LOCATION HALVERT                 NV+CA

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

HALVERT SERIES

Halvert series consists of moderately deep, well drained soils that formed in colluvium and alluvium derived from basalt and andesite. Halvert soils are on plateaus. Slopes are 0 to 8 percent. The mean annual precipitation is about 280 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Very-fine, smectitic, mesic Vertic Durixerolls

TYPICAL PEDON: Halvert gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 5 cm; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; strong thin and medium platy structure; hard, very friable, moderately sticky and moderately plastic; many very fine roots; many very fine vesicular and interstitial pores; 5 percent cobbles and 15 percent gravel; slightly alkaline (pH 7.6); abrupt smooth boundary. (5 to 13 cm thick)

A2--5 to 13 cm; brown (7.5YR 5/2) gravelly clay loam, dark brown (7.5YR 3/2) moist; moderate medium and thick platy structure; hard, very friable, moderately sticky and moderately plastic; many very fine and common fine roots; many very fine tubularcommon very fine vesicular pores; 5 percent cobbles and 15 percent gravel; common thin pinkish gray (7.5YR 7/2) uncoated sand grains on horizontal faces of peds; slightly alkaline (pH 7.6); abrupt wavy boundary. (0 to 13 cm thick)

Btss--13 to 53 cm; brown (7.5YR 4/3) clay, dark brown (7.5YR 3/3) moist; moderate fine and medium prismatic structure parting to strong very fine and fine angular blocky; extremely hard, very firm, very sticky and very plastic; common very fine and few fine roots; few very fine tubular pores; many faint and distinct clay films on faces of peds and lining pores; vertical cracks 8 millimeters to 1 cm wide and 10 to 15 cm apart extend from a depth of 13 to 46 cm; few slickensides; few wedge-shaped aggregates tilted 30 degrees from horizontal; 10 percent gravel; slightly alkaline (pH 7.8); clear wavy boundary. (30 to 50 cm thick)

Btqk--53 to 69 cm; pink (7.5YR 7/4) gravelly clay, brown (7.5YR 5/4) moist; strong medium and coarse angular blocky structure; hard, friable, very sticky and very plastic; common very fine roots; common very fine tubular pores; many distinct clay films on faces of peds and lining pores; 5 percent cobbles and 15 percent gravel; 0.5 to 1.0 mm thick silica and carbonate coats on 50 percent of bottoms of rock fragments; few fine masses of secondary carbonate; moderately alkaline (pH 8.4); abrupt wavy boundary. (8 to 30 cm thick)

Bqkm--69 to 81 cm; reddish yellow (7.5YR 7/6) cemented material; reddish yellow (7.5YR 6/8) moist; strong thin and medium platy structure; extremely hard, extremely firm; continuous indurated laminar cap of 2 to 3 mm thick silica laminae; horizontal root mat at upper boundary with many very fine and fine, few medium roots; violently effervescent in few places; clear smooth boundary. (10 to 30 cm thick)

Cr--81 to 107 cm; fractured and weathered basalt rock; illuvial clay and silica lining fractures.

TYPE LOCATION: Washoe County, Nevada; on the Barrel Springs Road at the Nevada-California state line; approximately 1,700 feet north and 450 feet east of the southwest corner of section 20, T. 46 N., R. 18 E.; USGS Barrel Springs 7.5 minute topographic quadrangle; latitude 41 degrees 53 minutes 30 seconds N and longitude 119 degrees 59 minutes 52 seconds W; WGS84 Decimal Degrees 41.8916667 latitude, -119.9977778 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Moist in winter and spring; dry from July through October; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Mollic epipedon thickness:30 to 60 cm; includes the Btss horizon.
Depth to duripan: 50 to 80 cm.
Depth to bedrock: 60 to 100 cm to a paralithic contact. The paralithic materials below the contact are weathered basalt or andesite.
Other features: There is an abrupt clay increase of 25 to 35 percent within a vertical distance of 3 cm between the A and Btss horizons.

Particle-size control section - Clay content: 60 to 70 percent.
Rock fragments: 10 to 25 percent, mainly gravel. Lithology of fragments is volcanic rocks such as basalt or andesite.

A horizons
Value: 5 or 6 dry, 2 or 3 moist; dry value of 6 is only in the upper 5 cm.
Chroma: 2 or 3, dry or moist.
Reaction: Neutral or slightly alkaline.
Organic matter content: 1 or 2 percent.

Btss horizon
Hue: 10YR or 7.5YR.
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 3 or 4 dry.

Texture: Clay or gravelly clay.
Consistence: Hard through extremely hard dry, friable to very firm moist.
Reaction: Slightly alkaline or moderately alkaline.
Organic matter content: 1 or 2 percent.
Vertic features: Vertical cracks 5 to 25 mm wide, few to common slickensides and wedge-shaped aggregates.

Btqk horizon
Hue: 10YR or 7.5YR.
Value: 5 through 7 dry, 4 through 6 moist.
Chroma: 3 or 4, dry or moist.
Clay content: 55 to 65 percent.
Texture: Clay or gravelly clay.
Rock fragments: 10 to 25 percent.
Reaction: Slightly alkaline or moderately alkaline.
Effervescence: Noneffervescent or slightly effervescent.
Identifiable secondary carbonates: Few fine or medium masses.
Other features: Secondary coats of silica and carbonate are on undersides of rock fragments.

Bqkm horizon
Cementation: Continuous 2 to 3 mm indurated silica laminae capped duripan.

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

GEOGRAPHIC SETTING: Halvert soils are on plateaus. They typically occur on footslope positions. They formed in colluvium and alluvium derived from basalt or andesite. Slopes are 0 to 8 percent. Elevations range from 1,525 to 1,880 meters. The mean annual precipitation is 250 to 300 mm, the mean annual temperature is 7 to 8 degrees C, and the frost-free period is 80 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Devada, Jaybee and Tunnison soils. Devada and Jaybee soils are shallow to bedrock. Tunnison soils have vertical cracks that extend to the surface and do not have a duripan.

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

USE AND VEGETATION: Halvert soils are used for livestock grazing and wildlife habitat. The present vegetation is dominantly Lahontan sagebrush, Sandberg's bluegrass, bluebunch wheatgrass, and bottlebrush squirreltail.

DISTRIBUTION AND EXTENT: Northwestern Nevada and northeastern California. These soils are not extensive with about 4,500 acres of the series mapped to date. MLRA 23.

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

SERIES ESTABLISHED: Washoe County, Nevada (North Part), 1995. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 53 cm (A1, A2 and Btss horizons).
Argillic horizon - The zone from 13 to 69 cm (Btss and Btqk horizons).
Slickensides and other vertic features - The zone from 13 to 53 cm (Btss horizon).
Identifiable secondary carbonates - The zone from 53 to 69 cm (Btqk horizon).
Duripan - The zone from 69 to 81 cm (Bqkm horizon).
Paralithic contact - The boundary at 81 cm to underlying weathered bedrock (Cr layer).
Particle-size control section - The zone from 13 to 63 cm (Btss and part of the Btqk horizons).

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National Cooperative Soil Survey
U.S.A.