LOCATION CHARWELL                NV

Established Series
Rev. MTS/TM/RLB/JBF
01/2019

CHARWELL SERIES

The Charwell series consists of moderately deep, well drained soils that formed in residuum derived from volcanic rocks with minor amounts of loess and volcanic ash. Charwell soils are on plateaus and hills. Slopes are 0 to 30 percent. The mean annual precipitation is about 360 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Very-fine, smectitic, frigid Abruptic Argiduridic Durixerolls

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

A1--0 to 8 cm; grayish brown (10YR 5/2) gravelly loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and slightly plastic; many very fine, common fine and medium roots; many very fine, common fine and medium tubular pores; 20 percent gravel and 10 percent cobbles; neutral (pH 6.8); abrupt smooth boundary. (5 to 15 cm thick)

A2--8 to 20 cm; grayish brown (10YR 5/2) very gravelly clay loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine, few medium roots; common very fine tubular, common very fine and fine, few medium interstitial pores; 35 percent gravel and 20 percent cobbles; neutral (pH 6.8); abrupt wavy boundary. (0 to 15 cm thick)

Bt1--20 to 25 cm; grayish brown (10YR 5/2) gravelly clay, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; hard, firm, very sticky and very plastic; common very fine, few fine and medium roots; common very fine, few fine and medium tubular pores; common distinct films on faces of peds and lining pores; 25 percent gravel and 5 percent cobbles; neutral (pH 6.6); abrupt wavy boundary. (0 to 8 cm thick)

Bt2--25 to 46 cm; yellowish brown (10YR 5/4) gravelly clay, dark yellowish brown (10YR 4/4) moist on interiors of peds, dark yellowish brown (10YR 3/4) moist on faces of peds; strong medium prismatic structure parting to strong medium angular blocky; extremely hard, very firm, very sticky and very plastic; common very fine, few medium roots; common very fine, few fine and medium tubular pores; many distinct pressure faces on peds; 20 percent gravel and 5 percent cobbles; neutral (pH 6.6); abrupt wavy boundary. (18 to 38 cm thick)

Bq--46 to 56 cm; pink (7.5YR 8/4) very gravelly sandy clay loam, brown (7.5YR 5/4) moist; massive; very hard, firm, brittle; common very fine tubular pores; 30 percent strongly silica-cemented lenses and irregular masses; 40 percent gravel, 10 percent cobbles and 2 percent stones; continuous brittle matrix; moderately alkaline (pH 8.0); abrupt broken boundary. (0 to 20 cm thick)

Bqkm--56 to 58 cm; very pale brown (10YR 8/2) indurated duripan, very pale brown (10YR 7/3) moist; massive; extremely hard, extremely firm; continuous indurated duripan with a thin (3 to 5 mm) laminar cap; many medium filaments and soft masses of carbonate in lower part; abrupt wavy boundary. (1.2 to 25 cm thick).

R--58 cm; unweathered rhyolite.

TYPE LOCATION: Humboldt County, Nevada; approximately 15 miles east of McDermitt; about 760 feet west and 1900 feet south of the northeast corner of section 5, T. 47 N., R. 41 E.; USGS Mahogany Spring 7.5 minute topographic quadrangle; latitude 41 degrees 59 minutes 40 seconds N and longitude 117 degrees 22 minutes 07 seconds W; WGS84 Decimal Degrees 41.9944444 latitude, -117.3686111 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Moist in winter and spring, usually dry July through mid-October; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 6 to 8 degrees C.
Mollic epipedon thickness: 18 to 36 cm, commonly includes the upper part of the argillic horizon.
Depth to duripan: 50 to 76 cm.
Depth to bedrock: 53 to 100 cm.
Other features: Thin E horizons are present in some pedons.

Particle-size control section - Clay content: Averages 60 to 70 percent.
Rock fragments: 15 to 35 percent, mainly gravel. Upper subhorizons are cobbly in some pedons.

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

Bt horizons
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 2 through 4 moist.
Chroma: 2 or 3.
Structure: Prismatic or blocky.
Consistence: Hard, very hard or extremely hard, dry.

Bq horizons (when present)
Hue: 7.5YR or 10YR.
Value: 7 or 8 dry, 5 through 7 moist.
Chroma: 2 through 4.
Texture: Very gravelly sandy clay loam, very gravelly loam, very gravelly clay loam.
Clay content: 18 to 35 percent.
Rock fragments: 35 to 60 percent, mainly gravel.
Consistence: Very hard or hard, dry.
Reaction: Slightly alkaline or moderately alkaline.
Cementation: Continuous brittle matrix with common to many strongly cemented lenses.
Other features: Discontinuous laminar layers of silica 1 to 5 mm thick are in some pedons.

Bqm and Bqkm horizons
Value: 7 or 8 dry, 6 or 7 moist.
Chroma: 1 through 3.

COMPETING SERIES: This is the Donna series. Donna soils are more than 100 cm to hard bedrock.

GEOGRAPHIC SETTING: Charwell soils are on volcanic flowrock plateaus and hills. These soils formed in residuum derived from volcanic rocks with minor amounts of loess and volcanic ash. Slopes are 0 to 30 percent. Elevations are 1,740 to 2,135 meters. The climate is cool, semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 300 to 400, mean annual temperature is 4 to 7 degrees C, and the frost-free season is 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Devada, Ninemile and Walti soils. All of these soils lack duripans. In addition, Devada and Ninemile soils are shallow to hard bedrock. Walti soils have less than 60 percent clay in their control sections.

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

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly low sagebrush, Idaho fescue and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: Northern Nevada and southeast Oregon. These soils are not extensive. MLRA 25.

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

SERIES ESTABLISHED: Humboldt County, Nevada, East Part, 1993.

REMARKS: Diagnostic horizons and features recognized in this pedon area:
Mollic epipedon - The zone from the soil surface to about 25 cm (A1, A2 and Bt1 horizons).
Abruptic feature - An abrupt texture change between the A and Bt horizons.
Argillic horizon - The zone from about 20 to 46 cm (Bt1 and Bt2 horizons).
Duripan - The indurated zone from about 56 to 58 cm (Bqkm horizon).
Aridic feature - Aridic soil moisture regime bordering on xeric.
Particle-size control section - The zone from 20 to 46 cm (Bt1 and Bt2 horizons).

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National Cooperative Soil Survey
U.S.A.