andesite and tuff-breccia. Epvip soils are on mountains and hills. Slopes are 4 to 50 percent. The mean annual precipitation is about 360 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Ashy-skeletal, glassy, frigid, shallow Vitrandic Argixerolls

TYPICAL PEDON: Epvip gravelly ashy sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with 15 percent gravel and 3 percent cobbles.

A1--0 to 8 cm; grayish brown (10YR 5/2) gravelly ashy sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine interstitial and few very fine tubular pores; 15 percent gravel; neutral (pH 6.8); clear smooth boundary. (5 to 10 cm thick)

A2--8 to 13 cm; brown (10YR 5/3) gravelly ashy sandy loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine roots; common very fine tubular and few very fine interstitial pores; 15 percent gravel; neutral (pH 6.8); clear wavy boundary. (5 to 10 cm thick)

A3--13 to 20 cm; brown (10YR 5/3) gravelly ashy sandy loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine tubular and few very fine interstitial pores; 25 percent gravel; neutral (pH 6.8); clear irregular boundary. (0 to 8 cm thick)

Bt1--20 to 28 cm; brown (10YR 5/3) very gravelly ashy sandy clay 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 and fine roots; common very fine tubular and few very fine interstitial pores; 35 percent gravel; common faint and few distinct clay films on faces of peds; neutral (pH 6.8); clear irregular boundary. (8 to 18 cm thick)

Bt2--28 to 48 cm; light yellowish brown (10YR 6/4) very gravelly ashy sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine tubular pores; 35 percent gravel and 10 percent cobbles; many distinct clay films on faces of peds; neutral (pH 6.8); clear wavy boundary. (10 to 23 cm thick)

Cr--48 to 76 cm; weathered altered andesitic rock.

R--76 cm; hard fractured andesitic rock.

TYPE LOCATION: Mineral County, Nevada; about 2 miles south of Aurora; approximately 1,320 feet west and 660 feet south of the northeast corner of section 32, T. 5 N., R. 28 E.; USGS Kirkwood Spring 7.5 minute topographic quadrangle; latitude 38 degrees 14 minutes 51 seconds N and longitude 118 degrees 52 minutes 46 seconds W; WGS84 Decimal Degrees 38.2475000 latitude, -118.8794444 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter, spring, and early summer; dry in summer and fall, but moist intermittently in the surface horizons due to summer convection storms; xeric moisture regime that borders on aridic.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 36 cm; includes the Bt1 horizon and may include the Bt2 horizon in some pedons.
Depth to base of argillic horizon: 36 to 50 cm.
Depth to bedrock: 36 to 50 cm to a paralithic contact. The paralithic materials below the contact are weathered andesitic rock. Hard bedrock is typically within 80 cm of the soil surface.
Reaction - Slightly acid or neutral.

Particle-size control section - Clay content: 25 to 35 percent.
Rock fragments: 35 to 50 percent, mainly gravel over 50 percent of which are larger than 5 mm. in diameter. Lithology of fragments is volcanic rock such as andesite.

A horizons
Value: Dominantly 5 dry, but may be 6 in the upper part of the A1 horizon.
Chroma: 2 or 3, dry or moist.
Organic matter content: 2 or 3 percent.
Volcanic glass content: 30 to 75 percent in coarse silt through fine sand fractions.

Bt1 horizon
Hue: 7.5YR or 10YR.
Chroma: 2 or 3, dry or moist.
Texture: Very gravelly ashy sandy clay loam, very gravelly ashy clay loam, or very gravelly ashy loam.
Clay content: 25 to 35 percent.
Rock fragments: 35 to 50 percent.
Organic matter content: 1 or 2 percent.
Volcanic glass content: 30 to 70 percent in coarse silt through fine sand fractions.

Bt2 horizon
Chroma: 3 or 4, dry or moist.
Texture: Very gravelly ashy sandy clay loam, very gravelly ashy clay loam, or very gravelly ashy loam.
Clay content: 25 to 35 percent.
Rock fragments: 35 to 50 percent.
Organic matter content: 0.5 to 2 percent.
Volcanic glass content: 30 to 60 percent in coarse silt through fine sand fractions.

Bt3 and Bt4 horizons (when present)
Hue: 7.5YR or 10YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Very gravelly ashy sandy clay loam, very gravelly ashy clay loam, or very gravelly ashy loam.
Clay content: 25 to 35 percent.
Rock fragments: 35 to 50 percent.
Organic matter content: 0.5 to 1 percent.
Volcanic glass content: 30 to 60 percent in coarse silt through fine sand fractions.

COMPETING SERIES: These are the Adamatt, Crazybird, Dawgbuffer and Rancheria series.

Adamatt and Rancheria soils average less than 18 percent clay in the particle-size control section. Crazybird soils average 18 to 26 percent clay in the particle-size control section and have mollic epipedons 36 to 50 cm thick. Dawgbuffer soils average 15 to 25 percent clay in the particle-size control section and are 18 to 36 cm to bedrock.

GEOGRAPHIC SETTING: Epvip soils are on mountains, hills and backslopes. These soils formed in eolian volcanic ash over residuum and colluvium derived from andesite and tuff-breccia. The probable sources of the volcanic ash are the Mono Craters and Long Valley Caldera in eastern California. Slopes are 4 to 50 percent. Elevations range from 1,195 to 2,840 meters. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 360 to 400 mm, the mean annual temperature is 6 to 7 degrees C., and the frost-free period is 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hiridge, Katyblay, and Nire soils. Hiridge soils have a cryic temperature regime. Katyblay soils are very deep, have ochric epipedons, and a cryic temperature regime. Nire soils are very deep, have thick mollic epipedons, and a cryic temperature regime.

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

USE AND VEGETATION: Epvip soils are used for rangeland and wildlife habitat. The present vegetation is mainly mountain big sagebrush, antelope bitterbrush, green ephedra, and basin wildrye.

DISTRIBUTION AND EXTENT: Western Nevada and eastern California. These soils are not extensive with about 6,600 acres of the series mapped to date. MLRA 26.

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

SERIES ESTABLISHED: Mineral County Area, Nevada, 1985.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 28 cm (A1, A2, A3, and Bt1 horizons).
Argillic horizon - The zone from 20 to 48 cm (Bt1 and Bt2 horizons).
Vitrandic intergrade feature - The zone from the soil surface to 48 cm (A1, A2, A3, Bt1, and Bt2 horizons).
Paralithic contact - The zone from 48 to 76 cm (Cr layer).
Lithic contact - The boundary at 76 cm (R layer)
Particle-size control section and ashy-skeletal substitute class with glassy mineralogy - The zone from 20 to 48 cm (Bt1 and Bt2 horizons).

The revision of July 2004 updated the taxonomic class from Loamy-skeletal, mixed, superactive, frigid, shallow Aridic Argixerolls based on mineralogy data for adjacent soils.

ADDITIONAL DATA: Volcanic glass content determined locally by optical grain count with a polarizing petrographic microscope.
User Pedon ID: 2007NV021048.
Additional reviewers include: JFS-EWB-WED.

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National Cooperative Soil Survey
U.S.A.