LOCATION ZONO CA

Established Series
Rev. DV-ET-MAV-JVC-ET
12/2019

ZONO SERIES

The Zono series consists of deep, somewhat excessively drained soils that formed in rhyolitic volcanic ash over residuum weathered from granitic, dacitic, or basaltic rock. Zono soils are on hills and mountains. Slopes are 15 to 50 percent. The mean annual precipitation is about 300 mm inches and the mean annual temperature is about 7.2 degrees C.

TAXONOMIC CLASS: Ashy over loamy, glassy over mixed, superactive, nonacid, mesic Vitrandic Torriorthents

TYPICAL PEDON: Zono ashy coarse sand--on a 38 percent southwest-facing slope at 2,310 meters elevation under big sagebrush and rabbitbrush vegetation. (Colors are for dry soil unless otherwise noted. When described on October 19, 1977 the soil was dry throughout.)

A1--0 to 8 cm; light brownish gray (10YR 6/2) ashy coarse sand, dark grayish brown (10YR 4/2) moist; single grain; loose, nonsticky and nonplastic; few very fine roots; many very fine interstitial pores; 10 percent pumice paragravel; slightly acid (pH 6.5); abrupt smooth boundary. (5 to 10 cm thick)

A2--8 to 61 cm; light gray (10YR 7/2) ashy loamy sand, grayish brown (10YR 5/2) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and few fine through coarse roots; many very fine interstitial pores; 10 percent pumice paragravel; slightly acid (pH 6.5); gradual wavy boundary. (25 to 71 cm thick)

2C--61 to 76 cm; light brownish gray (10YR 6/2) gravelly ashy sand, dark grayish brown (10YR 4/2) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and few fine roots; many very fine interstitial pores; 15 percent gravel, 5 percent cobbles, and 1 percent stones; slightly acid (pH 6.5); abrupt wavy boundary. (10 to 20 cm thick)

3Ab1--76 to 86 cm; pale brown (10YR 6/3) very cobbly sand, brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common very fine and few fine roots; many very fine interstitial pores; 15 percent gravel, 25 percent cobbles, and 10 percent stones; neutral (pH 7.0); abrupt wavy boundary. (10 to 25 cm thick)

3Ab2--86 to 104 cm; light yellowish brown (10YR 6/4) gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; massive; hard, friable, slightly sticky and nonplastic; few very fine and fine roots; many very fine interstitial pores; 15 percent gravel, 5 percent cobbles, and 1 percent stones; neutral (pH 7.0); gradual wavy boundary. (15 to 25 cm thick)

3Cr--104 cm; weathered granitic bedrock.

TYPE LOCATION: Mono County, California; about 13 miles east of Lee Vining near Cowtrack Mountain and 150 feet north-northeast of dirt road; 1,800 feet north and 2,600 feet east of the projected southwest corner of section 15, T. 1 N., R. 28 E.; USGS Cowtrack Mountain 7.5 minute topographic quadrangle; latitude 37 degrees 56 minutes 36 seconds N and longitude 118 degrees 52 minutes 35 seconds W; WGS84 Decimal Degrees 37.9433333 latitude, -118.8763889 longitude.
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RANGE IN CHARACTERISTICS:

Soil moisture - The soil between depths of 25 to 100 cm is usually dry from about May 30 to November 15, and is moist in some or all parts the rest of the time; aridic moisture regime that borders on xeric.

Mean annual soil temperature - 8.3 to 11.1 degrees C.; the soil temperature is about 5 degrees C. from about April 1 to December 20, and above 8.3 degrees C. from about April 15 to November 30.

Ashy mantle thickness and depth to buried horizons - 24 to 36 inches in most pedons.

Depth to bedrock - 100 to 152 cm to a paralithic or lithic contact.

Particle-size control section - Clay content: 1 to 6 percent; Rock fragments: Averages 10 to 20 percent in the upper part and 25 to 60 percent in the contrasting lower part. Lithology of fragments in the contrasting lower part are granitic rocks such as granodiorite or volcanic rocks such as dacite and basalt.

Reaction - Slightly acid or neutral.

A horizons
Dry color: 10YR 6/2, 7/1, 7/2; or 2.5Y 6/2.
Moist color: 10YR 4/2, 5/1, 5/2; or 2.5Y 4/2.
Texture: Ashy loamy sand or ashy coarse sand.
Pararock fragments: 5 to 15 percent pumice paragravel 2 to 10 mm in diameter. Organic carbon content: 0.2 to 0.4 percent.
Volcanic glass content: 60 to 100 percent in coarse silt through very coarse sand fractions.
Bulk density: 1.1 to 1.25 g/cc dry and 1.3 to 1.45 g/cc moist.

2C horizon
Dry color: 10YR 6/2, 6/3, 6/4, or 7/2.
Moist color: 10YR 4/2, 4/3, 4/4, or 5/2.
Texture: Ashy loamy sand or gravelly ashy sand.
Rock fragments: Total range is 15 to 30 percent; 10 to 20 percent gravel; 5 to 10 percent cobbles and stones.
Volcanic glass content: 60 to 100 percent in coarse silt through very coarse sand fractions.
Bulk density: 1.1 to 1.25 g/cc dry and 1.3 to 1.45 g/cc moist.

3Ab horizons
Dry color: 10YR 6/2, 6/3, 6/4, or 7/2.
Moist color: 10YR 4/2, 4/3, 4/4, or 5/2.
Texture: Stratified very cobbly sand to gravelly sandy loam.
Rock fragments: 25 to 60 percent.
Other features: Buried B horizons are present below the control section in some pedons.

COMPETING SERIES: At present, there are no other series in this family.

GEOGRAPHIC SETTING: Zono soils are on hills and mountains. They typically occur on backslope positions. These soils formed in rhyolitic volcanic ash over residuum weathered from granitic, dacitic, or basaltic rock. The source of the airfall (eolian) volcanic ash are the adjacent Mono Craters. Slopes are 15 to 50 percent. Elevations range from 2,075 to 2,445 meters. The mean annual precipitation is 250 to 300 mm. The mean annual temperature is 5.6 to 7.8 degrees C. Mean January temperature is about -1 degrees C. and mean July temperature is about 19.4 degrees C. The frost-free period is 100 to 125 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brantel and Cowtrack soils. Brantel soils are very deep, do not have strongly contrasting loamy material within a depth of 100 cm, and are on alluvial fans, fan remnants, and hills. Cowtrack soils have a frigid soil temperature regime and occur at higher elevations.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively drained; low surface runoff; rapid permeability.

USE AND VEGETATION: Zono soils are used for livestock grazing and wildlife habitat. The vegetation consists of mountain big sagebrush, antelope bitterbrush, Indian ricegrass, needleandthread, and western needlegrass.

DISTRIBUTION AND EXTENT: East-central California. These soils are moderately extensive. MLRA 26.

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

SERIES ESTABLISHED: Mono County (Benton-Owens Valley Soil Survey), California, 1996.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - The zone from the soil surface to 18 cm(A1 and part of the A2 horizons).
Vitrandic intergrade properties - The zone from the soil surface to 76 cm (A1, A2, and 2C horizons).
Buried horizons - The zone from 30 to 41 inches (3Ab1 and 3Ab2 horizons).
Major lithologic discontinuity - The abrupt change to strongly ontrasting material at 76 cm (3Ab1 and 3Ab2 horizons).

Paralithic contact - The boundary at 104 cm inches to underlying weathered bedrock (3Cr layer).

Particle-size control section - The zone from 25 to 100 cm (2C and 3Ab1 horizons and parts of the A2 and 3Ab2 horizons).

ADDITIONAL DATA: The mean annual soil temperature of 8.3 to 11.1 degrees C. is extrapolated from actual temperature transect data using Rod Arkley's equation.

National Cooperative Soil Survey
U.S.A.