LOCATION BIGWASH                 NV

Established Series
Rev. CWL/TM/JVC/JBF
01/2012

BIGWASH SERIES

The Bigwash series consists of very deep, well drained soils that formed in alluvium derived from limestone and minor amounts of quartzite. Bigwash soils are on drainageways. Slopes are 0 to 8 percent. The mean annual precipitation is about 450 mm and the mean annual temperature is about 5 degrees C.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Cumulic Haploxerolls

TYPICAL PEDON: Bigwash loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with approximately 5 percent gravel.

A1--0 to 8 cm; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure parting to weak fine subangular blocky; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots; common very fine and fine, and few medium tubular and interstitial pores; 5 percent gravel; strongly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (6 to 20 cm thick)

A2--8 to 24 cm; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; moderate coarse subangular blocky structure parting to weak medium subangular blocky; soft, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; common very fine and fine, and few medium tubular and interstitial pores; 5 percent gravel; strongly effervescent; strongly alkaline (pH 8.5); clear smooth boundary. (10 to 25 cm thick)

AB1--24 to 40 cm; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; moderate coarse subangular blocky structure parting to moderate medium subangular blocky; soft, very friable, slightly sticky and slightly plastic; common very fine, and few fine roots; common very fine and fine, and few medium tubular and interstitial pores; 5 percent gravel; violently effervescent; moderately alkaline (pH 8.1); clear smooth boundary. (10 to 30 cm thick)

AB2--40 to 77 cm; brown (10YR 4/3) loam, very dark brown (10YR 2/2) moist; moderate coarse subangular blocky structure parting to moderate medium subangular blocky; soft, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine, and few fine and medium tubular and interstitial pores; 10 percent gravel; strongly alkaline (pH 8.7). (30 to 50 cm thick)

AB3--77 to 152 cm; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; moderate coarse subangular blocky structure parting to moderate medium subangular blocky; soft, very friable, slightly sticky and slightly plastic; few very fine and fine roots; few very fine, fine, and medium tubular and interstitial pores; 10 percent gravel; strongly alkaline (pH 8.7).

TYPE LOCATION: White Pine County, Nevada; in the Snake Range; about 1.5 miles south of Cedar Cabin Spring in Big Springs Wash and about 100 feet east of jeep trail; USGS Arch Canyon 7.5 minute topographic quadrangle; latitude 38 degrees 46 minutes 28.0 seconds N and longitude 114 degrees 14 minutes 8.0 seconds W; UTM zone 11, 0740163e, 4295377n, NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter, spring, and early summer, dry in all parts at least 45 consecutive days following the summer solstice (July and August), but intermittently moist in the upper part for 10 to 20 days cumulative due to convection storms between July and September; This soil receives additional run-on moisture; xeric soil moisture regime.
Mean annual soil temperature: 6 to 7 degrees C.
Mollic epipedon thickness: 100 to 150 cm, with irregular organic carbon distribution.

Particle-size control section - Clay content: Averages 12 to 18 percent;
Rock fragments: 5 to 15 percent, mainly gravel. Lithology of the fragments is mainly limestone.

A horizons
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Organic matter content: 2 to 4 percent.
Reaction: Slightly alkaline to strongly alkaline.

AB horizons
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Loam or sandy loam.
Clay content: 12 to 18 percent.
Rock fragments: 5 to 15 percent, mainly as gravel.
Structure: Weak to moderate, medium or coarse subangular blocky.
Consistence: Soft or slightly hard, dry.
Reaction: Moderately alkaline or strongly alkaline.
Calcium carbonate equivalent: 0 to 5 percent.
Other features: Some pedons contain thin subhorizons with 35 to 45 percent rock fragments but when averaged it is less than 15 percent. Some pedons have ABk subhorizons with common (1 to 15 percent) secondary calcium carbonate concretions on the bottom of rock fragments.

COMPETING SERIES: These are the Freels, Mooretown, Rubicity, and Toefoot series.

Freels and Mooretown soils have redoximorphic features and endosaturation within 150 cm of the soil surface. Rubicity soils have a profile reaction of slightly acid or neutral and contain 15 to 35 percent gravel. Toefoot soils have a mollic epipedon that is 50 to 79 cm thick and have secondary calcium carbonate at 18 to 28 cm.

GEOGRAPHIC SETTING: Bigwash soils are on drainageways in mountains. These soils formed in alluvium derived from limestone and minor amounts of quartzite. Slopes are 0 to 8 percent. Elevations range from 1,890 to 2,800 meters. The climate is dry-subhumid, cool, moist winters and warm, dry summers. The mean annual precipitation is 400 to 500 mm. These soils receive additional run-on moisture making it wetter than the precipitation zone would indicate. The mean annual temperature is 4 to 6 degrees C, and the frost-free period is 40 to 70 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cedarcabin and Noski soils. Cedarcabin soils are moderately deep and contain 35 to 65 percent rock fragments. Noski soils have are shallow and have calcic horizons.

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

USE AND VEGETATION: Bigwash soils are used for recreation, livestock grazing, and wildlife habitat. The potential native vegetation is mainly basin wildrye and basin big sagebrush. This pedon is correlated to Ecological Site R028AY090NV, Loamy Bottom 10-14 P.Z.

DISTRIBUTION AND EXTENT: Eastern Nevada. These soils are not extensive. MLRA 28A.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.

SERIES ESTABLISHED: White Pine County, Great Basin National Park, Nevada, 2009. The name is coined from a local drainageway.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 152 cm (A1, A2, AB1, AB2, and AB3 horizons).
Particle-size control section - The zone from 25 to 100 cm (AB2 horizon and parts of the AB1 and AB3 horizons).

ADDITIONAL DATA: User Pedon ID: 06NV778026-CWL

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National Cooperative Soil Survey
U.S.A.