LOCATION ZAQUA                   NV

Established Series
Rev. RWW/DJM/RLB/JBF
07/2016

ZAQUA SERIES

The Zaqua series consists of shallow, well drained soils that formed in residuum and colluvium derived from volcanic tuffs. Zaqua soils are on mountains and hills. Slopes are 15 to 50 percent. The mean annual precipitation is about 200 mm and the mean annual temperature is about 12 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic, shallow Ustic Haplargids

TYPICAL PEDON: Zaqua very gravelly sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.) The surface is partially covered with 15 percent cobbles and 35 percent gravel.

A--0 to 8 cm; grayish brown (10YR 5/2) very gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; moderate thin platy structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine and fine vesicular pores; 5 percent cobbles and 35 percent gravel ; slightly alkaline (pH 7.6); clear smooth boundary. (8 to 13 cm thick)

Bt1--8 to 23 cm; brown (7.5YR 5/4) very gravelly clay loam, brown (7.5YR 4/4) moist; moderate fine angular blocky structure; hard, friable, very sticky and very plastic; common very fine and fine roots commonly occurring as exped; common very fine and fine tubular pores; many distinct clay films lining pores and common pressure faces on peds; 8 percent cobbles and 35 percent gravel; neutral (pH 7.0); clear smooth boundary. (15 to 23 cm thick)

Bt2--23 to 43 cm; brown (7.5YR 5/4) very gravelly sandy clay loam, brown (7.5YR 4/4) moist; moderate fine and medium angular blocky structure; hard, friable, moderately sticky and very plastic; common very fine and fine roots commonly occurring as expend; common very fine tubular pores; common distinct clay films lining pores and common pressure faces on peds; 12 percent cobbles and 35 percent gravel; neutral (pH 7.0); abrupt wavy boundary. (15 to 28 cm thick)

Cr--43 cm; weathered rhyolitic tuffs.

TYPE LOCATION: Lincoln County Nevada, approximately 1.5 miles southeast of Samscamp Spring about 750 feet north and 2000 feet west of the projected southeast corner of section 36, T. 7 S., R. 69 E.; USGS Jacks Mountain 7.5 minute topographic quadrangle; latitude 37 degrees 17 minutes 29 seconds N, and longitude 114 degrees 13 minutes 19 seconds W; WGS84 Decimal Degrees 37.2913889 latitude, -114.2219444 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in late summer and for short periods in winter and spring; aridic soil moisture regime bordering on ustic.
Mean annual soil temperature: 12 to 14 degrees C.
Depth to the paralithic contact; 36 to 50 cm.
Reaction: Neutral or slightly alkaline.
Carbonates: Noneffervescent or slightly effervescent.

Particle-size control Section - Clay content: 27 to 35 percent.
Rock fragments: 35 to 60 percent mainly gravel.

A horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3.

Bt horizons
Hue: 7.5YR or 5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4.
Texture: Very gravelly sand clay loam or very gravelly clay loam.
Other features: Few very thin carbonate coats on the undersides of rock fragments occur in some pedons.

COMPETING SERIES: These are the Cetrepas, Lastone and McClanahan series.

Cetrepas and Lastone soils have less than 27 percent clay in the particle-size control section. McClanahan soils have a paralithic contact within 36 cm.

GEOGRAPHIC SETTING: Zaqua soils are on crest and side slopes of low mountains and hills. These soils formed in residuum and colluvium derived from volcanic tuffs. Slopes are 15 to 50 percent. Elevations are 1,070 to 1,525 meters. The climate is semiarid with cool, moist winters and hot, intermittently moist summers. The mean annual precipitation is 200 to 250 mm. The mean annual temperature is 11 to 13 degrees C and the frost-free season is 160 to 190 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kanesprings, Rochpah, Winklo and Wyva soils. Kanesprings soils have a duripan over bedrock and have a thermic temperature regime. Rochpah soil lack an argillic horizon and have a calcic horizon. Winklo soils have a fine textured particle-size control section and are deeper than 50 cm to a paralithic contact. Wyva soils have a lithic contact within 50 cm of the soil surface and are cooler than 12 degrees C.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium to rapid runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly blackbrush, desert bitterbrush, green ephedra, juniper, banana yucca and galleta.

DISTRIBUTION AND EXTENT: Southern Nevada. Zaqua soils are not extensive. MLRA 29.

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

SERIES ESTABLISHED: Lincoln County, Nevada, South Part, 1992.

REMARKS: Diagnostic horizons and features recognized in the pedon are:
Ochric epipedon - The zone from the soil surface to 8 cm (A horizon).
Argillic horizon - The zone from 8 to 43 cm (Bt2 horizons).
Paralithic contact - The boundary at 43 cm (2Cr layer).
Particle-size control section - The zone from 8 to 43 cm (Bt1 and Bt2 horizons).

ADDITIONAL DATA: NSSL number S86NV-017-010.

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National Cooperative Soil Survey
U.S.A.