LOCATION WASSIT NV

Established Series
Rev. EWB-CMH-WED-JVC
06/2017

WASSIT SERIES

The Wassit series consists of very shallow and shallow, well drained soils that formed in residuum and colluvium derived from volcanic rocks and influenced by eolian volcanic ash. Wassit soils are on hills and mountains. Slopes are 15 to 75 percent. The mean annual precipitation is about 300 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Lithic Xeric Haplargids

TYPICAL PEDON: Wassit very gravelly ashy very fine sandy loam--forestland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 3 cm; pale brown (10YR 6/3) very gravelly ashy very fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate medium and thick platy structure parting to weak thin platy; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine interstitial pores and few very fine vesicular pores; 40 percent gravel; neutral (pH 7.0); clear smooth boundary. (3 to 8 cm thick)

A2--3 to 15 cm; pale brown (10YR 6/3) very gravelly ashy sandy loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine roots; common very fine tubular and few very fine interstitial pores; 45 percent gravel; neutral (pH 7.2); clear smooth boundary. (3 to 18 cm thick)

Bt1--15 to 23 cm; pale brown (10YR 6/3) very gravelly ashy loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common coarse and medium, few fine and very fine roots; common very fine tubular pores and few very fine interstitial pores; 45 percent gravel; few faint clay bridges between sand grains; neutral (pH 7.2); clear wavy boundary. (3 to 13 cm thick)

Bt2--23 to 30 cm; light olive brown (2.5Y 5/4) very gravelly ashy clay loam, olive brown (2.5Y 4/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common coarse and medium, few fine and very fine roots; common very fine tubular pores and few very fine interstitial pores; 50 percent gravel; common faint and few distinct clay films on faces of peds; neutral (pH 7.2); clear irregular boundary. (8 to 13 cm thick)

R--30 cm; hard, fractured, altered volcanic rock; some fine-earth material in fractures.

TYPE LOCATION: Mineral County, Nevada; in the Wassuk Range about 19.5 miles northwest of Hawthorne; approximately 700 feet east and 100 feet north of the southwest corner of section 2, T. 10 N., R. 28 E.; USGS Reese River Canyon 7.5 minute topographic quadrangle; 38 degrees 45 minutes 02 seconds north latitude and 118 degrees 50 minutes 0 seconds west longitude; WGS84 Decimal Degrees 38.7506667 latitude, -118.8333333 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring; dry in summer and fall except for 10 to 20 days cumulative in some part between July and October due to convection storms; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 5 to 8 degrees C.
Ochric epipedon thickness: 5 to 25 cm; the presence of light colored volcanic ash results in a value of 6 dry, otherwise the epipedon would fit mollic criteria.
Depth to bedrock: 15 to 35 cm to a lithic contact.
Reaction: Neutral or slightly alkaline.

Particle-size control section - Clay content: 18 to 27 percent.
Rock fragments: 35 to 60 percent, mainly gravel. Lithology of fragments is volcanic rocks such as andesite.

A horizons
Chroma: 2 or 3, dry or moist.
Clay content: 10 to 18 percent.
Organic matter content: 1 to 3 percent.
Volcanic glass content: 15 to 30 percent in coarse silt through fine sand fractions.

Bt horizons
Hue: 10YR or 2.5Y.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Very gravelly ashy loam or very gravelly ashy clay loam.
Clay content: 25 to 35 percent; subhorizons may have up to 40 percent clay.
Organic matter content: 1 to 3 percent.
Volcanic glass content: 15 to 30 percent in coarse silt through fine sand fractions.

COMPETING SERIES: These are the Bayhorse and Bregar series.

Bayhorse soils do not have significant amounts of volcanic glass. Bregar soils are not intermittently moist in some part following summer convection storms.

GEOGRAPHIC SETTING: Wassit soils are on hills and mountains. These soils formed in residuum and colluvium derived from volcanic rocks and influenced by eolian volcanic ash. The probable sources of the volcanic ash are the Mono Craters and Long Valley Caldera in eastern California. Slopes are 15 to 75 percent. Elevations range from 1,640 to 2,740 meters. The mean annual precipitation is 250 to 350 mm, the mean annual temperature is 4 to 7 degrees C, and the frost-free period is 80 to 110 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lazan and Nupart soils. These soils are sandy-skeletal and do not have argillic horizons.

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

USE AND VEGETATION: Wassit soils are used for forestland and wildlife habitat. The vegetation is a forest canopy of singleleaf pinyon and Utah juniper with an understory of mountain big sagebrush and pine bluegrass.

DISTRIBUTION AND EXTENT: Western Nevada. These soils are moderately extensive. MLRA 26.

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

SERIES ESTABLISHED: Mineral County Area, Nevada, 1985.

REMARKS: The revision of October 2002 updates the taxonomic class, from Loamy-skeletal, mixed, frigid Lithic Mollic Haploxeralfs, because of a change in concept for moisture regime.

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 15 cm (A1 and A2 horizons).
Argillic horizon - The zone from 15 to 30 cm (Bt1 and Bt2 horizons).
Vitrandic intergrade properties - The zone from the soil surface to 30 cm (A1, A2, Bt1, and Bt2 horizons).
Lithic contact - The boundary at 30 cm to underlying hard, unweathered bedrock (R layer).
Particle-size control section - The zone from the soil surface to 30 cm (A1, A2, Bt1, and Bt2 horizons).

ADDITIONAL DATA: A pedon similar to Wassit, but higher in volcanic glass, has full characterization by the Soil Survey Laboratory (SSL), Lincoln, NE, as soil survey sample number S82NV-021-008 (pedon # 82P0629).

User Pedon ID: 2007NV0211156.

National Cooperative Soil Survey
U.S.A.