LOCATION HANGROCK                NV

Established Series
Rev. SES-TM-JVC-JBF
12/2019

HANGROCK SERIES

The Hangrock series consists of shallow to a duripan, well drained soils that formed in alluvium derived from volcanic rocks and vitric pyroclastic materials. Hangrock soils are on fan remnants. Slopes are 2 to 15 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Ashy, glassy, mesic, shallow Haploxeralfic Argidurids

TYPICAL PEDON: Hangrock very gravelly ashy loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 40 percent gravel and 5 percent cobbles.

A--0 to 10 cm; light brownish gray (10YR 6/2) very gravelly ashy loam, dark brown (10YR 3/3) moist; moderate medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine interstitial pores; 5 percent cobbles and 35 percent gravel; neutral (pH 6.6); clear smooth boundary. (3 to 18 cm thick)

Bt1--10 to 23 cm; pale brown (10YR 6/3) gravelly ashy clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine tubular pores; common faint clay films on faces of peds; 15 percent gravel; neutral (pH 6.6); clear smooth boundary. (8 to 15 cm thick)

Bt2--23 to 43 cm; light yellowish brown (10YR 6/4) gravelly ashy clay loam, dark yellowish brown (10YR 4/4) moist; moderate fine prismatic structure parting to strong medium subangular blocky; hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine tubular pores; common distinct clay films on faces of peds; 15 percent gravel; neutral (pH 6.8) abrupt wavy boundary. (15 to 25 cm thick)

Bqm--43 to 61 cm; cemented material; very pale brown (10YR 8/2) yellowish brown (10YR 5/4) moist; massive; extremely hard, extremely firm, strongly cemented with fractured discontinuous lenses of very rigid material; 30 percent gravel; slightly alkaline (pH 7.4); gradual wavy boundary. (10 to 58 cm thick)

Bqkm--61 to 152 cm; cemented material; very pale brown (10YR 8/2) very pale brown (10YR 7/3) moist; strongly cemented; many strongly cemented plates with weakly cemented material between the plates; 30 percent gravel; secondary carbonate coats on some rock fragments and duripan fragments; strongly effervescent matrix; slightly alkaline (pH 7.6).

TYPE LOCATION: Washoe County, Nevada; about 1.5 miles southeast of the mouth of upper Hanging Rock Canyon; approximately 2,200 feet north and 450 feet east of the southwest corner of section 31, T. 42 N., R. 23 E.; USGS Nut Mountain 7.5 minute topographic quadrangle; latitude 41 degrees 30 minutes 35 seconds N and longitude 119 degrees 26 minutes 18 seconds W; WGS84 Decimal Degrees 41.5097222 latitude, -119.4383333 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry early June through October; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Depth to duripan: 36 to 50 cm.
Volcanic glass content: 35 to 60 percent in coarse silt through fine sand fractions.

Particle-size control section - Clay content: 25 to 35 percent.
Rock fragments: 15 to 35 percent, dominantly gravel. Lithology of fragments is volcanic rocks such as andesite, rhyolite, and tuff.

A horizon
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 3 or 4 moist; value is 6 dry after mixing the upper 18 cm.
Chroma: 2 or 3, dry or moist.

Bt horizons
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 3 through 5 moist.
Chroma: 2 through 6, dry or moist.
Texture: Gravelly ashy loam or gravelly ashy clay loam.
Clay content: 25 to 35 percent.
Rock fragments: 15 to 35 percent.
Structure: Subangular blocky and prismatic.

Bqm horizon
Rupture resistance: Moderately cemented or strongly cemented with discontinuous lenses that are very strongly cemented.
Cementation: Most fragments will fail at 1 joule; very strongly cemented pieces will typically fail at 3 joules.

COMPETING SERIES: There are currently no other soils in this family.

GEOGRAPHIC SETTING: Hangrock soils are on fan remnants. They formed in alluvium derived from volcanic rocks and vitric pyroclastic materials. Slopes are 2 to 15 percent. Elevations are 1,600 to 1,900 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 300 mm, the mean annual temperature is 7 to 10 degrees C, and the frost-free period is 80 to 110 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Saraph and Tuffo soils. Saraph and Tuffo soils have bedrock within 50 cm and do not have duripans.

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

USE AND VEGETATION: Hangrock soils are used for rangeland and wildlife habitat. The present vegetation is mainly Wyoming big sagebrush, bottlebrush squirreltail, and Thurber's needlegrass.

DISTRIBUTION AND EXTENT: Northwestern Nevada. These soils are moderately extensive. MLRA 23.

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

SERIES ESTABLISHED: Washoe County, Nevada (North Part), 1995. The name is coined from nearby Hanging Rock Canyon.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 10 cm (A horizon).
Argillic horizon - The zone from 10 to 43 cm (Bt1 and Bt2 horizons).
Duripan - The zone from 43 to 152 cm (Bqm and Bqkm horizons).
Particle-size control section and ashy substitute class with glassy mineralogy - The zone from 10 to 43 cm (Bt1 and Bt2 horizons).

ADDITIONAL DATA: Volcanic glass content determined locally by optical grain counts using a polarizing petrographic microscope.

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National Cooperative Soil Survey
U.S.A.