LOCATION COOPERWASH              NV

Established Series
Rev. CWL/PWB/TM
11/2016

COOPERWASH SERIES

The Cooperwash series consists of very deep, well drained soils that formed in residuum and colluvium derived from quartzite and some limestone. Cooperwash soils are on mountains. Slopes are 4 to 50 percent. The mean annual precipitation is about 575 mm and the mean annual temperature is about 5 degrees C.

TAXONOMIC CLASS: Fine, smectitic Vertic Argicryolls

TYPICAL PEDON: Cooperwash clay loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with approximately 20 percent gravel.

A--0 to 6 cm; dark grayish brown (10YR 4/2) clay loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure parting to strong medium granular; slightly hard, friable, slightly sticky and slightly plastic; few very fine and common fine roots; common very fine and fine, and few medium interstitial and tubular pores; neutral (pH 7.2); clear smooth boundary. (4 to 10 cm thick)

Bt1--6 to 25 cm; dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; strong coarse subangular blocky structure parting to strong fine subangular blocky; hard, firm, moderately sticky and very plastic; many very fine, common fine, and few medium roots; common very fine and fine and few medium interstitial and tubular pores; common distinct clay films on faces of peds; neutral (pH 7.3); clear smooth boundary.

Bt2--25 to 46 cm; brown (10YR 5/3) clay, dark brown (10YR 3/3) moist; strong coarse prismatic structure parting to strong medium angular blocky; very hard, very firm, moderately sticky and very plastic; common very fine, and few fine and medium roots; common very fine and fine tubular pores; common distinct clay films on faces of peds and lining pores; 2 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (combined thickness of the Bt horizons 30 to 50 cm)

Btkss1--46 to 81 cm; brown (10YR 5/3) clay, dark brown (10YR 3/3) moist; strong coarse prismatic structure parting to moderate medium angular blocky; very hard, very firm, moderately sticky and very plastic; few very fine and fine roots; common very fine and fine tubular pores; many distinct clay films on faces of peds and lining pores and few (15 percent) slickensides; finely disseminated secondary calcium carbonate, common (5 percent) medium irregular secondary calcium carbonate masses; few fine strong brown (7.5YR 5/6) iron and manganese concentrations; 2 percent gravel; slightly alkaline (pH 7.7); gradual smooth boundary. (30 to 50 cm thick)

Btkss2--81 to 152 cm; brown (10YR 5/3) clay, brown (10YR 4/3) moist; strong coarse prismatic structure parting to moderate medium angular blocky; very hard, very firm, moderately sticky and very plastic; few very fine and fine roots; common very fine and fine tubular pores; many prominent clay films on faces of peds and lining pores and few (20 percent) slickensides; few (2 percent) 5 mm wide cracks; finely disseminated secondary calcium carbonate and common (8 percent) medium irregular secondary calcium carbonate masses; slightly alkaline (pH 7.8).

TYPE LOCATION: White Pine County, Nevada; about 3 miles east of Cave Lake and 50 feet south of the Cave Mountain road; about 1,250 feet south and 150 feet west of the northeast corner sec. 11, T. 15 N., R. 65 E.; USGS Cave Creek 7.5 minute topographic quadrangle; latitude 39 degrees 11 minutes 2.0 seconds N and longitude 114 degrees 38 minutes 5.0 seconds W; WGS84 Decimal Degrees 39.183889 latitude, -114.634722 longitude.

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); Xeric soil moisture regime.
Mean annual soil temperature: 4 to 7 degrees C.
Mollic epipedon thickness: 80 to 150 cm; includes the Bt horizons and also the Btkss1 horizon in some pedons.
Argillic horizon thickness: 146 to 150 cm.
Depth to secondary calcium carbonate: 34 to 60 cm.
Vertic properties: Cracks 5 mm or more wide below 50 cm occur during dry periods in horizons having slickensides.
Linear extensibility (LE): 6 to 9 cm.

Particle-size control section - Clay content; Averages 40 to 60 percent.
Rock fragment content; Averages 0 to 5 percent, mainly as gravel.


A horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Organic matter content: 1 to 3 percent.

Bt horizons
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Clay content: 35 to 60 percent.
Rock fragments: 0 to 5 percent, mainly as gravel.
Reaction: Neutral or slightly alkaline.

Btkss horizons
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Clay content: 40 to 60 percent.
Rock fragments: 0 to 5 percent, mainly as gravel.
Effervescence: Strongly effervescent or violently effervescent.
Reaction: Slightly alkaline or moderately alkaline.

COMPETING SERIES: These are the Beaverdam, Buckskin, Cimarron, Cucharas, Gillum, Gourley, Hairpin, Heathcoat, Helmet, Savar, Slights, Sudduth, Sudpeak, Toponce, Warridge, Wetopa, and Youman series.

Beaverdam soils have O horizons, udic soil moisture regimes, and mollic epipedons that are 25 to 40 cm thick.
Buckskin soils are noncalcareous to 150 cm or deeper and the mollic epipedon ranges from 25 to 40 cm thick.
Cimarron soils have mollic epipedons less than 40 cm thick and an ustic soil moisture regime.
Cucharas soils have paralithic contacts at 50 to 100 cm.
Gillum soils have AE and E/Bt horizons and mollic epipedons that are 18 to 40 cm thick.
Gourley soils have mollic epipedons that are 18 to 38 cm thick.
Hairpin soils have Bt/E horizons that are 15 to 36 cm thick and mollic epipedons that are 25 to 38 cm thick.
Heathcoat soils have mollic epipedons that are 18 to 38 cm thick and a calcic horizon at 25 to 76 cm.
Helmet soils have an udic moisture regime and a mollic epipedon less than 40 cm thick.
Savar soils are slightly alkaline or moderately alkaline in the A horizon.
Slights soils have a mollic epipedon that is 40 to 64 cm thick.
Sudduth soils have a 2B/E horizon, and an udic soil moisture regime.
Sudpeak soils have a water table at 91 to 183 cm.
Toponce soils have an udic moisture regime and a mollic epipedon that is 46 to 64 cm thick.
Warridge soils do not have an OSD available.
Wetopa soils have moderately acid to neutral soil reaction and do not contain carbonates.
Youman soils have hue of 5YR to 10R throughout the subsoil and substratum.

GEOGRAPHIC SETTING: Cooperwash soils are on mountains. They typically occur on shoulder and backslope positions. These soils formed in colluvium and residuum derived from quartzite and some limestone. Slopes are 4 to 50 percent. Elevations are 2,500 to 2,950 meters. The climate is moist-subhumid with cold, wet winters and cool, dry summers. The mean annual precipitation is 450 to 700 mm, the mean annual temperature is 3 to 6 degrees C., and the frost-free period is 40 to 60 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brokit, Kolcheck, and Successloop series.

Brokit soils have a strongly contrasting particle-size control section with 12 to 20 percent clay in the upper part and 3 to 10 percent clay in the lower part. Kolcheck soils are somewhat poorly drained and have 2 to 20 percent rock fragments in the particle-size control section. Successloop soils have 27 to 35 percent clay and 35 to 50 percent rock fragments in the particle-size control section.

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

USE AND VEGETATION: Cooperwash soils are used for livestock grazing and wildlife habitat. The potential native vegetation is mainly low sagebrush and bluebunch wheatgrass. This site is correlated to Ecological Site R28BY036NV, Claypan 14+ P.Z.

DISTRIBUTION AND EXTENT: East-central Nevada. These soils are not extensive. MLRA 28B.

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

SERIES ESTABLISHED: White Pine County, Humboldt-Toiyabe National Forest, South Part, Nevada, 2013. The name is coined from a local drainage way.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 81 cm (A, Bt1, Bt2, and Btkss1 horizons).
Argillic horizon - The zone from 6 to 152 cm (Bt1, Bt2, Btkss1, and Btkss2 horizons).
[JC1]
Slickensides and identifiable secondary carbonates - The zone from 46 to 152 cm (Btkss1 and Btkss2 horizons).
Particle-size control section - The zone from 6 to 56 cm (Bt1 and Bt2 horizons and the upper part of the Btkss1 horizon).

ADDITIONAL DATA: User Pedon ID 07NV778006-CWL

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National Cooperative Soil Survey
U.S.A.